[Show abstract][Hide abstract] ABSTRACT: Our purpose was to identify factors for a parsimonious fracture risk assessment model considering morphometric spine fracture status, femoral neck bone mineral density (BMD) and the World Health Organization (WHO) clinical risk factors. Using data from 2761 subjects from the Canadian Multicentre Osteoporosis Study (CaMos), a prospective, longitudinal cohort study of randomly selected community-dwelling men and women aged ⩾50 years, we previously reported that a logistic regression model considering age, BMD and spine fracture status provided as much predictive information as a model considering these factors plus the remaining WHO clinical risk factors. The current analysis assesses morphometric vertebral fracture and/or nonvertebral fragility fracture at 5 years using data from an additional 1964 CaMos subjects who have now completed 5 years of follow-up (total N=4725). Vertebral fractures were identified from lateral spine radiographs assessed using quantititative morphometry at baseline and end point. Nonvertebral fragility fractures were determined by questionnaire and confirmed using radiographs or medical records; fragility fracture was defined as occurring with minimal or no trauma. In this analysis, a model including age, BMD and spine fracture status provided a gradient of risk per s.d. (GR/s.d.) of 1.88 and captured most of the predictive information of a model including morphometric spine fracture status, BMD and all WHO clinical risk factors (GR/s.d. 1.92). For comparison, this model provided more information than a model considering BMD and the WHO clinical risk factors (GR/s.d. 1.74). These findings confirm the value of age, BMD and spine fracture status for predicting fracture risk.
[Show abstract][Hide abstract] ABSTRACT: Using prospective data from the Canadian Multicentre Osteoporosis Study (CaMos), we compared health utilities index (HUI) scores after 5 years of follow-up among participants (50 years and older) with and without incident clinical fractures. Incident fractures had a negative impact on HUI scores over time.
This study examined change in health-related quality of life (HRQL) in those with and without incident clinical fractures as measured by the HUI.
The study cohort was 4,820 women and 1,783 men (50 years and older) from the CaMos. The HUI was administered at baseline and year 5. Participants were sub-divided into incident fracture groups (hip, rib, spine, forearm, pelvis, other) and were compared with those without these fractures. The effects of both time and fracture type on HUI scores were examined in multivariable regression analyses.
Men and women with hip fractures, compared to those without, had lower HUI measures that ranged from -0.05 to -0.25. Both women and men with spine fractures had significant deficits on the pain attributes (-0.07 to -0.12). In women, self-care (-0.06), mobility and ambulation (-0.05) were also negatively impacted. Women with rib fractures had deficits similar to women with spine fractures, and these effects persisted over time. In men, rib fractures did not significantly affect HUI scores. Pelvic and forearm fractures did not substantially influence HUI scores.
The HUI was a sensitive measure of HRQL change over time. These results will inform economic analyses evaluating osteoporosis therapies.
Osteoporosis International 10/2008; 20(5):703-14. · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We examined osteoporosis diagnosis/treatment in 2,187 community dwelling men age 50+. After five years in the study, 90% of men with fragility fractures remained undiagnosed and untreated for osteoporosis. The need to treat fragility fractures is well established in guidelines, and these numbers represent an important care gap.
Whether physicians in the community are recognizing and appropriately treating osteoporosis and fragility fractures in men remains unknown. We examined the rate of diagnosis and treatment in community dwelling men participating in the Canadian Multicentre Osteoporosis Study (CaMos).
Between February 1996 and September 2002, 2,187 participants were recruited from nine sites across Canada and prospectively followed. Information on osteoporosis diagnosis, fractures, medications were collected annually by a detailed questionnaire. DXA examination of lumbar spine (L1-4) and hip were conducted at baseline and year five.
Diagnosis and treatment in men with clinical fragility fractures was low: at baseline and year five only 2.3% and 10.3% of men with a clinical fracture reported an osteoporosis diagnosis, respectively. At year five, 90% of men with a clinical fragility fracture were untreated. Hip fractures were the most commonly treated (37.5% by year five). A diagnosis of osteoporosis resulted in greater treatment: 67% of participants with diagnosed osteoporosis were treated with a bisphosphonate and 87% were taking calcium and/or vitamin D (year five).
In this population-based study, both a diagnostic and therapeutic gap existed between knowledge and practice related to fragility fractures and osteoporosis in men aged >or=50 years.
