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Males Have Larger Skeletal Size and Bone Mass Than Females, Despite Comparable Body Size
Abstract
Gender differences in fractures may be related to body size, bone size, geometry, or density. We studied this in 18-year-old males (n = 36) and females (n = 36) matched for height and weight. Despite comparable body size, males have greater BMC and BMD at the hip and distal tibia and greater tibial cortical thickness. This may confer greater skeletal integrity in males.
Gender differences in fractures may be related to body size, bone size, geometry, or density. We studied this in males (n = 36) and females (n = 36; mean age = 18 years) pair-matched for height and weight.
BMC, bone area (BA), and BMD were measured in the spine and hip using DXA. Distal tibia was measured by pQCT.
Males had a higher lean mass (92%) compared with females (79%). No gender differences were observed for vertebral BMC or vertebral height, although males had greater width and thus BA at the spine. Males had greater BMC and BA at the femoral neck and total femur (p < 0.02). Geometric variables of the hip including neck diameter and neck-axis length were also greater in males (p < 0.02). There was greater cross-sectional moment of inertia, safety factor, and fall index in males (all p < 0.02). Males had greater tibial BMC, volumetric BMD, and cortical area and thickness compared with females (p < 0.01), with both greater periosteal circumference (p = 0.011) and smaller endosteal circumference (p = 0.058). Statistically controlling for lean mass reduced gender differences, but males still had 8% higher hip BMD (p = 0.24) and 5.3% higher total tibial BMD (p = 0.05). A subset of males and females were matched (n = 14 pairs) for total hip BA. Males in this subset still had greater BMC and BMD at the total hip (p < 0.05) than females, despite similar BA. In summary, despite comparable body size, males have greater BMC and BMD than females at the hip and distal tibia but not at the spine. Differences in BMC and BMD were related to greater cortical thickness in the tibia. We conclude that differences in bone mass and geometry confer greater skeletal integrity in males, which may contribute to the lower incidence of stress and osteoporotic fractures in males.
... 66 Females are up to four times more likely to sustain a stress fracture than males [2]. It has 67 been hypothesized that sex-related differences in tibial diaphysis cross-sectional geometry (e.g., 68 periosteal circumference and cortical thickness) may contribute to the elevated risk of stress 69 fractures observed in females [10,11]. We recently used a statistical appearance model, describing 70 variations in tibia-fibula geometry and density in a young physically active population, in 71 combination with the finite element method to evaluate sexual dimorphism and its influence on 72 bone strain [12]. ...
... The purpose of this study was to cross-validate our previous findings of sex-related 78 differences in tibia-fibula bone geometry, density, and finite element-predicted bone strain in an 79 entirely new cohort of young physically active adults. Previous studies examining tibial sexual 80 dimorphism using transverse cross-sections observed smaller bone size relative to stature in 81 females when compared to males [10,11,13]. Based on these observations and our previous results 82 for the whole tibia-fibula complex, we hypothesized that when controlling for bone size the ...
... The purpose of this study was to evaluate sex-related differences in tibia-fibula bone geometry, adds strong support to the hypothesis that sexual dimorphism in tibial geometry may contribute to 262 the elevated risk of stress fracture in females when compared to males [10,11] 263 Differences in sex-related density distributions near the endocortical surface were more 264 exaggerated in the validation cohort analyzed in this study when compared to the model cohort. ...
Females are up to four times more likely to sustain a stress fracture than males. Our previous work, using statistical appearance modeling in combination with the finite element method, suggested that sex-related differences in tibial geometry may increase bone strain in females. The purpose of this study was to cross-validate these findings, by quantifying sex-related differences in tibia-fibula bone geometry, density, and finite element-predicted bone strain in a new cohort of young physically active adults. CT scans of the lower leg were collected for fifteen males (23.3 ± 4.3 years, 1.77 ± 0.09 m, 75.6 ± 10.0 kg) and fifteen females (22.9 ± 3.0 years, 1.67 ± 0.07 m, 60.9 ± 6.7 kg). A statistical appearance model was fit to each participant’s tibia and fibula. The average female and male tibia-fibula complex, controlled for isotropic scaling, were then calculated. Bone geometry, density, and finite element-predicted bone strains in running were compared between the average female and male. The new cohort illustrated the same patterns as the cohort from the previous study: the tibial diaphysis of the average female was narrower and had greater cortical bone density. Peak strain and the volume of bone experiencing ≥ 4000 με were 10% and 80% greater, respectively, in the average female when compared to the average male, which was driven by a narrower diaphysis. The sex-related disparities in tibial geometry, density, and bone strain described by our previous model were also observed in this entirely new cohort. Disparities in tibial diaphysis geometry likely contribute to the elevated stress fracture risk observed in females.
... The higher osteoporosis prevalence in females may be attributed to many factors. First, females have lighter, thinner, and lower bone density than males [9]. Second, pregnancy and lactation decreased bone deposition in bone [10]. ...
... The overall OPB scale score ranged from 7-35, where higher scores indicated higher OPB. According to her overall score, the participants were considered to have low (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21) or high (22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) OPB. The Cronbach alpha coefficient was used to test the reliability of this scale, and the results indicated good reliability with a value of (r = 0.82). ...
Osteoporosis is a silent chronic disease, and many people did not discover it until they were diagnosed with a fracture. Therefore, regular scanning and appropriate Osteoporosis Preventive Behaviors (OPB) are the management cornerstone. OPB is strongly affected by personal knowledge and health beliefs. This study explores the role of knowledge and health beliefs as determinants of OPB among perimenopausal women. This cross-sectional study was performed on 1075 perimenopausal women in Najran City, Saudi Arabia, from January 2023 to March 2023. The data collection instrument is a self-reported questionnaire consisting of basic data, the OPB scale, an osteoporosis knowledge assessment tool, and the osteoporosis health belief scale. The current study results showed that approximately one-quarter (27.8%) of the study participants had high OPB with an overall mean of 20.83 ± 5.08 grade. The group practicing high OPB demonstrated a higher knowledge mean (11.37 ± 2.99) than the low OPB group (9.93 ± 3.51). In addition, all health beliefs constructs significantly differed among the low and high OPB groups (p ˂ 0.05). The participant’s age, occupational status, educational level, attendance of training courses, and history of bone fractures were significantly associated with high OPB. Osteoporosis knowledge, perceived susceptibility, perceived seriousness, exercises’ perceived benefits, and health motivations are positive predictors of high OPB (p ˂ 0.05). The study concluded that osteoporosis-related knowledge and health beliefs—especially perceived susceptibility, perceived seriousness, exercises’ perceived benefits, and health motivations—are positive predictors of high OPB. The health belief model can be an effective tool used to determine high-risk groups who practice low OPB and build need-based educational interventions.
... With respect to bone morphology, the differences in bone structure and strength between males and females are substantial. Males tend to have a more robust trabecular bone network and larger cortex compared to females [51,52], but cortical bone density tends to be greater in females vs males [53]. Since 20 % of our study sample was male, we performed sensitivity analyses excluding male subjects to minimize potential confounding of sex. ...
... Overall, the results of these sensitivity analyses suggest that our main findings were likely not attributed to sex confounding. Since distinct differences in bone biology [52], as well as metabolic response to food intake exist between males and females [57,58], there is a need to understand sexrelated differences with respect to gut-bone cross-talk. ...
Background: Studies in adults indicate that macronutrient ingestion yields an acute anti-resorptive effect on bone, reflected by decreases in C-terminal telopeptide (CTX), a biomarker of bone resorption, and that gut-derived incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), facilitate this response. There remain knowledge gaps relating to other biomarkers of bone turnover, and whether gut-bone cross-talk is operative during the years surrounding peak bone strength attainment. This study first, describes changes in bone resorption during oral glucose tolerance testing (OGTT), and second, tests relationships between changes in incretins and bone biomarkers during OGTT and bone micro-structure. Methods: We conducted a cross-sectional study in 10 healthy emerging adults ages 18–25 years. During a multi-sample 2-hour 75 g OGTT, glucose, insulin, GIP, GLP-1, CTX, bone-specific alkaline phosphatase (BSAP), osteocalcin, osteoprotegerin (OPG), receptor activator of nuclear factor kappa-β ligand (RANKL), sclerostin, and parathyroid hormone (PTH) were assayed at mins 0, 30, 60, and 120. Incremental areas under the curve (iAUC) were computed from mins 0–30 and mins 0–120. Tibia bone micro-structure was assessed using second generation high resolution peripheral quantitative computed tomography. Results: During OGTT, glucose, insulin, GIP, and GLP-1 increased significantly. CTX at min 30, 60, and 120 was significantly lower than min 0, with a maximum decrease of about 53 % by min 120. Glucose-iAUC0-30 inversely correlated with CTX-iAUC0-120 (rho = -0.91, P
... Thus, this cross-sectional study design is capable of investigating variation in the effects, across PMHS, of the subject-level variables often used to assume patterns of bone quality and injury risk on the quantity, distribution, and mineralisation of the cortex of the radius. The differential patterns between males and females in radius cortical bone response to changes in age and differences in height, further support previous findings that females are not simply smaller versions of males [15,16,18,20,26] . Similar to previous results [16] for the tibia, some of the data presented here for the non-weight bearing radius suggest sexual dimorphism in bone functional adaptation to systemic effects of age and body size represented by height. ...
... IRC- [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] IRCOBI conference 2021 ...
Persistently high frequency of forearm fractures in frontal and side impacts coupled with their long-term deleterious effects demands an in-depth understanding of variation in skeletal response to loading. Previous work has highlighted the differential impact of subject-level variables on bone quality between males and females. The purpose of this study was to evaluate effects of sex on variation in cortical bone morphometrics of the radius. Quantitative computed tomography analyses were performed on n=150 ex vivo post-mortem human subject radii from 96 males and 54 females. Morphometrics that represent bone quantity, cross-sectional distribution, whole-bone geometry, and mineralisation were quantified in the radius diaphysis. Females demonstrated significantly smaller cortical morphometric parameters (p<0.003) with the exception of whole-bone geometry and mineralisation (p>0.81). Sex-specific linear regressions demonstrate significant increases in some parameters with age in males (p<0.004) however, the amount of bone and mineralisation decreased with age in females (p<0.001). Females appeared to be more sensitive to changes in height and demonstrated positive relationships in more morphometrics than males. Multivariate regressions analysing combined effects of age and height explained more variation in morphometrics than age or height alone. The sex-specific effects of subject-level variables on cortical bone indicate varying mechanisms of bone functional adaptation that should be accounted for in injury risk predictions rather than body size-based scaling techniques.
... Bone geometry and density are two factors that influence bone strain magnitude. It has been hypothesized that differences in transverse cross-sectional size, cortical thickness, and condyle size between males and females contribute to the greater risk of stress fracture in females when compared to males [7][8][9]. In current literature, characterization of geometry, density, and estimates of bone strength within and between sex and injury status groups has largely relied on simple measures such as cortical area, cortical thickness, section modulus, polar strength-strain index, and bone mineral content measured at transverse cross-sections. ...
... In current literature, characterization of geometry, density, and estimates of bone strength within and between sex and injury status groups has largely relied on simple measures such as cortical area, cortical thickness, section modulus, polar strength-strain index, and bone mineral content measured at transverse cross-sections. [1,7,10]. Bone strain is a complex function of bone geometry and density distribution, and can be directly estimated using subject-specific finite element models [11]. ...
Tibial stress fracture is a common injury in runners and military personnel. Elevated bone strain is believed to be associated with the development of stress fractures and is influenced by bone geometry and density. The purpose of this study was to characterize tibial-fibular geometry and density variations in young active adults, and to quantify the influence of these variations on finite element-predicted bone strain. A statistical appearance model characterising tibial-fibular geometry and density was developed from computed tomography scans of 48 young physically active adults. The model was perturbed ±1 and 2 standard deviations along each of the first five principal components to create finite element models. Average male and female finite element models, controlled for scale, were also generated. Muscle and joint forces in running, calculated using inverse dynamics-based static optimization, were applied to the finite element models. The resulting 95th percentile pressure-modified von Mises strain (peak strain) and strained volume (volume of elements above 4000 με) were quantified. Geometry and density variations described by principal components resulted in up to 12.0% differences in peak strain and 95.4% differences in strained volume when compared to the average tibia-fibula model. The average female illustrated 5.5% and 41.3% larger peak strain and strained volume, respectively, when compared to the average male, suggesting that sexual dimorphism in bone geometry may indeed contribute to greater stress fracture risk in females. Our findings identified important features in subject-specific geometry and density associated with elevated bone strain that may have implications for stress fracture risk.
... 6 On the other hand, studies on the anatomy of the hip joint have also shown anatomical differences based on gender, especially on the femoral side. 7,8 When we consider these differences, women tend to have a shorter femoral neck, a thinner femoral shaft, a lower femoral neck angle and a lower femoral offset. 7,8 It is beneficial to consider these differences in hip replacement applications. ...
... 7,8 When we consider these differences, women tend to have a shorter femoral neck, a thinner femoral shaft, a lower femoral neck angle and a lower femoral offset. 7,8 It is beneficial to consider these differences in hip replacement applications. ...
Aim:
This study aims to determine the gender differences in hip joint functional anthropometric measurement values in Turkish adults.
Materials and Methods:
Digital pelvis anterior-posterior radiographs of 300 randomly selected patients were analyzed. In these radiographs, reference lines were drawn and femoral neck-shaft angle (NSA), hip rotation center (HRC), abductor moment arm (AMA), body weight moment arm (BMA) were calculated. The relationship of the distribution of measurement results with gender and age was examined.
Results:
It was determined that the mean NSA scores in men were significantly higher than in women ( p <0.05). It was determined that AMA value was significantly higher in men and BMA value was significantly higher in women ( p <0.05). BMA/AMA ratio was found to be statistically significantly higher in women ( p <0.005).
Conclusion:
Statistically significant differences were found between men and women in the mean of AMA, BMA and BMA/AMA in the Turkish population.