Osteoporosis International 04/2008; 19(4):581-7. · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hip fracture is associated with recurrent fractures and increased mortality. The results of our retrospective cohort study support the use of antiresorptive agents to prevent recurrent hip fractures in this population.
Hip fracture, the most serious consequence of osteoporosis, is associated with recurrent fractures and increased mortality. Antiresorptive therapy has proven efficacy in the prevention of fractures after vertebral fractures. It is unknown if it can prevent recurrent fractures after a hip fracture.
We designed a population based, retrospective cohort study, using administrative databases and identified patients hospitalized for a hip fracture between 1996 and 2002. The exposure was defined as being dispensed a prescription for an antiresorptive agent at any time following discharge. Multivariate Cox regression models were used to estimate the hazard ratio of recurrent hip fracture. Subgroup and propensity score analyses were performed.
A total of 20,644 patients were identified; 6,779 filled a prescription for antiresorptive agents. There were 992 recurrent hip fractures. Patients exposed to antiresorptives had a 26% reduction in the rate of recurrent fractures (adjusted hazard ratio 0.74; 95% CI, 0.64-0.86) compared to patients who were not. All subgroups experienced a reduction in recurrent fracture, except the very elderly. Propensity score analyses were consistent with the main analysis.
Antiresorptive therapy reduces the risk of recurrent hip fractures in elderly patients. These results provide evidence that this therapy should be considered for secondary prevention of hip fractures.
Osteoporosis International 01/2008; 18(12):1625-32. · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The use of cyclooxygenase-2 (COX-2) inhibitors has been demonstrated to not only impair load-induced bone formation but also prevent menopause-associated bone loss. We hypothesized that COX-2 inhibitor use would be associated with increased bone mineral density (BMD) in postmenopausal women not using estrogen therapy and, conversely, with decreased BMD in men.
The Canadian Multicentre Osteoporosis Study is a longitudinal, randomly selected, population-based community cohort. We present data from men (n=2,004) and postmenopausal women age 65 and older (n=2,776) who underwent a BMD measurement and structured interview in the 5th year of the study. The outcome measure was percent difference in BMD (g/cm(2)).
Daily COX-2 inhibitor use was reported by 394 subjects. In men, daily use of COX-2 inhibitors was associated with a lower BMD at all hip sites, with a percent difference of -3.1% [95% confidence interval (CI), -6.0, -0.3] between users and nonusers at total hip. In postmenopausal women not using estrogen replacement therapy, daily COX-2 inhibitor use was associated with higher BMD at most sites [percent difference at total hip: +3.0% (95% CI, 0.3, 5.8)]. These effects appeared to be dose-dependent.
COX-2 inhibitor use was associated with a lower BMD in men and, on the other hand, with a higher BMD in postmenopausal women not using estrogen replacement therapy. Men who have used COX-2 inhibitors may wish to seek BMD measurement to assess their fracture risk. However, COX-2 inhibitors may have utility in postmenopausal women if bone-selective analogs can be developed.
Osteoporosis International 02/2006; 17(9):1410-9. · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It has been suggested that bone mineral density (BMD) measurements should be made at multiple sites, and that the lowest T-score should be taken for the purpose of diagnosing osteoporosis.
The aim of this study was to examine the use of BMD measurements at the femoral neck and lumbar spine alone and in combination for fracture prediction.
We studied 19,071 individuals (68% women) from six prospective population-based cohorts in whom BMD was measured at both sites and fracture outcomes documented over 73,499 patient years. BMD values were converted to Z-scores, and the gradient of risk for any osteoporotic fracture and for hip fracture was examined by using a Poisson model in each cohort and each gender separately. Results of the different studies were merged using weighted beta-coefficients.
The gradients of risk for osteoporotic fracture and for hip fracture were similar in men and women. In men and women combined, the risk of any osteoporotic fracture increased by 1.51 [95% confidence interval (CI)=1.42-1.61] per standard deviation (SD) decrease in femoral-neck BMD. For measurements made at the lumbar spine, the gradient of risk was 1.47 (95% CI=1.38-1.56). Where the minimum of the two values was used, the gradient of risk was similar (1.55; 95% CI=1.45-1.64). Higher gradients of risk were observed for hip fracture outcomes: with BMD at the femoral neck, the gradient of risk was 2.45 (95% CI=2.10-2.87), with lumbar BMD was 1.57 (95% CI=1.36-1.82), and with the minimum value of either femoral neck and lumbar spine was 2.11 (95% CI=1.81-2.45). Thus, selecting the lowest value for BMD at either the femoral neck or lumbar spine did not increase the predictive ability of BMD tests. By contrast, the sensitivity increased so that more individuals were identified but at the expense of specificity. Thus, the same effect could be achieved by using a less stringent T-score for the diagnosis of osteoporosis.