... The study reported a higher SSI at the tibia compared to Greene et al. [10]. Despite the similar age profile of the study cohorts, Greene et al. [10] recruited male and female jockeys and this may have resulted in a lower average SSI [61]. Moreover, a high dropout rate was reported following the clinical trial leading to a reduced sample size for baseline analysis [55]. ...
... The BMD values at the LS and total hip were significantly higher in female than male jockeys; however, there was no statistical difference at the femoral neck. Lower spinal BMD in male jockeys compared to female jockeys is contrary to the general population [13], while gender differences at the femoral neck are expected as males possess greater bone volume and bone shape at the hip and femoral neck [61]. Currently, 15% of professional jockeys in Ireland are female, an increase of 8% since 2017 suggesting, as female jockey participation continues to increase in horse racing, further research is required to investigate the effects of weight-making practices on the bone health in female jockeys. ...
Jockeys are unlike other weight-making athletes as the sport of horse racing requires strict weight management to meet the racing stipulations, protracted working hours and an extended racing season with limited downtime. Several studies have reported on the body composition and bone status of male and female professional and retired jockeys, yet the variety of assessment techniques, lack of standardised testing protocols and classification inconsistency make interpretation and comparison between studies problematic. This review aimed to appraise the existing body composition and bone health evidence in jockeys and evaluate the assessment methods and classification criteria used. Dual-energy X-ray absorptiometry (DXA) has been used most frequently in jockey research to assess body composition and bone status, while various generic skinfold equations have been used to predict body fat percentage. Evidence indicates flat jockeys are now taller and heavier than the data reported in earlier studies. Absolute fat mass has steadily increased in male jockeys in the last decade. The bone status of male jockeys remains a concern as constant low bone density (BMD) is evident in a large percentage of young and experienced professional jockeys. Due to limited studies and variations in assessment methods, further research is required to investigate bone turnover markers in male and female jockeys. A standardised testing protocol using internationally recognised assessment guidelines is critical for the accurate interpretation and evaluation of body composition and bone health measurements. Furthermore, establishing jockey-specific BMD and bone turnover reference ranges should be considered using existing and future data.
... This is attributed to higher rates of low energy availability in females, including runners [39,40]. Sexual dimorphism may also contribute, with men having larger bones and higher bone mass than females despite comparable body size [41]. ...
Bone stress injury (BSI) is a common overuse injury that can result in prolonged time away from sport. Limited studies have characterized the use of extracorporeal shockwave therapy (ESWT) for the treatment of BSI. The purpose of this study was to describe the use of ESWT for the management of BSI in runners. A retrospective chart review was performed to identify eligible patients in a single physician's clinic from 1 August 2018 to 30 September 2022. BSI was identified in 40 runners with 41 injuries (28 females; average age and standard deviation: 30 ± 13 years; average pre-injury training 72 ± 40 km per week). Overall, 63% (n = 26) met the criteria for moderate- or high-risk Female or Male Athlete Triad categories. Runners started ESWT at a median of 36 days (IQR 11 to 95 days; range 3 days to 8 years) from BSI diagnosis. On average, each received 5 ± 2 total focused ESWT treatments. Those with acute BSI (ESWT started <3 months from BSI diagnosis) had an average return to run at 12.0 ± 7.5 weeks, while patients with delayed union (>3 months, n = 3) or non-union (>6 months, n = 9) had longer time for return to running (19.8 ± 14.8 weeks, p = 0.032). All runners returned to pain-free running after ESWT except one runner with non-union of grade 4 navicular BSI who opted for surgery. No complications were observed with ESWT. These findings suggest that focused ESWT may be a safe treatment for the management of BSI in runners.
... Second, women's bodies are more susceptible to calcium and vitamin D depletion due to recurrent pregnancy and lactation. Third, during the menopausal period, estrogen and progesterone depletion have a negative impact on bone metabolism [41][42][43]. However, osteoporosis is an important health concern for both males and females. ...
Osteoporosis is a chronic bone disease affecting both men and women, but it is more prevalent in women. Promoting a healthy lifestyle among adults, particularly women, is crucial in preventing and reducing the osteoporosis impact. This study aimed to compare the osteoporosis knowledge, health beliefs and preventive behaviors among adult male and female in Najran city Saudi Arabia. This cross-sectional study was performed on 516 males and 581 females in Najran City, Saudi Arabia, from January to April 2023. The data collection instrument is a self-reported online questionnaire consisting of basic data, the Osteoporosis Preventive Behavior (OPB) scale, the osteoporosis knowledge assessment tool, and the osteoporosis health belief scale. The results revealed that male participants had a higher OPB (26.70) than females (20.32). However, females have a higher knowledge (10.71), perceive themselves as more susceptible to osteoporosis (20.34) and had higher exercise barriers (20.11) compared to males (9.97, 18.79 and 19.20, respectively). Statistically significant correlations (p < 0.001) were observed between OPB, osteoporosis knowledge (r = 0.26), perceived susceptibility (r = 0.33), severity (r = 0.53), exercise (r = 0.54) and calcium (r = 0.33) benefits, exercise (r = 0.40) and calcium (r = 0.81) barriers and health motivation (r = 0.37). The study concluded significant disparities between males and females regarding osteoporosis-related knowledge, preventive behaviors, perceived susceptibility, severity, and exercise perceived barriers. The results suggest gender-based educational interventions to enhance OPB by addressing osteoporosis-related knowledge, perceived susceptibility, seriousness, benefits, and health motivation.
... 45 On the other hand, other studies claimed that gender did not influence screw stability. [46][47][48] In the current study, comparing 45 degreewith 90-degree insertion angle showed that more screw stability was found in the 90° group with a statistically significant difference between the two groups (P-value <.01). The present findings seem to be consistent with other research in which greater screw stability was found when the 90-degree insertion angle was performed. ...
Background and objectives:
The intrusion of anterior teeth is a routine procedure in orthodontics, which has been performed efficiently with the help of mini-screws in the anterior region, especially the upper maxilla. This study aimed to investigate the effect of insertion angle and sociodemographic features on the success rate of mini-screws at the anterior maxillary region.
Materials and methods:
Twenty-nine patients (18 Females and 11 Males) aged 18-40 years old were involved in the current study. A split-mouth design was carried out in which recruited patients needed bilateral anterior screws at the labial bone in the region of the incisor for the intrusion of upper anterior incisor teeth as part of their orthodontic treatment with a fixed appliance (upper right side received 90-degree insertion angle mini-screw and 45° for left side) using a surgical guide fabricated from patients CBCT and intraoral scans. The mini-screws were inserted at the attached gingiva bilaterally to achieve intrusion of upper anterior teeth with a power chain ligated from the main archwire to the anterior min-implants. The patient was recalled monthly for orthodontic appliance activation and screw assessment for 6 months. The intrusion force was 15 g on each side.
Results:
The results of the study showed that screw stability was higher in the male group than the female group at the 6th monthly follow-up visit with a statistically significant difference between both genders (P = .044). Concerning insertion angle, results showed a statistically significant difference between 45° and 90° as an insertion angle with a P-value <.01 in most of the follow-up months.
Conclusion:
This study found that male patients with mini-screws inserted at 90° showed greater screw stability over time.
... Nieves et al conducted a study comparing bone mass between males and females and found that males had larger skeletal size and bone mass despite comparable body size, which could contribute to their higher fracture incidence. 18 Regarding anatomical sites, fractures most commonly occur in the upper extremities. The distal radius and ulna are frequently affected, followed by the clavicle, humerus, and fingers. ...
Fractures in children and adolescents are a significant public health concern. The incidence of fractures varies based on age, sex, and anatomical site, with falls, sports-related injuries, motor vehicle accidents, child abuse, and pathological conditions identified as primary causes. Risk factors such as age, sex, physical activity, bone mineral density, body composition, and genetic factors contribute to fracture occurrence. Preventive measures targeting modifiable risk factors and promoting safety in physical activities are crucial for reducing the burden of fractures in children and adolescents. This review aims to provide a comprehensive understanding of the epidemiology and etiology of fractures in children and adolescents. Understanding the epidemiological patterns and etiological factors can guide the development of effective prevention strategies and optimize fracture management in this population.
... Our study shows that OOs are more common in males than females, which is a fact already reflected in the literature. Although a reason for this predilection has not been previously proven, we believe it is due to a higher bone mass in males [21]. Most cases clustered between the ages of six and 26 years, an observation previously described in studies, which is likely secondary to greater bone growth during this period [22]. ...
Introduction Osteoid osteoma is a benign condition of the bone, usually affecting young males. This retrospective study explores the demographics of osteoid osteomas in the Northern Irish population. It also aims to audit the practice of CT-guided radiofrequency ablation of osteoid osteomas at a major orthopaedic centre in Belfast, Northern Ireland, and to investigate the possible causes of treatment failure. Methods Forty-seven osteoid osteoma patients, diagnosed based on clinico-radiologic features and treated with CT-guided radiofrequency ablation, were found eligible for inclusion and analysis. We collected data from electronic health records (March 2011 to May 2022) and reviewed the radiological images and associated reports. Information about demographics, clinical indices, operative technique, clinical outcomes, biopsy results, and follow-up were also gathered. Data were then analysed using IBM SPSS Statistics for Mac, version 28.0.1.1 (14) (IBM Corp., Armonk, NY). Results The average age of patients was 19.3 years, with a male-to-female predilection of 2.1:1. The proximal and mid-tibial shafts were the most frequently involved sites. On average, patients had symptoms for 15.6 months, while the mean treatment delay period was 6.9 months. Primary clinical success was observed in 37 patients (78.7%), while ten patients had a clinical failure. Two out of the 10 patients with treatment failure underwent subsequent successful ablations, raising the secondary clinical success rate to (83.0%). Chi-Square association tests found no correlation between primary treatment outcomes and other qualitative variables (gender, bone type, lesion location, and Kayser classification). Moreover, binary logistic regression tests found no predictability of age and treatment delay on treatment outcomes. The overall observed complication rate was 4%, with only one significant side effect reported (third-degree skin burn). Conclusion We concluded that the demographics of osteoid osteomas in the Northern Irish population are comparable to what is previously established in the literature. Furthermore, we reasoned that CT-guided radiofrequency ablation is an efficient, safe, and effective minimally invasive technique in the management of osteoid osteomas.
... Furthermore, the phenotypic differences between females and males in bone morphology, mineral density, and fracture resistance are not surprising since bone has been well established as a tissue that is regulated in a sexually dimorphic manner through murine studies and clinical observations [70][71][72][73][74]. However, sex-specific regulation of skeletal stability by miRs has been relatively unexplored, and to our knowledge, this is the first study to highlight the sexually dimorphic role of miR181a/b-1 in skeletal physiology or pathology. ...
Bone derives its ability to resist fracture from bone mass and quality concurrently; however, many questions about the molecular mechanisms controlling bone quality remain unanswered, limiting the development of diagnostics and therapeutics. Despite the increasing evidence on the importance of miR181a/b-1 in bone homeostasis and disease, whether and how osteocyte-intrinsic miR181a/b-1 controls bone quality remains elusive. Osteocyte-intrinsic deletion of miR181a/b-1 in osteocytes in vivo resulted in compromised overall bone mechanical behavior in both sexes, although the parameters affected by miR181a/b-1 varied distinctly based on sex. Furthermore, impaired fracture resistance in both sexes was unexplained by cortical bone morphology, which was altered in female mice and intact in male mice with miR181a/b-1-deficient osteocytes. The role of miR181a/b-1 in the regulation of osteocyte metabolism was apparent in bioenergetic testing of miR181a/b-1-deficient OCY454 osteocyte-like cells and transcriptomic analysis of cortical bone from mice with osteocyte-intrinsic ablation of miR181a/b-1. Altogether, this study demonstrates the sexually dimorphic regulation of cortical bone morphology and mechanical properties and the control of osteocyte bioenergetics by miR181a/b-1, hinting at the role of osteocyte metabolism in the regulation of mechanical behavior.
... BMD is generally used as a comprehensive measure of bone quality and to identify fracture risk. Sex-based differences in skeletal structure (Nieves et al., 2005) and skeletal aging (Riggs et al., 2004) are widely known and have even been observed in structural properties associated with bone strength (Agnew et al., 2018). The results from the present study support differences between males and females in rib structural properties and BMC but not in the widely used BMD metric (Figure 3). ...
Rib fractures are associated with high rates of morbidity and mortality. Improved methods to assess rib bone quality are needed to identify at-risk populations. Quantitative computed tomography (QCT) can be used to calculate volumetric bone mineral density (vBMD) and bone mineral content (BMC) which may be related to rib fracture risk. The objective of this study was to determine if vBMD and BMC from QCT predict human rib structural properties. 127 mid-level (5 th-7 th) ribs were obtained from adult female (n=67) and male (n=60) post-mortem human subjects (PMHS). Isolated rib QCT scans were performed to calculate vBMD and BMC. Each rib was subsequently tested to failure in a dynamic simulated frontal impact and structural properties, peak force (FPeak), percent displacement (δPeak), linear structural stiffness (K), and total energy (UTot) were calculated. vBMD demonstrated no significant differences between sexes (p>0.05), however, males had a higher BMC than females (p<0.001). Further, sex-specific differences were observed in all rib structural properties except for δPeak (p>0.05). Age had a significant relationship with both vBMD and BMC (p<0.001) but only in females when separated by sex (p<0.001). vBMD predicted FPeak, δPeak, K, and UTot (R 2 = 9.2%-30.9%, p<0.05) but was not able to predict δPeak in males. Similarly, BMC also predicted all rib structural properties, except for δPeak in males, but explained more meaningful amounts of variation (R 2 = 22.2%-67.7%, p<0.001). When predicting rib structural properties, BMC captures sex-specific variations in bone size that are obfuscated by vBMD and contribute to the biomechanical response of the rib during mechanical loading. Incorporating BMC into assessments of injury risk may therefore provide additional insight into the multifaceted nature of rib bone quality and differential fracture resistance.
... One study of height and weight-matched groups of 18-year-old males (n = 36) and females (n = 36) found significantly greater BMC for males at the femoral neck (11%), femoral trochanter (27%), femoral shaft (10%), total proximal femur (16%) and proximal tibia (13%). 42 This study also showed significantly greater BMD in femoral neck (6%), femoral trochanter (6%), femoral shaft (7%) and proximal tibia (7%) in males compared to weight and height-matched females. 42 ...
Many transgender (trans) individuals utilize gender-affirming hormone therapy (GAHT) to promote changes in secondary sex characteristics to affirm their gender. Participation rates of trans people in sport are exceedingly low, yet given high rates of depression and increased cardiovascular risk, the potential benefits of sports participation are great. In this review, we provide an overview of the evidence surrounding the effects of GAHT on multiple performance-related phenotypes, as well as current limitations. Whilst data is clear that there are differences between males and females, there is a lack of quality evidence assessing the impact of GAHT on athletic performance. Twelve months of GAHT leads to testosterone concentrations that align with reference ranges of the affirmed gender. Feminizing GAHT in trans women increases fat mass and decreases lean mass, with opposite effects observed in trans men with masculinizing GAHT. In trans men, an increase in muscle strength and athletic performance is observed. In trans women, muscle strength is shown to decrease or not change following 12 months of GAHT. Haemoglobin, a measure of oxygen transport, changes to that of the affirmed gender within 6 months of GAHT, with very limited data to suggest possible reductions in maximal oxygen uptake as a result of feminizing GAHT. Current limitations of this field include a lack of long-term studies, adequate group comparisons and adjustment for confounding factors (e.g. height and lean body mass), and small sample sizes. There also remains limited data on endurance, cardiac or respiratory function, with further longitudinal studies on GAHT needed to address current limitations and provide more robust data to inform inclusive and fair sporting programmes, policies and guidelines.
... Additionally, because only young male knees were studied, there were no confounding effects of age, osteoarthritis, trauma, or sex. 16,26 The limitations of the study include the use of cadaveric knees with representative muscle forces in lieu of in vivo experiments; accurate biplanar radiographic kinematic measures are feasible for the latter and could be used to confirm or refute the present findings. A further limitation is that we used only male knees because of a lack of a sufficiently large sample of young female knees to be able to study sex differences, so this could be a goal for future studies. ...
Background
It is not known mechanistically whether a steeper lateral posterior tibial slope (LTS) leads to an increase in anterior tibial translation (ATT) as well as internal tibial rotation (ITR) during a given jump landing.
Hypothesis
A steeper LTS will result in increased ATT and ITR during simulated jump landings when applying knee compression, flexion, and internal tibial torque of increasing severity.
Study Design
Descriptive laboratory study.
Methods
Seven pairs of cadaveric knees were harvested from young male adult donors (mean ± SD; age, 25.71 ± 5.53 years; weight, 71.51 ± 4.81 kg). The LTS of each knee was measured by a blinded observer from 3-T magnetic resonance images. Two sets of 25 impact trials of ∼700 N (1× body weight [BW] ±10%) followed by 2 sets of 25 trials of 1400 N (2× BW ±10%) were applied to a randomly selected knee of each pair. Similarly, on the contralateral knee, 2 sets of 25 impact trials of ∼1800 N (2.5× BW ±10%) followed by 2 sets of 25 trials of ∼2100 N (3× BW ±10%) were applied. Three-dimensional knee kinematics, including ATT and ITR, were measured at 400 Hz using optoelectronic motion capture. Two-factor linear mixed effect models were used to determine the relationship of LTS to ATT and ITR as impact loading increased.
Results
As LTS increased, so did ATT and ITR during increasingly severe landings. LTS had an increasing effect on ATT (coefficient, 0.50; 95% CI, 0.29-0.71) relative to impact force (coefficient, 0.52; 95% CI, 0.50-0.53). ITR was proportional to LTS (coefficient, 1.36; 95% CI, 0.80-1.93) under increasing impact force (coefficient, 0.49; 95% CI, 0.47-0.52). For steeper LTS, the increase in ITR was proportionally greater than the increase in ATT.
Conclusion
In male knee specimens, a steeper LTS significantly increased ATT and ITR during jump landings.
Clinical Relevance
Increases in ITR and ATT during jump landings lead to increased strain on the anterior cruciate ligament and are therefore associated with greater risk of ligament failure.
... Our subgroup analysis revealed higher risk of fracture in the underweight group in men than in women, unlike other studies [4]. Our plausible explanation for the disparity in fracture risk by sex is that men have larger bones and less adipose tissue than women [5]. Since the weight of bone remains relatively constant compared to muscle or fat tissue, the effect of low BMI on fracture risk may be more significant in males. ...
... Similarly, there were differences observed in male and female rat bone samples ( Figure 4). Physiologically, the bone is less dense in females as compared to that of males 19,20 . Our results suggest that the OCT technique may represent a feasible method for differentiate bone density in male and female, as a function of depth of light penetration. ...
Objective:
Optical Coherence Tomography (OCT) is a non-invasive imaging technique that produces cross-sectional images through biological tissues, allowing three-dimensional reconstruction and analysis. Aim was to evaluate if OCT may discriminate among tissues with different bone density and composition, by measuring the depth of light penetration in porcine and rat bone samples.
Materials and methods:
Two carpal bone samples (2 cm length) were harvested from the porcine forelimb and fixed overnight in 3.7% buffered formal saline. Following fixation, one sample was decalcified in a 1:1 mixture of 8% hydrochloric acid and 8% formic acid solution for three days, with solution changes each day. Samples were imaged using an OCT microscope. Furthermore, the calvaria, ulnar, alveolar and basal bone of the mandible of 6 male and 6 female rats were cleared of overlying soft tissues and scanned under OCT. The light penetration depth in each sample was measured using the software Image J, and Scattering Attenuation Microscopy.
Results:
In the mineralized bone the average depth (µm) and standard deviation (SD) of light penetration were 790.1±18.05 and 410.4±21.7 for periosteal and endosteal surface, respectively, and 507.3±21.03 for cross-section surfaces, while it was 858.4±32.03 for periosteal surface, 1150±26.9 for endosteal, and 627.3±31.8 for cross-section bone surfaces in demineralized porcine bone. There was a significant difference (p<0.001) in depth of light penetration between normal and de-mineralized bone for all regions evaluated. No systematic significant difference in light penetration depth between-gender was found at any site evaluated, while there were variations between sites (p<0.001). The OCT detected differences in bone mineral and porosity among gender (p<0.0001) CONCLUSIONS: This study suggests that OCT may represent a valuable technique to estimate local variations in bone mineral content.
... It has been reported that in comparison to females, males exhibited greater thickness of the cortical bone due most probably to higher OC peak levels. [33] Our findings too revealed that the mean OC levels in males were increased in comparison to females at each of the CSs. Literature reports have underlined the fact that in comparison to cancellous bone, OC is found to be higher in cortical bone. ...
Objectives
Growth evaluation methods have made great strides in the shift from radiologic to non-radiologic biomarkers. Osteocalcin (OC), a bone protein, has been reportedly used as a biomarker for osteoblastic bone formation. The present study aimed at evaluation of serum OC in Class II skeletal patterns for accurate assessment of pubertal growth spurt to facilitate functional jaw orthopedics during the growth period.
Material and Methods
Eighty subjects, comprising 38 males and 42 females with skeletal Class II malocclusion in the age range of 11–18 years, were recruited for the study. Human serum OC was quantitatively assessed with enzyme-linked immunosorbent assay. The cervical vertebral stages were assessed from lateral cephalograms. Statistical analysis for gender-wise comparison of mean serum levels of OC at each cervical stage (CS) and in the intervals of the CSs was carried out using Kruskal–Wallis test and for intergroup comparisons, Mann–Whitney U-test with Bonferroni’s correction was done.
Results
Gender-wise comparison of mean serum OC levels revealed that it was highest in CS2 in both males (72.24 ng/mL) and females (74.71 ng/mL) with another discernible peak in CS5 in males (66.82 ng/mL) and in CS6 in females (63.78 ng/mL), exhibiting thereby a circadian rhythm in bone modeling during the entire adolescent growth spurt.
Conclusion
Despite a pre-pubertal and a late pubertal spike in both the genders, the mean OC serum levels actually exhibited a circadian rhythmicity across all the CSs, exhorting thereby the importance of bone remodeling during the complete circumpubertal growth period.
... Nieves et al. found that men tend to have a higher percentage of lean body mass than women, and women also tend to lose bone mass faster [18]. A recent study found that, compared to men, postmenopausal women have a two-fold increase in osteopenia and a four-fold increase in osteoporosis rates [19]. ...
Background: Osteoporosis is commonly referred to as the “silent disease,” as bone loss is gradual and asymptomatic. In older women and men, osteoporosis can lead to increased bone fragility, thus increasing the risk of fractures. These fractures are associated with healthcare costs, physical disabilities, impaired quality of life, and mortality. Therefore, the study’s main objective was to assess the applicability of the osteoporosis self-assessment tool (OST) in predicting osteoporosis in Saudi postmenopausal women who are 60 years of age and older and to give a thorough understanding of how such a method can aid in the early diagnosis of osteoporosis in Saudi Arabia and give physicians enough time to treat it.
Methods: This study was done at King Abdulaziz Medical City, Riyadh, Saudi Arabia, where we included postmenopausal Saudi women 60 years of age and older who took the bone mineral density (BMD) test in the family medicine department. The approximate target population in this group, between the years 2016 and 2022, was 2969 patients. All data was taken from the BestCare database at King Abdulaziz Medical City in Riyadh. Data were typed in an Excel sheet (Redmond, USA), then transferred to the R Studio software. The data collection method was chart review, so no informed consent was needed from patients. Names and medical record numbers were not stored.
Results: The study included 2969 participants. According to the bone mineral density (BMD) T score results, 490 participants (16.5%) were normal, 1746 participants (58.8%) had osteopenia, and 733 participants (24.7%) suffered from osteoporosis. BMD T scores for normal, osteopenia, and osteoporosis participants were -0.6 (-0.9, -.3), -1.8 (-2.1), and -3 (-3.5, -2.7), consecutively. Estimated OSTI scores for those patients were 2 (0, 4), 1 (-2, 3), and -1 (-4, 1), consecutively. According to the OSTI score for normal participants, 4.29% were classified as being at high risk of osteoporosis. A high risk of osteoporosis was identified in 0.74% of those with osteopenia. 27.83% of osteoporosis patients were classified as being at high risk of osteoporosis. To differentiate normal individuals from those with osteopenia, the cutoff value with optimal sensitivity was 3.5. At such a cutoff value, the test sensitivity was 81.04%. To differentiate normal participants from those with osteoporosis, the cutoff value with optimal sensitivity was 2.5. At such a cutoff value, the test sensitivity was 86.49%. To differentiate osteopenia from osteoporosis patients, the cutoff threshold with optimal sensitivity was 1.5. At such a threshold, sensitivity was 78.44%.
Conclusion: OSTA is a simple and validated tool that can identify subjects at increased risk of osteoporosis. Its use could facilitate a more cost-effective use of BMD; by avoiding measurements in low-risk groups.
... Some previous studies have shown that even after controlling for body Values are partial correlation coefficient (P value) controlled by sex, age, height, weight, and ancestry *P < 0.05. size, males have greater bone volume and greater cross-sectional area in postcranial bones than females [41,42]. The present study clearly demonstrated that males have greater cortical thickness and greater width in the diaphysis of the humerus than females, even after controlling for other covariates, including height and weight (Fig 2 and Tables 1 and 3). ...
Cortical bone thickness is important for the mechanical function of bone. Ontogeny, aging, sex, body size, hormone levels, diet, behavior, and genetics potentially cause variations in postcranial cortical robusticity. However, the factors associated with cranial cortical robusticity remain poorly understood. Few studies have examined cortical robusticity in both cranial and postcranial bones jointly. In the present study, we used computed tomography (CT) images to measure cortical bone thicknesses in the cranial vault and humeral diaphysis. This study clearly showed that females have a greater cranial vault thickness and greater age-related increase in cranial vault thickness than males. We found an age-related increase in the full thickness of the temporal cranial vault and the width of the humeral diaphysis, as well as an age-related decrease in the cortical thickness of the frontal cranial vault and the cortical thickness of the humeral diaphysis, suggesting that the mechanisms of bone modeling in cranial and long bones are similar. A positive correlation between cortical indices in the cranial vault and humeral diaphysis also suggested that common factors affect cortical robusticity. We also examined the association of polymorphisms in the WNT16 and TNFSF11 genes with bone thickness. However, no significant associations were observed. The present study provides fundamental knowledge about similarities and differences in the mechanisms of bone modeling between cranial and postcranial bones.
... Physiologically, males have greater bone mass than females due to differences in skeletal muscle mass as well the effects of the male (testosterone) hormones which have an anabolic effect on the bones [59,60]. However, a study of PLWH in Malawi [61] reported lower BMD in males than females while another study indicated that females had lower BMD than males [7,4]. ...
Background
Bone demineralization in people living with HIV (PLWH) could be ameliorated by biomechanical loading of the musculoskeletal system which exerts an osteogenic stimulus. Therefore, we determined whether the bone mineral density (BMD) varied in weight-bearing and non-weight-bearing bones in PLWH, and its relationship with some risk factors (age, body mass index-BMI, duration of HIV, and height) of bone loss
Method
A cross-sectional observational study of 503 people living with HIV (PLWH) selected by convenience sampling at Enugu State University Teaching Hospital, Nigeria, was conducted from September 2015 to September 2016. The BMD of toe or weight-bearing (BMDtoe) and thumb or non-weight-bearing (BMDthumb) bones were measured with Xrite 331C densitometer and compared using independent t-test. Impact of the risk factors of bone loss and their relationships with the BMD were compared across the sexes using multivariate, and univariate regression analyses, at p < 0.05,two-tailed.