Since taking the minimum value of the two measurements does not improve predictive ability, its clinical utility for the diagnosis of osteoporosis is low.
Osteoporosis International 02/2006; 17(4):527-34. · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Low body mass index (BMI) is a well-documented risk factor for future fracture. The aim of this study was to quantify this effect and to explore the association of BMI with fracture risk in relation to age, gender and bone mineral density (BMD) from an international perspective using worldwide data. We studied individual participant data from almost 60,000 men and women from 12 prospective population-based cohorts comprising Rotterdam, EVOS/EPOS, CaMos, Rochester, Sheffield, Dubbo, EPIDOS, OFELY, Kuopio, Hiroshima, and two cohorts from Gothenburg, with a total follow-up of over 250,000 person years. The effects of BMI, BMD, age and gender on the risk of any fracture, any osteoporotic fracture, and hip fracture alone was examined using a Poisson regression model in each cohort separately. The results of the different studies were then merged. Without information on BMD, the age-adjusted risk for any type of fracture increased significantly with lower BMI. Overall, the risk ratio (RR) per unit higher BMI was 0.98 (95% confidence interval [CI], 0.97-0.99) for any fracture, 0.97 (95% CI, 0.96-0.98) for osteoporotic fracture and 0.93 (95% CI, 0.91-0.94) for hip fracture (all p <0.001). The RR per unit change in BMI was very similar in men and women ( p >0.30). After adjusting for BMD, these RR became 1 for any fracture or osteoporotic fracture and 0.98 for hip fracture (significant in women). The gradient of fracture risk without adjustment for BMD was not linearly distributed across values for BMI. Instead, the contribution to fracture risk was much more marked at low values of BMI than at values above the median. This nonlinear relation of risk with BMI was most evident for hip fracture risk. When compared with a BMI of 25 kg/m(2), a BMI of 20 kg/m(2) was associated with a nearly twofold increase in risk ratio (RR=1.95; 95% CI, 1.71-2.22) for hip fracture. In contrast, a BMI of 30 kg/m(2), when compared with a BMI of 25 kg/m(2), was associated with only a 17% reduction in hip fracture risk (RR=0.83; 95% CI, 0.69-0.99). We conclude that low BMI confers a risk of substantial importance for all fractures that is largely independent of age and sex, but dependent on BMD. The significance of BMI as a risk factor varies according to the level of BMI. Its validation on an international basis permits the use of this risk factor in case-finding strategies.
Osteoporosis International 11/2005; 16(11):1330-8. · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Osteoporosis is a common condition characterized by reduced skeletal strength and increased susceptibility to fracture. The single major risk factor for osteoporosis is low bone mineral density (BMD) and strong evidence exists that genetic factors are in part responsible for an individual's BMD. A cohort of 40 multiplex Caucasian families selected through a proband with osteoporosis was genotyped for microsatellite markers spaced at an average of 10 cM, and linkage to femoral neck (FN), lumbar spine (LS) and trochanter (TR) BMD was analyzed using univariate and bivariate variance component linkage analysis. Maximum univariate multipoint lod-scores were 2.87 on chromosome 1p36 for FN BMD, 1.89 on 6q27 for TR BMD, and 2.15 on 7p15 for LS BMD. Results of bivariate linkage analysis were highly correlated with those of the univariate analysis, although generally less significant, suggesting the possibility that some of these susceptibility loci may exert pleiotropic effects on multiple skeletal sites.