Result
The 352 HAART-experienced participants comprised of females(265/75.2%), males(62/17.6%) and others(25/7.1%) without gender specificity. Their demographics were: mean age = 37.2 ± 9.79years, BMI = 25.6 ± 5.06kg/m² and duration of HAART-exposure = 4.54 ± 3.51 years. The BMDtoe(-0.16 ± 0.65g/cm³) was higher(p < 0.05) than BMDthumb(-0.93 ± 0.44g/cm³), and differed across BMI classes(p = 0.000003;d = 0.998) unlike BMDthumb, and was accounted for in post hoc analysis by normal weight versus underweight BMI classes(p = < 0.001). BMDtoe was positively correlated with height (r = 0.13,r² = 0.0169;p < 0.05), and males were taller than females (p < 0.001). Females accounted for 90%(9/10) cases of osteopenia and 71.43% (5/7) osteoporosis. Males were older(p = 0.002) while females had greater BMI(p = 0.02), lower median BMDtoe(p = 0.005) and BMDthumb(p = 0.005).
Conclusion
Significant BMD variations across BMI classes in weight-bearing unlike non-weight-bearing bones is explained by biomechanical loading. Higher BMD in weight-bearing bones(toe), and lower BMDtoe in underweight BMI class (implying sub-optimal loading) suggest a role for osteogenic stimulus and fat metabolism in bone loss. Females being younger/heavier should have greater loading and osteogenic stimulus reinforced by lesser age-related BMD changes. Males being taller should have greater bone marrow adipose tissues that promote osteogenesis through paracrine mechanisms. Greater height and BMD in males than females are explained by sexual dimorphism in skeletal length and density. The greater BMD observed in the females’ weight-bearing than non-weight-bearing bones implies that loading also ameliorates the females’ physiological tendencies towards lower BMD.
... Likewise, recent work by Zwirner et al. produced sexindependent force and stress measurements [31]. Compared to work on load-bearing bones in humans, there is scarce literature differentiating the mechanical properties of male and female crania [48]. One probable factor for observing no differences was the comparable geometry in specimens between sex since specimen thickness and second moment of inertia are associated with the computation of bending stress and modulus. ...
The circumstances in which we mechanically test and critically assess human calvaria tissue would find relevance under conditions encompassing real-world head impacts. These conditions include, among other variables, impact velocities, and strain rates. Compared to quasi-static loading on calvaria, there is less reporting on the impact loading of the calvaria and consequently, there are relatively fewer mechanical properties on calvaria at relevant impact loading rates available in the literature. The purpose of this work was to report on the mechanical response of 23 human calvaria specimens subjected to dynamic 4-point bending impacts. Impacts were performed using a custom-built 4-point impact apparatus at impact velocities of 0.86 to 0.89 m/s resulting in surface strain rates of 2-3/s - representative of strain rates observed in vehicle collisions and blunt impacts. The study revealed comparable effective bending moduli (11-15 GPa) to the limited work reported on the impact mechanics of calvaria in the literature, however, fracture bending stress (10-47 MPa) was relatively less. As expected, surface fracture strains (0.21-0.25%) were less compared to studies that performed quasi-static bending. Moreover, the study revealed no significant differences in mechanical response between male and female calvaria. The findings presented in this work are relevant to many areas including validating surrogate skull fracture models in silico or laboratory during impact and optimizing protective devices used by civilians to reduce the risk of a serious head injury.
... Men also lose bone density in a different way to women, with trabecular bone loss occurring more by thinning of the trabeculae rather than a decrease in trabeculae number and connectivity seen in women. 7,8 This thinning, rather than loss, means men have a slower bone turnover state than women. As a result, the response to treatment with antiresorptive agents is less optimal than in women. ...
... Physiologically, males should have greater bone mass than their female counterparts due to differences in skeletal muscle mass as well as hormonal make-up of which the male (testosterone) hormones have an anabolic effect on the bones [59,60]. However, a study of PLWH in Malawi [61] reported lower BMD in males than in females while another study indicated that females had lower BMD than males [7,4]. ...
Background: Biomechanical loading exerts an osteogenic stimulus; thus, bone mineral
density(BMD) may vary in weight-bearing and non-weight-bearing bones. Therefore, weight-
bearing activities could modulate sex-, HAART- and HIV-related BMD loss.
Method: A cross-sectional observational study of 503 people living with HIV (PLWH) selected by
convenience sampling at Enugu State University Teaching Hospital, Nigeria, was conducted
from September 2015 to September 2016. The BMD of toe or weight-bearing(BMDtoe) and
thumb or non-weight-bearing(BMDthumb) bones were measured with Xrite 331C densitometer
and compared using independent t-test. Impact of the risk factors (age, weight, body mass
index-BMI, duration of HIV, height and types of HAART) of bone loss and their relationships
with the BMD were compared across the sexes using multivariate, and univariate regression
analyses, at p<0.05,two-tailed.
Result: Participants comprised of females(378/75.1%), males(89/17.7%) and others(36/7.16%)
without gender specificity, with mean age=37.2±9.79years, and BMI=25.6±5.06kg/m. HAART-
experienced participants’ (352/69.98%) mean HAART-exposure duration was 4.54±3.51years.
BMDtoe(-0.16±0.65g/cm3
) was higher(p<0.05) than BMDthumb(-0.93±0.44g/cm3
), and differed
across the BMI classes (p=0.000003;d=0.998), and was accounted for in post hoc analysis by normal
weight versus underweight BMI classes (p=<0.001). BMDtoe was positively correlated with height
(r=0.13,r2=0.0169;p<0.05), and males were taller than females(p<0.001). Females accounted for
90%(9/10) cases of osteopenia and 71.43%(5/7) osteoporosis. Males were older(p=0.002) while
females had greater BMI (p=0.02), lower median BMDtoe(p=0.005) and BMDthumb (p=0.005).Conclusion: Higher BMD in weight-bearing bones, and lower BMDtoe in underweight (sub-
optimal loading) BMI class suggest a role for osteogenic stimulus and fat metabolism in bone
loss. Females being younger/heavier, would have greater loading/osteogenic stimulus
reinforced by lesser age-related BMD changes. Males being taller would have greater bone
marrow adipose tissue that promote osteogenesis through paracrine mechanisms. Therefore,
higher BMD in males should be partly explained by height-related metabolic surrogates and
sex-hormonal differences. Greater BMD In females’ weight-bearing bones implies that loading
ameliorates physiological tendencies towards lower BMD.
... The reduction in serum creatinine and height was more pronounced among women. Women have less muscle and bone mass compared to men and the prevalence of premature menopause increases among women with kidney failure (32,33). These unfavorable environments likely increased the vulnerability of musculoskeletal system of women to further insults ...
Severe hyperparathyroidism predicts poor outcomes in patients with kidney failure. Mechanisms underlying the relationship between high parathyroid hormone (PTH) and decreased survival other than bone loss are largely unexplored. Recent evidence suggests the role of excess PTH in adipose tissue browning resulting in protein-energy wasting. The present retrospective observational study examined nutritional status among patients receiving maintenance hemodialysis with different degree of hyperparathyroidism. Seven hundred forty-five patients were categorized into four groups according to PTH levels: group 0, < 200; group 1, 200–599; group 2, 600–1,499; and group 3, ≥1,500 pg/ml. Group 0 was excluded because of the relationship between low PTH with aging and malnutrition. Patients in groups 1 and 2 were matched to group 3 by propensity score yielding 410 patients in the final analysis. Nutritional parameters at baseline and the preceding 1 and 2 years were examined. At baseline, lower serum albumin, creatinine/body surface area (Cr/BSA), height in female and higher percentage of patients with serum albumin < 38 g/L were observed in group 3 compared to groups 1 and 2. Higher PTH level was independently associated with serum albumin < 38 g/L and Cr/BSA < 380 μmol/L/m2. The longitudinal decline in serum albumin and Cr/BSA and the increase in the frequency of patients with serum albumin < 38 g/L were observed among patients in group 3. Between group comparisons confirmed a significant decline in serum albumin and Cr/BSA in association with an increase in the proportion of patients with serum albumin < 38 g/L and Cr/BSA < 380 μmol/L/m2 in group 3 compared to groups 1 and 2. Weight loss was more significant and was of greater magnitude among patients in group 3 compared to groups 1 and 2. Normalized protein catabolic rate in 3 groups were comparable. There was no significant difference in any of the nutritional parameters between groups 1 and 2. In conclusion, patients receiving maintenance hemodialysis with severe hyperparathyroidism showed deterioration of nutritional status compared to patients with moderate hyperparathyroidism and patients with PTH level in the recommended range. These findings support the role of extreme PTH level in protein-energy wasting emphasizing the importance of early management of hyperparathyroidism.
... Male globe volumes being larger than female globe volumes could be due to males having a bigger body habitus than females, and this leads to male organs being bigger than the corresponding female organs. [18,19] As the relationships of globe volume in inter-sex and intrasex groups remain consistent using either the ellipsoid or spherical formula, this could mean that the two formulae are interchangeable when used to approximate globe volume. It is also noteworthy that while both formulas showed consistent relationships with age and gender, the spherical formula approximated a volume significantly larger than the ellipsoid volume. ...
Aim:
The aim of this article was to obtain measurements of the eyeballs/globes and lacrimal glands in normal subjects using cranial computed tomography (CT) scan. Understanding the normative approximations of these measurements could help in diagnosing and evaluating orbito-ocular pathologies.
Materials and methods:
This retrospective study examined 220 globes/eyeballs and 220 lacrimal glands of 110 consecutive participants. The eyeball volume was calculated using both the ellipsoid and spherical formulas, whereas lacrimal gland volume was approximated using the ellipsoid formula only.
Results:
The mean age of the subjects was 51.18 ± 14.85 years and ranged from 22 to 85 years. The study population was 53.6% male (n = 59) and 46.3% female (n = 51). The mean volumes of all globes in this study were 5.82 ± 0.77 and 5.98 ± 0.75 cm3 using the ellipsoid and spherical formulae, respectively. The mean volume of all lacrimal glands was 0.42 ± 0.14 cm3 using the ellipsoid formula. The mean globe volumes using the ellipsoid and spherical formulae (6.02 ± 0.84 and 6.02 ± 0.84 cm3) in males were significantly larger than the corresponding mean globe volumes in females (5.59 ± 0.62 and 5.80 ± 0.65 cm3) (P < 0.0001 and P = 0.001, respectively). There was no significant difference between the lacrimal gland volumes of males (0.42 ± 0.14 cm3) and females (0.42 ± 0.14 cm3) (P = 0.84).
Conclusion:
Males have larger eyeball/globe volumes than females. Eyeball and lacrimal gland volumes did not correlate significantly. Eyeball volume showed an inverse relationship with age. Age did not affect lacrimal gland volume.
... Thirdly, females have a smaller skeletal system and a shorter reach distance than males, on average; thus, they may be required to adopt awkward postures more often, especially for con gurations that manipulate the position of digital devices [21]. Moreover, there has been some discussion of whether differences in bone mass result in greater skeletal integrity in males than females, making females more susceptible to injury [22]. ...
Background: Musculoskeletal pain (MSP) is frequent complaint among college students, especially neck and shoulder pain (NSP). No study so far has demonstrated a correlation between the use of digital devices and the prevalence of NSP among college students in China. Therefore, a cross-sectional survey investigating this relationship among college students in Shanghai was urgently needed.
Objective: The relationship between digital device usage, lifestyle, and the prevalence of self-reported NSP among college students in Shanghai, and neck muscle activity of different degrees of spinal curvature was investigated to provide suggestions for healthy spinal curvature lifestyle education.
Methods: 6000 students were randomly enrolled, and a self-reported questionnaire was conducted to assess the prevalence and severity of NSP. The students’ demographic characteristics, habits of using digital devices, and lifestyles were recorded. c² tests were used to compare the prevalence of NSP; univariable and multivariable logistic regression analyses were performed to identify potential risk factors for NSP. A musculoskeletal model of the standard human body was established with the AnyBody platform to test the neck muscle activity of different degrees of spinal curvature.
Results: Among the 4848 college students (80.8%) who completed the survey, the prevalence of NSP was 39.1%, with more girls (45.0%) reporting NSP than boys (32.4%). The logistic regression indicated that gender, inappropriate posture and using digital devices for long time had a significant correlation with NSP. Neck muscle activity increased as spinal inclination increased based on the AnyBody platform.
Conclusion: NSP seems to be a common condition among college students in Shanghai. Gender, inappropriate posture and using digital devices for long time are closely associated with NSP. The greater the anterior cervical and lumbar flexion, the higher the activity of cervical muscles. Healthy lifestyle education should be used to decrease the NSP among college students.
... Hastaların çoğu 80 yaşında olup %75 kadın hastalardır. Erkeklere kıyasla kadınlarda yaşla birlikte osteoporoz prevalansının artması ve kemik kütlesinin az olması bunun nedeni olabilir (5). Kadınlar, erkeklere kıyasla 2 ila 3 kat daha fazla etkilenmektedir (6). ...
Aim:Femoral neck fractures (FNF) occur in the intracapsular region of the proximal femur. The incidence of fractures in the proximal femur increases with age. FNF's cause high mortality and morbidity. Malnutrition is also one of the problems of these patients. In this study, it was aimed to reveal the importance of necessary nutritional follow-up in patients hospitalized in our hospital for FNF. Methods:XXXX Health Sciences University XXXXX Training and Research Hospital data of hospitalized patients with a diagnosis of FNF between 2017-2018 were retrospectively scanned from the patient file and the hospital automation system. 229 patients with a diagnosis of FNF were included in the study. Hospitalization diagnosis, age and gender, albumin, C-reactive protein (crp), and lymphocyte values of the patients were measured. The nutritional risk score (NRS-2002) made for each patient in the automation system of our hospital was checked. For nutritional support, it was checked whether a consultation was requested from the nutrition support team (NST). Results:The mean age of the patients included in the study was found to be 74 years. 79.3% were over 65 years old, while 20.97% were under 65. Albumin, lymphocyte and CRP values of the patients were examined and found that 65.1% albumin, 24.5% lymphocyte and 88.2% CRP values outside the normal range. There was a statistically significant negative correlation of 41% between the patients' albumin and age variable. (p
... The confounder candidates showed significant univariate associations with the outcomes and/or primary predictor and were therefore included as covariates in the final models. Sex stratification was used due to great discrepancy in skeletal size between men and women [28]. Beta estimates, their 95% confidence intervals (CIs), and the corresponding P values were extracted from the data output. ...