European Journal of HumanGenetics 07/2005; 13(6):781-8. · 4.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Smoking is widely considered a risk factor for future fracture. The aim of this study was to quantify this risk on an international basis and to explore the relationship of this risk with age, sex and bone mineral density (BMD). We studied 59,232 men and women (74% female) from ten prospective cohorts comprising EVOS/EPOS, DOES, CaMos, Rochester, Sheffield, Rotterdam, Kuopio, Hiroshima and two cohorts from Gothenburg. Cohorts were followed for a total of 250,000 person-years. The effect of current or past smoking, on the risk of any fracture, any osteoporotic fracture and hip fracture alone was examined using a Poisson model for each sex from each cohort. Covariates examined were age, sex and BMD. The results of the different studies were merged using the weighted beta-coefficients. Current smoking was associated with a significantly increased risk of any fracture compared to non-smokers (RR=1.25; 95% Confidence Interval (CI)=1.15-1.36). Risk ratio (RR) was adjusted marginally downward when account was taken of BMD, but it remained significantly increased (RR=1.13). For an osteoporotic fracture, the risk was marginally higher (RR=1.29; 95% CI=1.13-1.28). The highest risk was observed for hip fracture (RR=1.84; 95% CI=1.52-2.22), but this was also somewhat lower after adjustment for BMD (RR=1.60; 95% CI=1.27-2.02). Risk ratios were significantly higher in men than in women for all fractures and for osteoporotic fractures, but not for hip fracture. Low BMD accounted for only 23% of the smoking-related risk of hip fracture. Adjustment for body mass index had a small downward effect on risk for all fracture outcomes. For osteoporotic fracture, the risk ratio increased with age, but decreased with age for hip fracture. A smoking history was associated with a significantly increased risk of fracture compared with individuals with no smoking history, but the risk ratios were lower than for current smoking. We conclude that a history of smoking results in fracture risk that is substantially greater than that explained by measurement of BMD. Its validation on an international basis permits the use of this risk factor in case finding strategies.
Osteoporosis International 03/2005; 16(2):155-62. · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aims of the present study were to determine whether a parental history of any fracture or hip fracture specifically are significant risk factors for future fracture in an international setting, and to explore the effects of age, sex and bone mineral density (BMD) on this risk. We studied 34,928 men and women from seven prospectively studied cohorts followed for 134,374 person-years. The cohorts comprised the EPOS/EVOS study, CaMos, the Rotterdam Study, DOES and cohorts at Sheffield, Rochester and Gothenburg. The effect of family history of osteoporotic fracture or of hip fracture in first-degree relatives, BMD and age on all clinical fracture, osteoporotic fracture and hip fracture risk alone was examined using Poisson regression in each cohort and for each sex. The results of the different studies were merged from the weighted beta coefficients. A parental history of fracture was associated with a modest but significantly increased risk of any fracture, osteoporotic fracture and hip fracture in men and women combined. The risk ratio (RR) for any fracture was 1.17 (95% CI=1.07-1.28), for any osteoporotic fracture was 1.18 (95% CI=1.06-1.31), and for hip fracture was 1.49 (95% CI=1.17-1.89). The risk ratio was higher at younger ages but not significantly so. No significant difference in risk was seen between men and women with a parental history for any fracture (RR=1.17 and 1.17, respectively) or for an osteoporotic fracture (RR=1.17 and 1.18, respectively). For hip fracture, the risk ratios were somewhat higher, but not significantly higher, in men than in women (RR=2.02 and 1.38, respectively). A family history of hip fracture in parents was associated with a significant risk both of all osteoporotic fracture (RR 1.54; 95CI=1.25-1.88) and of hip fracture (RR=2.27; 95% CI=1.47-3.49). The risk was not significantly changed when BMD was added to the model. We conclude that a parental history of fracture (particularly a family history of hip fracture) confers an increased risk of fracture that is independent of BMD. Its identification on an international basis supports the use of this risk factor in case-finding strategies.
[Show abstract][Hide abstract] ABSTRACT: Previous fracture is a well-documented risk factor for future fracture. The aim of this study was to quantify this risk on an international basis and to explore the relationship of this risk with age, sex, and bone mineral density (BMD). We studied 15259 men and 44902 women from 11 cohorts comprising EVOS/EPOS, OFELY, CaMos, Rochester, Sheffield, Rotterdam, Kuopio, DOES, Hiroshima, and two cohorts from Gothenburg. Cohorts were followed for a total of 250000 person-years. The effect of a prior history of fracture on the risk of any fracture, any osteoporotic fracture, and hip fracture alone was examined using a Poisson model for each sex from each cohort. Covariates examined were age, sex, and BMD. The results of the different studies were merged by using the weighted beta-coefficients. A previous fracture history was associated with a significantly increased risk of any fracture compared with individuals without a prior fracture (RR = 1.86; 95% CI = 1.75-1.98). The risk ratio was similar for the outcome of osteoporotic fracture or for hip fracture. There was no significant difference in risk ratio between men and women. Risk ratio (RR) was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any fracture (8%) and for hip fracture (22%). The risk ratio was stable with age except in the case of hip fracture outcome where the risk ratio decreased significantly with age. We conclude that previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by measurement of BMD. Its validation on an international basis permits the use of this risk factor in case finding strategies.
[Show abstract][Hide abstract] ABSTRACT: In order to evaluate the utility of peripheral measurement of bone mineral density (BMD) in the diagnosis of osteoporosis, we measured BMD at the spine and femoral neck with central dual-energy X-ray absorptiometry (DXA), at phalanx with AccuDXA (Schick) as well as proximal and distal forearm with pDXA (Norland) in 835 women ranging in age from 20 to 85 yr. In receiver operating characteristic (ROC) curves, where a positive case was defined as a T-score < or = -2.5 either on spine or femoral neck, the areas under the curve were not significantly different between sites. At a T-score of -2.5 as determined by each peripheral apparatus, sensitivity and specificity were, respectively, 0.39 and 0.95 for phalanx and 0.75 and 0.85 for proximal forearm whereas they were 0.42 and 0.96 for distal forearm. Using optimal absolute BMD cutoff values improved the results. Sensitivity and specificity were, respectively, 0.79 and 0.83 for phalanx at an absolute BMD value of 0.436 and 0.84 and 0.79 for proximal forearm at a value of 0.703, whereas they were 0.90 and 0.75 for distal forearm at a value of 0.208. Combining the two forearm measurements improves the results slightly. At cutoff values of 0.641 and 0.252, respectively for proximal and distal forearms, sensitivity was 0.83 and specificity was 0.84. Therefore, a peripheral measurement of BMD together with a good clinical evaluation of the osteoporosis risk profile of the patient, can be an interesting tool for the diagnosis of osteoporosis in areas where central DXA is not available.
Journal of Clinical Densitometry 01/2004; 7(1):111-8. · 1.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Osteoporotic fractures can be a major cause of morbidity. It is important to determine the impact of fractures on health-related quality of life (HRQL). A total of 3,394 women and 1,122 men 50 years of age and older, who were recruited for the Canadian Multicentre Osteoporosis Study (CaMos), participated in this cross-sectional study. Minimal trauma fractures of the hip, pelvis, spine, lower body (included upper and lower leg, knee, ankle, and foot), upper body (included arm, elbow, sternum, shoulder, and clavicle), wrist and hand (included forearm, hand, and finger), and ribs were studied. Participants with subclinical vertebral deformities were also examined. The Health Utilities Index Mark II and III Systems were used to assess HRQL. Past osteoporotic fractures varied in prevalence from 1.2% (pelvis) to 27.8% (lower body) in women and 0.3% (pelvis) to 29.3% (wrist) in men. Multivariate linear regression analyses [parameter estimates and corresponding 95% confidence intervals (CI)] indicated that minimal trauma fractures were negatively associated with HRQL and that this relationship depends on fracture type and gender. The multi-attribute scores for the Mark II system were negatively related to hip (-0.05; 95% CI: -0.09, -0.01), lower body (-0.02; 95% CI: -0.03, -0.000), and subclinical vertebral fractures (-0.02; 95% CI: -0.03, -0.00) for women. The multi-attribute scores for the Mark III system were negatively related to hip (-0.09; 95% CI: -0.14, -0.03) and rib fractures (-0.06; 95% CI: -0.11, -0.00) for women, and rib fractures (-0.06; 95% CI: -0.12, -0.00) for men. In conclusion, this study demonstrates a negative association between osteoporotic fractures and quality of life in both women and men.