Background
Articular surface size is traditionally considered to be a relatively stable trait throughout adulthood. Increased joint size reduces bone and cartilage tissue strains. Although physical activity (PA) has a clear association with diaphyseal morphology, the association between PA and articular surface size is yet to be confirmed. This cross-sectional study aimed to clarify the role of moderate-to-vigorous PA (MVPA) in knee morphology in terms of tibiofemoral joint size.
Methods
A sample of 1508 individuals from the population-based Northern Finland Birth Cohort 1966 was used. At the age of 46, wrist-worn accelerometers were used to monitor MVPA (≥3.5 METs) during a period of two weeks, and knee radiographs were used to obtain three knee breadth measurements (femoral biepicondylar breadth, mediolateral breadth of femoral condyles, mediolateral breadth of the tibial plateau). The association between MVPA and knee breadth was analyzed using general linear models with adjustments for body mass index, smoking, education years, and accelerometer weartime.
Results
Of the sample, 54.8% were women. Most individuals were non-smokers (54.6%) and had 9—12 years of education (69.6%). Mean body mass index was 26.2 (standard deviation 4.3) kg/m ² . MVPA was uniformly associated with all three knee breadth measurements among both women and men. For each 60 minutes/day of MVPA, the knee breadth dimensions were 1.8—2.0% (or 1.26—1.42 mm) larger among women ( p < 0.001) and 1.4—1.6% (or 1.21—1.28 mm) larger among men ( p < 0.001).
Conclusions
Higher MVPA is associated with larger tibiofemoral joint size. Our findings indicate that MVPA could potentially increase knee dimensions through similar biomechanical mechanisms it affects diaphyseal morphology, thus offering a potential target in reducing tissue strains and preventing knee problems. Further studies are needed to confirm and investigate the association between articulation area and musculoskeletal health.
... Compared with men, women are smaller and lighter, and they have more body fat and lower skeletal muscle mass with shorter fiber lengths and cross-sectional areas (Haizlip et al., 2015;Trevino et al., 2019). In parallel, they have less bone mass and greater joint laxity (Nieves et al., 2005). All these factors mean not only lower force production and anaerobic capacity, but also a greater risk of bone fracture (Doherty et al., 2014;Wolf et al., 2015). ...
To achieve optimal sports performances, women and men may show specific doping practices because of the physiological and psychological gender differences, but there are few data on this topic. Here, we report the apparent use of prohibited substances and methods by female athletes based on analyses of the doping tests collected by the French Anti-Doping Agency from 2013 to 2019. We compared the frequency of use and the ergogenic and side effects to those of their male counterparts. The results revealed lower use of prohibited substances in female vs. male athletes, with significantly fewer anabolic agents, hormone and metabolic modulators, and cannabinoids. Gender specificity in utilization of substance classes was also shown. Relatively lower use of hormone modulators and cannabinoids and higher use of beta-2 agonists, diuretics and glucocorticoids were found in the woman cohort compared with men cohort, combined with the different choice of substances, possibly because of the altered ergogenic and/or side effects. However, no impact due to gender regarding the sports disciplines was observed, with both women and men showing similar use of anabolic agents, mainly in the anaerobic sports, and EPO and corticoids, mainly in endurance or mixed sports. Further studies are needed to put these French data into a global perspective, comparing uses across countries and exploring possible new developments in the fight against doping in women.
... The higher incidence in both female athletes and female military recruits might be partially explained by the association of bone stress injuries with low energy availability, a condition that is typically more prevalent in active women than in men. Sexual dimorphism in the adaptation of bone size relative to body size has also been proposed as a contributing factor 35,36 . The comparatively higher incidence in female military recruits than athletes might be influenced by sex neutral training loads (for example, pack weights during rucking) and overstriding during march training causing higher loads to be placed on the skeleton of female military recruits [37][38][39][40] . ...
Bone stress injuries, including stress fractures, are overuse injuries that lead to substantial morbidity in active individuals. These injuries occur when excessive repetitive loads are introduced to a generally normal skeleton. Although the precise mechanisms for bone stress injuries are not completely understood, the prevailing theory is that an imbalance in bone metabolism favours microdamage accumulation over its removal and replacement with new bone via targeted remodelling. Diagnosis is achieved by a combination of patient history and physical examination, with imaging used for confirmation. Management of bone stress injuries is guided by their location and consequent risk of healing complications. Bone stress injuries at low-risk sites typically heal with activity modification followed by progressive loading and return to activity. Additional treatment approaches include non-weight-bearing immobilization, medications or surgery, but these approaches are usually limited to managing bone stress injuries that occur at high-risk sites. A comprehensive strategy that integrates anatomical, biomechanical and biological risk factors has the potential to improve the understanding of these injuries and aid in their prevention and management. Bone stress injuries, commonly referred to as stress reactions or stress fractures, result from repeated overloading of bone and are thought to involve an imbalance in microdamage formation and repair. This Primer provides an overview of the epidemiology, pathobiology, risk factors, diagnostic approaches, treatments and consequences of bone stress injuries.
... A chi-square test was used to compare percentages significantly (0.05 and 0.01 probability) in this study [ 11 ]. This dramatic difference is expected due to a couple of reasons, firstly; females have smaller bones than men [ 12 ], secondly, females have the menopause, were they got accelerated amount of bone loss in early period of menopause, even men lose testosterone, but it's more gradual compared to menopause when women have dramatic declines in estrogen levels [ 13 ; 14 ]. ...
div>Rib fractures are associated with high rates of morbidity and mortality. Improved methods to assess rib bone quality are needed to identify at-risk populations. Quantitative computed tomography (QCT) can be used to calculate volumetric bone mineral density (vBMD) and bone mineral content (BMC), which may be related to rib fracture risk. The objective of this study was to determine if vBMD and BMC from QCT predict human rib structural properties. 127 mid-level (5th–7th) ribs were obtained from adult female ( n = 67) and male ( n = 60) postmortem human subjects (PMHS). Isolated rib QCT scans were performed to calculate vBMD and BMC. Each rib was subsequently tested to failure in a dynamic simulated frontal impact and structural properties, peak force ( F <sub>Peak</sub>), percent displacement ( δ <sub>Peak</sub>), linear structural stiffness ( K ), and total energy ( U <sub>Tot</sub>) were calculated. vBMD demonstrated no significant differences between sexes ( p > 0.05); however, males had a higher BMC than females ( p < 0.001). Further, sex-specific differences were observed in all rib structural properties except for δ <sub>Peak</sub> ( p > 0.05). Age had a significant relationship with both vBMD and BMC ( p < 0.001) but only in females when separated by sex ( p < 0.001). vBMD predicted F <sub>Peak</sub>, δ <sub>Peak</sub>, K , and U <sub>Tot</sub> ( R <sup>2</sup> = 9.2%–30.9%, p < 0.05) but was not able to predict δ <sub>Peak</sub> in males. Similarly, BMC also predicted all rib structural properties, except for δ <sub>Peak</sub> in males, but explained more meaningful amounts of variation ( R <sup>2</sup> = 22.2%–67.7%, p < 0.001). When predicting rib structural properties, BMC captures sex-specific variations in bone size that are obfuscated by vBMD and contribute to the biomechanical response of the rib during mechanical loading. Incorporating BMC into assessments of injury risk may therefore provide additional insight into the multifaceted nature of rib bone quality and differential fracture resistance.</div
The present study was designed to evaluate, the accurate relationship of the impacted third molar to the mandibular canal using cone beam computed tomography and its distance from cortical plates with its variation in relation to age, gender, side and angulation.
Materials and Methods: Three thirty four samples of cone beam computed tomography were identified. They were segregated according to different criterias say age, gender, side and angulation. The distance from the impacted tooth to the centre of mandibular third molar was measured. Also the distance between buccal and lingual cortical plates to the centre of the canal was measured. All the measurements were made with 3D CS software. Their variations with different criterias was identified.
Results: Statistical analysis was performed by using Karl Pearson correlation coefficient tests. The canal was most closely placed in case of females compared to males with respect to impacted tooth. Also the distance between the canal and tooth was less on the left side compared to the right side. There was no variation of the canal with age. But for angulation the distance was found to be more with horizontal and mesio angular impactions
Conclusion: The results of the present study shows that cone beam computed tomography is the best diagnostic tool to identify and locate the inferior alveolar canal in the mandible. The inferior alveolar canal has got a specific pattern of distribution which varies with side, age gender and angulations of impaction.
Purpose:
This 2-year longitudinal study examined the development of upper-extremity bone mineral density (BMD), bone mineral content (BMC), and lean mass (LM) asymmetry magnitudes in male and female youth tennis players.
Methods:
Dominant and nondominant upper-extremity BMD, BMC, and LM values of 49 male and 31 female players were measured yearly using dual X-ray absorptiometry. From these values, asymmetry magnitudes were calculated and expressed as a percentage. Maturity offset was estimated using anthropometric measurements. Linear mixed effect models examined the development of BMD, BMC, and LM asymmetry magnitudes according to players' maturity offset, sex, and training volume.
Results:
Adjusted for sex and training volume, a 1-year increment in maturity offset was associated with a significant increase in BMD (1.3% [2.2%]; P < .001) and BMC (0.6% [2.4%]; P = .011) asymmetry magnitudes. Male players displayed significantly higher LM asymmetry magnitudes (Δ3.2% [8.4%]; P = .002) compared with their female counterparts. Training volume was not significantly associated with asymmetry magnitude development.
Conclusion:
In contrast to LM, male and female youth tennis players' upper-extremity bones are still responsive to mechanical loading with a significant increase in BMD and BMC asymmetry magnitudes according to maturity offset.
Sex estimation from skeletal remains is one of the crucial issues in forensic anthropology. Long bones can be a valid alternative to skeletal remains for sex estimation when more dimorphic bones are absent or degraded, preventing any estimation from the first intention methods. The purpose of this study was to generate and compare classification models for sex estimation based on combined measurement of long bones using machine learning classifiers. Eighteen measurements from four long bones (radius, humerus, femur, and tibia) were taken from a total of 2141 individuals. Five machine learning methods were employed to predict the sex: a linear discriminant analysis (LDA), penalized logistic regression (PLR), random forest (RF), support vector machine (SVM), and artificial neural network (ANN). The different classification algorithms using all bones generated highly accuracy models with cross-validation, ranging from 90 to 92% on the validation sample. The classification with isolated bones ranked between 83.3 and 90.3% on the validation sample. In both cases, random forest stands out with the highest accuracy and seems to be the best model for our investigation. This study upholds the value of combined long bones for sex estimation and provides models that can be applied with high accuracy to different populations.
Introduction:
Mass deworming of preschool children is a strategy suggested to prevent soil-transmitted helminth infections in most developing countries. Nonetheless, there is a scarcity of data showing the contribution of mass deworming to a child's nutritional status. The purpose of this study was to assess the effect of deworming on nutritional health outcomes (stunting, underweight, and anemia) in children aged 12 to 59 months.
Methods:
A secondary analysis of data extracted from the Tanzania Demographic and Health Survey (TDHS) 2015-16 data was carried out. A total of 7,962 children were included in this study. A multilevel logistic regression was used at a 5% level of significance to determine the individual- and community-level determinants of deworming on health outcomes among children.
Results:
The prevalence of underweight (62.6%), stunting (61.0%), and anemia (61.8%) was higher in children who were not dewormed than those who were dewormed. Female children were more likely to suffer from poor health outcomes (OR = 1.01 and 95% CI = 0.95-1.07) than male children. Children aged 24-35 months and 36-47 months were significantly less likely to suffer from poor health outcomes (OR = 0.89; 95% CI = 0.82-0.97 and OR = 0.88; 96% CI = 0.81-0.96, respectively; p < 0.01). Children from households with unimproved toilets (OR = 1.38 and 95% CI = 1.25-1.52), unimproved water sources (OR = 1.08 and 95% CI = 1.01-1.16), and living in rural areas (OR = 1.02 and 95% CI = 0.91-1.14) had higher odds for poor health outcomes.
Conclusion:
Deworming may be an effective technique for preventing poor health outcomes in children and the risks associated with them, such as poor growth and development.
Sex-specific differences in bone integrity and properties are associated with age as well as the number and activity of cells involved in bone remodeling. The aim of this study was to investigate sex-specific differences in adhesion, proliferation, and differentiation of mouse bone marrow derived cells into osteoclasts. The adherent fraction of bone marrow- derived cells from 12-week-old male and female C57BL/6J mice were assessed for their adhesion, proliferation, and receptor activator of nuclear factor κB (RANKL)-induced differentiation into osteoclasts. Female bone marrow derived macrophages (BMDMs) displayed higher adhesion and proliferation ratio upon macrophage colony stimulating factor (M-CSF) (day 0) and M-CSF + RANKL (day 4) treatment, respectively. On the contrary, male BMDMs differentiated more efficiently into osteoclasts upon RANKL-treatment compared to females (day 5). To further understand these sex-specific differences at the gene expression level, BMDMs treated with M-CSF (day 0) and M-CSF + RANKL (day 4), were assessed for their differential expression of genes through RNA sequencing. M-CSF treatment resulted in 1106 differentially expressed genes, while RANKL-treatment gave 473 differentially expressed genes. Integrin, adhesion, and proliferation-associated genes were elevated in the M-CSF-treated female BMDMs. RANKL-treatment further enhanced the expression of the proliferation- associated genes, and of genes associated with inhibition of osteoclast differentiation in the females, while RANK-signaling-associated genes were upregulated in males. In conclusion, BMDM adhesion, proliferation and differentiation into osteoclasts are sex-specific and may be directed by the PI3K-Akt signaling pathway for proliferation, and the colony stimulating factor 1-receptor and the RANKLsignaling pathway for the differentiation.
Purpose:
Hip fractures in elderly have a high mortality. However, there is limited literature on the excess mortality seen in hip fractures compared to the normal population. The purpose of this study was to compare the mortality of hip fractures with that of age and gender matched Indian population.
Methods:
There are 283 patients with hip fractures aged above 50 years admitted at single centre prospectively enrolled in this study. Patients were followed for a year and follow-up was available for 279 patients. Mortality was assessed during the follow-up from chart review and/or by telephonic interview. One-year mortality of Indian population was obtained from public databases. Standardized mortality ratio (SMR) (observed mortality divided by expected mortality) was calculated. Kaplan-Meir analysis was used.
Results:
The overall 1-year mortality was 19.0% (53/279). Mortality increased with age (p < 0.001) and the highest mortality was seen in those above 80 years (aged 50-59 years: 5.0%; aged 60-69 years: 19.7%; aged 70-79 years: 15.8%, and aged over 80 years: 33.3%). Expected mortality of Indian population of similar age and gender profile was 3.7%, giving an SMR of 5.5. SMR for different age quintiles were: 3.9 (aged 50-59 years), 6.6 (aged 60-69 years), 2.2 (aged 70-79 years); and 2.0 (aged over 80 years). SMR in males and females were 5.7 and 5.3, respectively.
Conclusions:
Indian patients sustaining hip fractures were about 5 times more likely to die than the general population. Although mortality rates increased with age, the highest excess mortality was seen in relatively younger patients. Hip fracture mortality was even higher than that of myocardial infarction, breast cancer, and cervical cancer.
Background:
Background: Body mass index (BMI) is a risk factor for the type 2 diabetes (T2DM), and T2DM accompanies various complications, such as fractures. We investigated the effects of BMI and T2DM on fracture risk and analyzed whether the association varied with fracture locations.
Methods:
This study is a nationwide population-based cohort study that included all people with T2DM (n=2,746,078) who received the National Screening Program during 2009-2012. According to the anatomical location of the fracture, the incidence rate and hazard ratio (HR) were analyzed by dividing it into four categories: vertebra, hip, limbs, and total fracture.
Results:
The total fracture had higher HR in the underweight group (HR, 1.268; 95% CI, 1.228 to 1.309) and lower HR in the obese group (HR, 0.891; 95% CI, 0.882 to 0.901) and the morbidly obese group (HR, 0.873; 95% CI, 0.857 to 0.89), compared to reference (normal BMI group). Similar trends were observed for HR of vertebra fracture. The risk of hip fracture was most prominent, the risk of hip fracture increased in the underweight group (HR, 1.896; 95% CI, 1.178 to 2.021) and decreased in the obesity (HR, 0.643; 95% CI, 0.624 to 0.663) and morbidly obesity group (HR, 0.627; 95% CI, 0.591 to 0.665). Lastly, fracture risk was least affected by BMI for limbs.
Conclusion:
In T2DM patients, underweight tends to increase fracture risk, and overweight tends to lower fracture risk, but association between BMI and fracture risk varied depending on the affected bone lesions.
Sex estimation from human skeletal remains is of vital importance in the buildup of a biological profile of an
individual in medico-legal and bioarchaeological studies. The present study is focused on the estimation of sex from osteometric
measurements of the complete femur and its fragmentary parts, and the development of a web based application related to this. Fifteen
osteometric measurements were taken from 78 dry cadaveric femurs from the Faculty of Medicine, University of Kelaniya. Using R
software, linear discriminant analysis and logistic regression methods were applied to build classification models with the help of the
application of a stepwise procedure, to identify the best combination of measurements to estimate the sex of the femur. A cross-validation
method was applied to estimate the predictive accuracy of each model. Since the linear discriminant analysis model gave more predictive
accuracy than the regression model, we suggest using linear discriminant analysis to estimate the sex using osteometric measurements of
the femur. From the whole femur measurements, a formula to determine sex was developed with highest total accuracy of 83 % using
four parameters; epicondylar breadth, anteroposterior mid-shaft diameter, bi-trochanter length, and maximum shaft diameter. Similarly,
measurements of transverse head diameter and bi-trochanter length with a total accuracy of 76 % for the proximal part of the femur,
measurements of anteroposterior mid-shaft diameter with a total accuracy of 77 % for the mid-shaft, and measurements of epicondylar
breadth and maximum length of the lateral condyle with a total accuracy of 70 % for the distal part of the femur were identified as
significant discriminants to determine sex, and formulae were written accordingly. Average accuracy ranged from 83 % to 70 %, with
male accuracy slightly higher than that of females. A web application to estimate the sex of femur using these formulae was developed
and this will be of great importance for forensic medicine and bio-archaeological research in Sri Lanka.
While osteoporosis is more common in women, older men are at greater risk of mortality in hospital from fracture; they also have more osteoporosis‐associated complications. Risk assessment, screening and treatment are therefore important for men as well as women.
The absence of an established design load constitutes a challenge to the engineering design of classroom furniture. This study developed a methodology for estimating design loads for single user (SU) and multiple user (MU) wooden classroom chair and desk combinations offered to secondary school students in Ibadan, Oyo State, Nigeria. Service load distribution patterns for the chair and desk members in normal, backward and front-reclining sitting postures were determined for 15 girls and 15 boys using bathroom scales. A T-test was used to compare the significance of the means of the proportions of users’ weights transferred to the chair and the floor. Design loads were 1 kN (SU) and 2.7 kN (MU) for chair and desk configurations, respectively. Each SU and MU leg should be designed to support 35% and 40% of the service loads, respectively. Gender, sitting postures, and chair and desk designs influenced load distribution patterns significantly.
En el pasado, prácticamente no se le prestaba atención a todo lo relacionado ni con la ergonomía ni con el rendimiento de las mujeres ciclistas. El interés principal recaía en el ciclismo masculino, buscando mejoras ergonómicas que se tradujeran en un mejor confort y rendimiento. De hecho, no era habitual encontrar bicicletas específicas para mujeres, por lo que debían utilizar y adaptarse a las de los hombres. Esto suponía un gran inconveniente, porque las diferencias morfológicas y fisiológicas entre hombres y mujeres son evidentes y, consecuentemente, se requiere de un material específico y adaptado a cada sexo. Asimismo, la literatura científica sobre ciclismo femenino era y sigue siendo limitada.
Sin embargo, el crecimiento experimentado en los últimos años del ciclismo femenino, tanto en el número de practicantes como en el nivel de las mismas, así como la profesionalización de las ciclistas, ha favorecido que cada vez se le preste mayor atención. No obstante, aún queda camino por recorrer, puesto que las diferencias respecto al ciclismo masculino siguen siendo considerables.
Este capítulo se divide en dos partes. En primer lugar, se describirán aquellas características anatómicas y fisiológicas más destacables que diferencian a mujeres de hombres y que afectarán de forma clara a la ergonomía. Posteriormente, se focalizará el interés en el alto rendimiento y se describirán las características de rendimiento físico de las ciclistas de mayor nivel.
Both weight gain and weight loss in type 2 diabetic population were associated with increased risk of hip fracture, while maintaining weight lowered the risk of hip fracture. Regarding the risk of hip fracture, we can propose active monitoring to maintain the weight of type 2 diabetes patients.
Introduction:
In type 2 diabetes, patients are often asked to control their weight in order to reduce their diabetic morbidity. The American Diabetes Association recommends that diabetic patients conduct high-intensity interventions for regulating diet, physical activity, and behavior to reduce weight, followed by long-term comprehensive weight maintenance programs. Although such weight control attempts are required in diabetic patients, there are few studies on the effect of weight change on hip fracture in this population. We aim to investigate the association between body weight change and the incidence of hip fracture in subjects with type 2 diabetes using large-scale, nationwide cohort data on the Korean population.
Materials and methods:
A total of 1,447,579 subjects (894,204 men and 553,375 women) > 40 years of age, who were diagnosed with type 2 diabetes, were enrolled in this study. Weight change within 2 years was divided into five categories: from weight loss ≥ 10% to weight gain ≥ 10%. The hazard ratios (HRs) and 95% confidence intervals for the incidence of hip fracture were analyzed, compared with the reference of the stable weight group (weight change < 5%).
Results:
Among 5 weight change groups, more than 10% weight loss showed the highest HR (HR, 1.605; 95% CI, 1.493 to 1.725), followed by more than 10% weight gain (HR, 1.457; 95% CI, 1.318 to 1.612). The effect of weight change on hip fracture risk was greater in males than in females, and those under 65 years of age were greater than those over 65 years of age. Baseline BMI did not play a role of weight change affecting the risk of hip fracture. The HR for hip fracture of subjects with regular exercise was lower than those without regular exercise.
Conclusions:
In the type 2 diabetes population, both weight gain and weight loss were significantly associated with a higher risk of hip fracture, whereas maintaining body weight reduced the risk of hip fracture the most.
Purpose: Osteoporosis is an under-diagnosed chronic disease, posing a significant
healthcare burden globally. Screening using abdominal CT can identify patients with
low bone mineral density (BMD) at greater fracture risk. We assessed the utility of
osteoporosis screening, using dual-energy X-ray absorptiometry (DXA) T-scores
as reference.
Method: Patients 30 years or older undergoing abdominal CT and DXA within 12
months were retrospectively assessed. BMD was measured using axial CT attenuation
in HU at L1, correlating with DXA T-scores. Sensitivity, specificity, area under the curve
(AUC) and odds ratio (OR) were calculated.
Results: 407 CT-DXA pairs were included (58.2% females). The prevalence of
osteoporosis was 11.8%. L1 density and T-score were significantly correlated in both
females (r = 0.35, p < 0.001) and males (r = 0.15, p = 0.04). The AUC to distinguish
osteoporosis from osteopenia and normal BMD was 0.64 (95% CI: 0.56 - 0.71). In
females, a threshold of 190 HU detected T-scores ≤ -2.5 with a NPV of 94.4% (OR =
4.4, p < 0.01). In the entire cohort, a threshold of 180 HU detected T-scores ≤ -2.5 with
a NPV of 96.2% (OR = 4.7, p < 0.01).
Conclusions: CT L1 attenuation correlates with L1 DXA T-scores. Density values less
than 190 HU and 180 HU increased the probability of osteoporosis diagnosis in an
Australian female and overall cohort, respectively. Opportunistic screening for
osteoporosis using abdominal CT is feasible, enabling identification of at-risk subjects
for formal DXA imaging, thereby improving treatment initiation and reducing fracture
risk.
Osteoporosis in men is a common but often overlooked disorder by clinicians. The criterion for osteoporosis diagnosis in men is similar to that in women-namely, a bone mineral density (BMD) that is 2·5 standard deviations or more below the mean for the young adult population (aged 20-29 years; T-score -2·5 or lower), measured at the hip or lumbar spine. Sex steroids are important for bone health in men and, as in women, oestrogens have a key role. Most men generally have bigger and stronger bones than women and typically have less bone loss during their lifetime. Men typically fracture less often than women, although they have a higher mortality rate after a fracture. Secondary osteoporosis is more common in men than in women. Lifestyle changes, adequate calcium, vitamin D intake, and exercise programmes are recommended for the management of osteoporosis in men. Bisphosphonates, denosumab, and teriparatide have been shown to increase BMD and are used for pharmacological treatment. In this Review, we report an updated overview of osteoporosis in men, describe new treatments and concepts, and discuss persistent controversies in the area.
L’ostéoporose est caractérisée par une diminution de la masse et de la résistance osseuses. La sarcopénie est une perte de la masse et de la force musculaires. Ces deux pathologies augmentent le risque de fracture ensemble et indépendamment l'une de l'autre. Leur association, « ostéo-sarcopénie », se caractérise par un risque de fracture disproportionné, ce qui suggère une interaction entre elles. L'adaptation de l'os à la charge mécanique est médiée par la contrainte ce qui est expliqué en partie par la théorie du « mécanostat ». Nous avons montré précédemment qu’une force de préhension faible est associée à un déclin accéléré de la microarchitecture osseuse au niveau du radius distal (Wagner, J Bone Miner Res, 2018). Une mobilité réduite est un facteur de risque de chute et de fracture. Une mauvaise performance physique peut donc contribuer au risque de fracture par le biais d'une perte rapide de la résistance osseuse et par l’accroissement du risque de chute. Les données prospectives sur les facteurs de risque du déclin de la performance physique des membres inférieurs sont limitées et insuffisamment contrôlées pour les facteurs de confusion et les interactions entre eux. L'impact d'un facteur (par ex. une faible activité physique) peut être plus fort si un autre facteur (par ex. l'obésité ou une comorbidité) est présent. Les données disponibles doivent donc être interprétées avec précaution. Chez 821 hommes âgés de 60 à 87 ans de la cohorte STRAMBO, la performance physique a été évaluée cliniquement par : les levés de chaise répétés, l’équilibre statique avec les yeux fermés, la marche en funambule en avant et en arrière. Le score global était calculé sur la base de la capacité à réaliser le test (O/N) et du temps nécessaire pour le faire. La densité minérale osseuse et la composition corporelle étaient évaluées par ostéodensitométrie à rayons X. Au niveau du tibia distal La microarchitecture osseuse a été évaluée par microtomodensitométrie périphérique (XtremeCT Scanco). Les chutes et les fractures ont été recueillies annuellement pendant 8 ans. Les tests cliniques ont été répétés après 4 et 8 ans. Ce travail de thèse porte sur deux articles. Le premier montre qu’une faible performance physique des membres inférieurs est associée à un déclin accéléré de la microarchitecture osseuse et de la résistance mécanique estimée par l’analyse à éléments finis au niveau du tibia distal. Après ajustement pour les facteurs confondants, une performance physique faible est associée à un risque élevé de chute suivie d’une hospitalisation (HR=2,60, ICà95% : 1,56–4,34, p<0,01) et de fracture non-vertébrale (HR=2,68, ICà95% : 1,08–6,66, p<0,05). Le second article montre qu’une obésité sarcopénique (masse musculaire basse, masse adipeuse accrue) est associée à un risque accru de baisse incidente de la performance physique des membres inférieurs après ajustement pour les facteurs confondants. L’obésité sarcopénique est associée à un risque élevé de perte de la capacité à réaliser la marche en funambule en avant (OR=3,31 ICà95% : 1,88–5,84, p<0,001) et en arrière ainsi qu’à un risque élevé d’incapacité à réaliser plusieurs tests (OR=5.82, ICà95% : 1,29–26,27, p<0.001). Nos résultats montrent l’importance de la performance physique des membres inférieurs pour la microarchitecture osseuse du tibia et pour le risque de chute et de fracture. Une intervention pourrait limiter ces risques. L’obésité sarcopénique est associée à un risque accru de perte de la performance physique chez les sujets valides. Une intervention dans ce groupe pourrait prévenir la perte de performance physique et ses séquelles potentielles. Les futures études devraient être focalisées sur les trois axes : Confirmer nos résultats dans d’autres cohortes ; Étudier d’autres facteurs de risque de perte de la performance physique ; Définir les moyens de rééducation permettant de prévenir la perte de la performance physique chez les sujets atteints d’une obésité sarcopénique.
Sex steroids regulate bone metabolism in young men during growth and consolidation. Their deficit during growth compromises longitudinal and radial growth of bones and has a negative impact on body height, bone width, peak areal bone mineral density (aBMD) and bone microarchitecture. In older men, the deficit of sex steroid hormones (mainly 17β-oestradiol) contributes to high bone turnover rate, low aBMD, poor bone microarchitecture, low estimated bone strength, accelerated bone loss and rapid decline of bone microarchitecture. The role of 17β-oestradiol is confirmed by the case of men with congenital estrogen receptor deficit and with congenital aromatase deficiency. 17β-oestradiol inhibits bone resoption, whereas both hormones regulate bone formation. However, the associations are weak. Prospective data on the utility of blood 17β-oestradiol or testosterone for fracture risk assessment are inconsistent. Men with hypogonadism have decreased aBMD and poor bone microarchitecture. In men with hypogonadism, testosterone replacement therapy increases aBMD and improves bone microarchitecture. In men with prostate cancer, androgen deprivation therapy (gonadoliberin analogues) induces rapid bone loss and severe deterioration of bone microarchitecture.
The prevalence of osteoporosis and the incidence of fractures are substantially lower in black than in white subjects, a finding generally attributed to racial differences in adult bone mass. Whether these racial differences are present in childhood is the subject of considerable interest, as the amount of bone gained during growth is a major determinant of future susceptibility to fractures. We measured the density and size of the vertebrae and femurs of 80 black and 80 white healthy children, 8-18 yr of age, matched for age, gender, height, weight, and stage of sexual development, using computed tomography. Race had a significant and differential effect on the bones in the axial and appendicular skeletons. In the axial skeleton, black children had greater cancellous bone density, but similar cross-sectional area of the vertebral bodies. In contrast, in the appendicular skeleton, black children had greater femoral cross-sectional area, but similar cortical bone area and cortical bone density. Compared to white children, vertebral bone density and femoral cross-sectional area at sexual maturity were, on the average, 10.75% and 5.7% higher, respectively, in black children. Such significant variations may contribute to the racial differences in the prevalence of osteoporosis between black and white adults.
The aim was to describe the population based age and sex specific incidence of fractures at different sites in a large English health district.
Recording of fractures was accomplished by a specially constructed outpatient index and by record linkage to hospital inpatient information, for the three years surrounding the 1981 census.
The fracture index was held by the Department of Community Health in Leicester using data from the fracture clinic at the central large district general hospital, supplemented by hospital inpatient data from Trent Region and the two adjoining regions.
The denominator population was the Leicestershire Health Authority resident population. In the three years, 12,711 fractures amongst males and 10,565 amongst females were recorded.
The overall estimated annual incidence of fractures was 100 per 10,000 population for males and 81 per 10,000 population for females. Below the age of 55 years all fractures showed a higher incidence amongst males but amongst the over 55s, there was a consistent fall in the male:female incidence ratio with some sites showing a striking female preponderance. The results also show an apparent age specific temporal increase in incidence at certain fracture sites compared with earlier British data, but fracture incidence figures still suggest lower rates in this country than in North America and some Scandinavian countries.
These findings provide population based incidence data on a major public health problem and are consistent with the major determinants of osteoporosis and increase in falls in postmenopausal women. The temporal and geographical variation in fracture incidence remain to be explained.
To determine if vertebral bone densities or vertebral body sizes contribute to gender differences in vertebral bone mass in adults.
Cancellous and cortical bone densities and dimensions of three lumbar vertebrae in 25 women and 18 men were measured with quantitative computed tomography (CT) and statistically analyzed.
Neither cancellous nor cortical vertebral bone densities differed in healthy adults. Vertebral bodies in women had lower cross-sectional areas (8.22 cm2 +/- 1.09 [standard deviation] versus 10.98 cm2 +/- 1.25, P < .001) and volumes (22.42 cm3 +/- 2.40 versus 30.86 cm3 +/- 2.6, P < .001). These differences also were evident in men and women matched for age, weight, vertebral bone density, and vertebral body height. Overall cross-sectional areas of vertebral bodies are 25% smaller in women than men. Vertebral bone densities do not differ between sexes. Estimates of mechanical stress within vertebral bodies are 30%-40% higher in women than men for equivalent applied loads.
Smaller vertebral bodies in women confer biomechanical disadvantages that may contribute to more vertebral fractures in elderly women.
To determine whether differences in vertebral bone densities or sizes account for gender differences in skeletal mass during growth.
Quantitative computed tomography (CT) was used to measure the densities of cortical and cancellous bone and dimensions of the lumbar vertebral bodies in 196 healthy children and adolescents, ages 4-20 years.
Neither cancellous nor cortical bone densities differed between boys and girls with age or level of sexual development. In contrast, the cross-sectional areas of the vertebral bodies were greater in boys than girls throughout childhood and adolescence. Even when prepubertal children were matched for chronologic age, bone age, height, and weight, the size of the vertebral bodies was 17% greater in boys. This disparity in vertebral body size increased with level of sexual development and was greatest at sexual maturity.
Lower vertebral bone mass of women as compared with men may result from early gender differences in the sizes of bones rather than differences in bone densities.
The limbs of growing chicks (2-12 wk of age) were subjected to differing conditions of mechanical use to examine the effect of extrinsic loading on bone modeling early in postnatal growth. One group of chicks was subjected to intensive exercise by running on a treadmill 5 days/wk at 60% maximum speed while carrying on their trunk a load equal to 20% of body weight (EXER). In a second group, weight-bearing function was eliminated by sciatic denervation of one hindlimb at 2 wk of age (DNV). A third group grew under sedentary conditions (SED). Comparisons among groups were made on the basis of bone mass and length, cortical cross-sectional area and second moment of area, cortical thickness, longitudinal curvature, and % ash. After normalizing for growth-related differences in body mass among the three groups, we found that exercise led to an overall 16 +/- 13% increase in cortical cross-sectional area and a 26 +/- 21% increase in second moment of area measured at proximal, midshaft, and distal levels of the bone compared with values of SED animals. These increases in cortical geometry corresponded to a 10% increase in total bone mass and were generally established by 8 wk of age (6 wk of training) and maintained to 12 wk of age. When deprived of functional use, the growing bones of DNV animals were reduced in mass (-19%), cortical area (-8 +/- 7%), and second moment of area (-11 +/- 9%) compared with SED animals. DNV tibiotarsi were also significantly shorter (7% at 8 wk and 14% at 12 wk); however, the contralateral load-bearing tibiotarsus of the DNV animals was similarly reduced compared with SED and EXER animals, suggesting a general reduction of growth in the DNV group. Even more pronounced than the reductions in bone mass and area, however, were the loss of normal longitudinal curvature and an increase in the variability of cross-sectional shape and cortical thickness of the DNV tibiotarsi compared with SED and EXER animals.
Recent observations suggest that throughout life the size of the vertebral bodies in females is smaller than that in males even after accounting for differences in body size. To confirm these reports and to determine whether similar differences exist in the appendicular skeleton, detailed measurements of the sizes of the vertebrae and the femur were obtained using computed tomography in 30 pairs of prepubertal boys and girls matched for age, height, and weight. Anthropometric parameters as well as gender influenced the cross-sectional area of the vertebrae. Heavier children had greater vertebral cross-sectional area than slender children regardless of gender, and the vertebral bodies were found to be significantly smaller in girls than in matched boys (approximately 11%), both using Student's t test (P < 0.0001) and its multivariate analog, the Hotelling's T2 test (P < 0.0001). In contrast to these findings in the axial skeleton, gender status did not influence the size of the bones in the appendicular skeleton, and neither the cross-sectional area (3.28 +/- 0.84 vs. 3.10 +/- 0.56 cm2) nor the cortical bone area (1.80 +/- 0.37 vs. 1.85 +/- 0.36 cm2) at the midshaft of the femur differed between boys and girls. These values, however, correlated strongly with all anthropometric indexes, and multiple regression analyses indicated that both measurements were primarily related to weight. The results suggest that although increases in mechanical loading associated with growth are the main determinant of the cross-sectional properties of the appendicular skeleton in children, factors other than body mass and related to gender have a significant role in the regulation of the sizes of the bones in the axial skeleton.
A total of 626 U.S. male Marine Corps recruits underwent anthropometric measurements and dual-energy X-ray absorptiometry (DXA) scans of the femoral midshaft and the distal third of the tibia prior to a 12 week physical training program. Conventionally obtained frontal plane DXA scan data were used to measure the bone mineral density (BMD) as well as to derive the cross-sectional area, moment of inertia, section modulus, and bone width in the femur, tibia, and fibula. During training, 23 recruits (3.7%) presented with a total of 27 radiologically confirmed stress fractures in various locations in the lower extremity. After excluding 16 cases of shin splints, periostitis, and other stress reactions that did not meet fracture definition criteria, we compared anthropometric and bone structural geometry measurements between fracture cases and the remaining 587 normals. There was no significant difference in age (p = 0.8), femur length (p = 0.2), pelvic width (p = 0.08), and knee width at the femoral condyles (p = 0.06), but fracture cases were shorter (p = 0.01), lighter (p = 0.0006), and smaller in most anthropometric girth dimensions (p < 0.04). Fracture case bone cross-sectional areas (p < 0.001), moments of inertia (p < 0.001), section moduli (p < 0.001), and widths (p < 0.001) as well as BMD (p < 0.03) were significantly smaller in the tibia and femur. After correcting for body weight differences, the tibia cross-sectional area (p = 0.03), section modulus (p = 0.05), and width (p = 0.03) remained significantly smaller in fracture subjects. We conclude that both small body weight and small diaphyseal dimensions relative to body weight are factors predisposing to the development of stress fractures in this population. These results suggest that bone structural geometry measurements derived from DXA data may provide a simple noninvasive methodology for assessing the risk of stress fracture.
Dual-energy x-ray absorptiometry (DEXA) is a rapid and precise technique for the assessment of bone mineralization in children. Interpretation of the results in growing children is complex as results are influenced by age, body size (height and weight) and puberty. Conventionally, bone mineral data derived from DEXA have been presented as an areal density [BMD; bone mineral content (BMC, g)/projected bone area (BA, cm²)], yet this fails to account for changes in BMC that result from changes in age, body size or pubertal development. Measurement of BMC and BA of the whole body, lumbar spine and left hip were made in 58 healthy boys and girls using DEXA. The relationship between BMC and BA was curvilinear, with the best fit being that of a power model (BMD = BMC/BAᵝ, where β is the exponent to which BA is raised in order to remove its influence on BMC). The value of β changed when measures of body size and puberty were taken into account (e.g. for lumbar spine from 1.66 to 1.49). Predictive formulae for BMC were produced using regression analysis and based on the variables of age, body size and pubertal development. This provides a method for interpreting the measured BMC which is independent of such variables and a constant reference range for children aged 6-18 y.
The prevalence of osteoporosis and the incidence of fractures are substantially lower in black than in white subjects, a finding generally attributed to racial differences in adult bone mass. Whether these racial differences are present in childhood is the subject of considerable interest, as the amount of bone gained during growth is a major determinant of future susceptibility to fractures. We measured the density and size of the vertebrae and femurs of 80 black and 80 white healthy children, 8-18 yr of age, matched for age, gender, height, weight, and stage of sexual development, using computed tomography. Race had a significant and differential effect on the bones in the axial and appendicular skeletons. In the axial skeleton, black children had greater cancellous bone density, but similar cross-sectional area of the vertebral bodies. In contrast, in the appendicular skeleton, black children had greater femoral cross-sectional area, but similar cortical bone area and cortical bone density. Compared to white children, vertebral bone density and femoral cross-sectional area at sexual maturity were, on the average, 10.75% and 5.7% higher, respectively, in black children. Such significant variations may contribute to the racial differences in the prevalence of osteoporosis between black and white adults.
Body weight impacts on both bone turnover and bone density, and is therefore an important risk factor for vertebral and hip fractures, ranking in importance alongside that of age. The effect of body weight is probably contributed to by both fat mass and lean mass, although in postmenopausal women fat mass has been more consistently demonstrated to be important. A number of mechanisms for the fat-bone relationship exist and include the effect of soft tissue mass on skeletal loading, the association of fat mass with the secretion of bone-active hormones from the pancreatic β cell (including insulin, amylin, and preptin), and the secretion of bone-active hormones (e.g., estrogens and leptin) from the adipocyte. These factors alone probably do not fully explain the observed clinical associations, and further study of the actions on bone of novel hormones related to nutrition is an important area of further research. An understanding of this aspect of bone biology may open the way for new treatments of osteoporosis. More immediately, the role of weight maintenance in the prevention of osteoporosis is an important public health message that needs to be more widely appreciated.
Mullerian agenesis, a congenital malformation of the genital tract is the second most common cause of primary amenorrhea. Its etiology is poorly understood but it may be associated with renal, skeletal, and other abnormalities. The diagnosis is often made either radiologically or laparoscopically in patients in whom hormonal and karyotypic investigations for primary amenorrhea are normal, Two-dimensional ultrasound is not a reliable method of diagnosis, as exemplified by the two cases presented in this review; however, three-dimensional ultrasound may be a more sensitive diagnostic tool. The management is varied, but we conclude that the treatment of choice should be a nonsurgical approach aimed at creating a neovagina, Because of the implications for reproduction, these patients require psychological support, which should be offered as part of therapy. Target audience: Gynecologists and Family Physicians Learning objectives: After completion of this article, the reader will be able to describe the pathophysiology and clinical presentation of mullerian agenesis and to list the other abnormalities associated with this condition and to outline potential treatment options for a patient with mullerian agenesis.
The roles of androgen and estrogen in pubertal growth, epiphyseal maturation, and accretion of bone mass have generally been perceived to be overlapping. Described in this article are three recently published novel case reports that reveal important new concepts regarding the relative roles of these two classes of hormones. A woman and a man with aromatase deficiency and a man with estrogen resistance secondary to an estrogen-receptor mutation are described. The details of their phenotypes reveal that although androgens have direct growth-stimulating actions on the epiphysis, the final phase of skeletal maturation associated with epiphyseal closure seems to be primarily an estrogen-dependent phenomenon in men and women. In addition, bone mass accrued during puberty is primarily induced by estrogen in both sexes.
(C) Lippincott-Raven Publishers.
The interrelationships between measurements of bone mass and total-body bone mineral were examined in a cross-sectional study of normal healthy women aged 17–82 years. In addition we evaluated the relationship between measures of body composition, estimated by four independent techniques, and bone mass in the same population. Considering the group as a whole, bone mass at all sites correlated with each other and with total-body bone mineral (TBBM). Cancellous and cortical sites could predict TBBM equally well. As expected, all measurements of bone mass were significantly lower in postmenopausal women in comparison to premenopausal women. Declines in bone mass were only seen in premenopausal women in the femoral neck and Ward's triangle, not in lumbar spine, radius, or skeleton as a whole. In postmenopausal women bone mass correlated negatively with age and years from menopause equally at all sites. TBBM was significantly related to height and weight in both premenopausal and postmenopausal women. In premenopausal and postmenopausal women TBBM also correlated with fat mass, but TBBM was much better correlated with percentage body fat in premenopausal than postmenopausal women. TBBM was a constant proportion of lean body mass in premenopausal women, but the fraction of lean mass occupied by the skeleton declined with age in postmenopausal women. Correction of TBBM for lean mass did not change the relationship between TBBM and percentage fat in premenopausal women but eliminated the relationship in postmenopausal women. Regional measurements, which are at least partially corrected for body size by dividing mass by area, correlated less well with height and weight and with any index of obesity, especially in postmenopausal women.
Spine fractures usually occur less commonly in men than in women. To identify the structural basis for this gender difference in vertebral fragility, we studied 1013 healthy subjects (327 men and 686 women) and 76 patients with spine fractures (26 men and 50 women). Bone mineral content (BMC), cross-sectional area (CSA), and volumetric bone mineral density (vBMD) of the third lumbar vertebral body (L3) were measured by posteroanterior (PA) and lateral scanning using dual-energy X-ray absorptiometry (DXA). In this cross-sectional study, the diminution in peak vertebral body BMC from young adulthood to old age was less in men than in women (6% vs. 27%). This diminution was the net result of two opposing changes occurring concurrently throughout adult life: the removal of bone adjacent to marrow on the inner (endosteal) surface by bone resorption and the deposition of bone on the outer (periosteal) surface by bone formation. For L3, we estimated that men resorbed 3.7 g and deposited 3.1 g, producing a net loss of 0.6 g from young adulthood to old age and women resorbed 3.1 g and deposited only 1.2 g, producing a net loss of 1.9 g. Thus, based on our indirect estimates of periosteal gain and endosteal loss across life, the observed net diminution in BMC during aging was less in men than women because absolute periosteal bone formation was greater in men than women (3.1 g vs. 1.2 g) not because absolute bone resorption was less in men. On the contrary, the absolute amount of bone resorbed was greater in men than women (3.7 g vs. 3.1 g). Periosteal bone formation also increased vertebral body CSA 3-fold more in men than in women, distributing loads onto a larger CSA, so that the load imposed per unit CSA decreased twice as much in men than in women (13% vs. 5%). In men and women with spine fractures, CSA and vBMD were reduced relative to age-matched controls. However, vBMD was no different to the adjusted vBMD in age-matched controls derived assuming controls had no periosteal bone formation during aging. Thus, large amounts of bone are resorbed in men as well as in women, accounting for the age-related increase in spine fractures in both genders. Periosteal bone formation increases CSA and offsets bone loss in both genders but more greatly in men, accounting for the lower incidence of spine fractures in men than in women. We speculate that reduced periosteal bone formation, during growth or aging, may be in part responsible for both reduced vertebral size and reduced vBMD in men and women with spine fractures. Sexual dimorphism in vertebral fragility is more the result of gender differences in age-related bone gain than age-related bone loss.
Hip scans of U.S. adults aged 20–99 years acquired in the Third National Health and Nutrition Examination Survey (NHANES III) using dual-energy X-ray absorptiometry (DXA) were analyzed with a structural analysis program. The program analyzes narrow (3 mm wide) regions at specific locations across the proximal femur to measure bone mineral density (BMD) as well as cross-sectional areas (CSAs), cross-sectional moments of inertia (CSMI), section moduli, subperiosteal widths, and estimated mean cortical thickness. Measurements are reported here on a non-Hispanic white subgroup of 2719 men and 2904 women for a cortical region across the proximal shaft 2 cm distal to the lesser trochanter and a mixed cortical/trabecular region across the narrowest point of the femoral neck. Apparent age trends in BMD and section modulus were studied for both regions by sex after correction for body weight. The BMD decline with age in the narrow neck was similar to that seen in the Hologic neck region; BMD in the shaft also declined, although at a slower rate. A different pattern was seen for section modulus; furthermore, this pattern depended on sex. Specifically, the section modulus at both the narrow neck and the shaft regions remains nearly constant until the fifth decade in females and then declined at a slower rate than BMD. In males, the narrow neck section modulus declined modestly until the fifth decade and then remained nearly constant whereas the shaft section modulus was static until the fifth decade and then increased steadily. The apparent mechanism for the discord between BMD and section modulus is a linear expansion in subperiosteal diameter in both sexes and in both regions, which tends to mechanically offset net loss of medullary bone mass. These results suggest that aging loss of bone mass in the hip does not necessarily mean reduced mechanical strength. Femoral neck section moduli in the elderly are on the average within 14% of young values in females and within 6% in males.
This population-based study revealed that 2,519 limb fractures occurring during a 3-year period produced an age-adjusted incidence rate for all limb fractures of 1,596 per 100,000 person-years. Fractures of the upper limb had a bimodal age distribution and were commoner than those of the lower limb, which had a J-shaped age distribution. The most frequent anatomic site was the lower end of the radius and ulna. Limb fractures occurred as solitary events in 93% of cases; only 4% were classified as open and more than half of the total were closed and undisplaced. Fractures were distributed evenly throughout all time periods of the day. The commonest place of fracture occurrence was the home, and the most important direct cause was falls, particularly in females. A wide range of sports activities were a major source of fractures, particularly in younger males. Underlying bone pathology was uncommon, other contributory causes being more important, particularly in the elderly. The increased ratio of metaphyseal to diaphyseal fractures with age indicated a relative loss of cancellous bone in the elderly, but no evidence was found to suggest that elderly women had reduced resistance of bone to impact forces in comparison with elderly men.
A cross-sectional study of 222 healthy Finnish men aged 20-69 years was performed to establish reference values of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA). The effects of age, and of some physical and lifestyle factors on BMD of the lumbar spine and proximal femur (femoral neck, Ward's triangle and trochanter) were investigated. The maximal mean BMD was observed at the age of 20-29 years in all the measurement sites. Except for the trochanteric area, BMD diminished along with age, the over-all decrements being 4%, 11%, and 23% in the lumbar, femoral neck and Ward's triangle areas, respectively. BMD was in a positive relationship to weight and height in all the measurement sites. The adjusted (for age, height and weight) BMDs were higher (P less than 0.05) in the group of daily dietary calcium intake greater than 1200 mg as compared with the group of lowest calcium intake (less than 800 mg day-1) in the three femoral areas. Cigarette smoking or alcohol drinking had no obvious effect on BMD.
Avian embryos can be completely paralyzed by injection of neuromuscular-blocking agents. We used a single injection of decamethonium iodide to paralyze embryos at 7, 8, or 10 days of incubation and analyzed the growth of individual bones (clavicle, mandible, ulna, femur, tibia, humerus) and of individual muscles that act upon some of those bones (clavicular and sternal heads of m. pectoralis, and mm. biceps brachii, depressor mandibulae, pseudotemporalis, and adductor externus). Growth of the bones is not equally affected by paralysis. Only 27% of clavicular growth (by mass) but 77% of mandibular growth occurred in paralyzed embryos, whereas the four long bones exhibited 52-63% of their normal growth. Analysis of muscle weight, fiber length and physiological cross-sectional area (weight/fiber length) indicate that there was greater reduction of the muscles acting on the limbs than of those acting on the mandible, i.e., diminished growth of the skeleton is correlated with reduced muscular activity. Specific retardation of clavicular growth is due to fusion of sternal rudiments and collapse of the thorax, as well as virtual absence of the musculature that normally attaches to the clavicle. We discuss these results in the light of intrinsic and extrinsic factors governing growth of the embryonic skeleton. Paralysis reduces skeletal growth by reducing both the movements taking place in ovo, and the loads imposed on the bones by muscle contraction, changes that represent alterations in the mechanical environment of the skeleton.
Osteoporotic fractures are more common in women than men. Although accelerated bone loss following the menopause is recognized as of major importance, it is generally considered that a lower peak adult bone mass in females also contributes to their increased risk of osteoporosis in later life. To examine potential sex differences in peak adult bone mass we studied 29 pairs of dizygotic twins of differing within-pair sex in whom the female twin was premenopausal (mean age 37 years, range 21-55). Bone mineral density (BMD, g/cm2) was measured at the lumbar spine and femoral neck by dual-photon absorptiometry; 22 pairs also had BMD measured in the distal and 21 pairs in the ultradistal radius by single-photon absorptiometry. There was no significant difference in usual dietary calcium intake or tobacco consumption between the twin pairs. Consistent with accepted dogma, BMD at both radial sites were higher (+27%) in the males than their female cotwins. In contrast, there was no sex difference (male versus female) in BMD (mean +/- SEM) in the femoral neck (0.96 +/- 0.02 versus 0.97 +/- 0.03), and surprisingly, the females had a greater lumbar spine BMD than their male cotwins (1.19 +/- 0.03 versus 1.26 +/- 0.03, p less than 0.05). This difference was observed despite the fact that the males were taller (p = 0.033). If the femoral neck BMD values in the females were corrected for this difference in BMI, their values (0.99 +/- 0.03 g/cm2) were significantly higher than those in their male cotwin (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Size, ash-density and biomechanical competence were investigated on whole vertebral bodies (L2) from 90 normal individuals (47 males and 43 females), aged 15-91 years. At all ages, cross-sectional area was significantly greater in males than in females. Furthermore, in males a significant increase of 25-30% in cross-sectional area was demonstrated with aging (r = 0.33, p less than 0.05). Conversely, no age-related change in cross-sectional area was detected in females (r = 0.03, n.s.). A significant and identical age-related decrease (p less than 0.001) in apparent ash-density was found for both males and females. Biomechanical compression tests revealed significant and identical decreases (p less than 0.001) in vertebral body load and stress with age in both males and females. However, because of their greater cross-sectional area and an increase in this with age, the level for the load-values was higher in men than in women up to the age of 75 years (p less than 0.05). The present study has demonstrated that in men there is a significantly greater cross-sectional area and a significant increase in vertebral body size, due to continuous periosteal growth. This could, to some extent, compensate for the unavoidable loss of vertebral bone density and stress with age. No age-related compensatory mechanism could be demonstrated in women.
This study used Rana pipiens tadpoles to assess the effect of complete and partial sciatic denervation on tibial bone growth and foot growth. Complete sciatic denervation was performed in R. pipiens at Stages XIV, XVII, and XX and they were killed at Stages XVII, XX, and XXIV. Partial denervation consisted of peroneal or tibial nerve sectioning at Stages XVII and XX with killing at Stages XX and XXIV. Analysis of experimental animals and controls consisted of (a) quantitative axon counts, (b) tibial length, (c) midtibial cross-sectional area, (d) midtibial cortical thickness, (e) midtibial cartilage anlage cross-sectional area, (f) foot silhouette area, and (g) osteocyte number and osteocyte density. Both complete and partial denervation resulted in significant effects on bone and foot growth: (a) decreased bone length, (b) decreased cross-sectional bone area without cortical thinning, (c) increased cartilage anlage cross-sectional area, and (d) decreased foot size. This experiment demonstrated a trophic effect of nerve on bone growth and development and foot growth. The mechanism of this action is unknown but the data suggests a slowed rate of maturation in denervated bones. The possibility exists that defective peripheral nerve-limb tissue interactions may cause human deformities such as idiopathic clubfoot and idiopathic limb length discrepancy.