Osteoporosis International 12/2003; 14(11):895-904. · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Two candidate genes for bone mineral density (BMD), tumor necrosis factor alpha receptor 2 (TNFRSF1B) and lysyl hydroxylase (PLOD1), have been scanned for single nucleotide polymorphisms (SNPs) within their coding and promoter regions. These two genes, separated by about 200 kb, are located within the chromosomal interval 1p36.2-1p36.3 that has been linked to femoral neck BMD. In a patient population (n = 104) of European descent, there were four SNPs within TNFRSF1B and six SNPs within PLOD1 that occurred with greater than 5% frequency. There was significant linkage disequilibrium within both genes. Single marker analysis revealed significant association for one SNP located in intron 6 of PLOD1 and lumbar spine BMD (P = 0.01). Allelic haplotypes that encompassed the four SNPs in TNFRSF1B or the six SNPs in PLOD1 were assigned using a Bayesian algorithm as implemented in the program Haplotyper. Association of TNFRSF1B haplotypes with femoral neck BMD was statistically significant (P = 0.01). Similarly, PLOD1 haplotypes demonstrated a statistically significant association with spinal BMD (P = 0.04). These findings strengthen the potential importance of chromosome 1p36.2-1p36.3 in contributing to BMD variation, and are consistent with genetic variation in either PLOD1, TNFRSF1B or nearby genes playing a role in the phenotype.
Calcified Tissue International 09/2003; 73(2):140-6. · 2.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This cross-sectional cohort study of 5566 women and 2187 men 50 years of age and older in the population-based Canadian Multicentre Osteoporosis Study was conducted to determine whether reported past diseases are associated with bone mineral density or prevalent vertebral deformities. We examined 12 self-reported disease conditions including diabetes mellitus (types 1 or 2), nephrolithiasis, hypertension, heart attack, rheumatoid arthritis, thyroid disease, breast cancer, inflammatory bowel disease, neuromuscular disease, Paget's disease, and chronic obstructive pulmonary disease. Multivariate linear and logistic regression analyses were performed to determine whether there were associations among these disease conditions and bone mineral density of the lumbar spine, femoral neck, and trochanter, as well as prevalent vertebral deformities. Bone mineral density measurements were higher in women and men with type 2 diabetes compared with those without after appropriate adjustments. The differences were most notable at the lumbar spine (+0.053 g/cm2), femoral neck (+0.028 g/cm2), and trochanter (+0.025 g/cm2) in women, and at the femoral neck (+0.025 g/cm2) in men. Hypertension was also associated with higher bone mineral density measurements for both women and men. The differences were most pronounced at the lumbar spine (+0.022 g/cm2) and femoral neck (+0.007 g/cm2) in women and at the lumbar spine (+0.028 g/cm2) in men. Although results were statistically inconclusive, men reporting versus not reporting past nephrolithiasis appeared to have clinically relevant lower bone mineral density values. Bone mineral density differences were -0.022, -0.015, and -0.016 g/cm2 at the lumbar spine, femoral neck, and trochanter, respectively. Disease conditions were not strongly associated with vertebral deformities. In summary, these cross-sectional population-based data show that type 2 diabetes and hypertension are associated with higher bone mineral density in women and men, and nephrolithiasis may be associated with lower bone mineral density in men. The importance of these associations for osteoporosis case finding and management require further and prospective studies.
Journal of Bone and Mineral Research 05/2003; 18(4):784-90. · 6.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Osteoporosis is a common condition characterized by reduced skeletal strength and increased susceptibility to fracture. Eight million Americans over the age of 50 have osteoporosis of the femoral neck. The most important risk factor for osteoporosis is low bone mineral density (BMD), and several epidemiological studies have shown the importance of genetic factors in determining variability of BMD. An initial genome screen in seven large pedigrees suggested that a candidate region conferring susceptibility to low BMD of the femoral neck was located on chromosome 1p36. We have now confirmed and extended this finding by analyzing nine microsatellite markers spanning a 40 cM interval across the candidate region in an expanded sample of 42 families. Heritability of femoral neck BMD was estimated as 0.51 +/- 0.13 in these families, after accounting for the effects of age, sex, body mass index, height and weight. Variance component linkage analysis yielded a maximum multipoint LOD score of 3.53 for linkage of femoral neck BMD to a quantitative trait locus (QTL) located near marker D1S214. The associated empirical P-value by simulation analysis was equal to 0.0001. The results strongly support the hypothesis that a major QTL controlling femoral neck BMD is located on chromosome 1p36.2-p36.3, and further analysis of candidate genes in this region is warranted.
Human Molecular Genetics 11/2001; 10(21):2447-52. · 7.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Positive and negative effects on bone mineral density (BMD) have been described as a result of the premenopausal use of oral contraceptives (OCs); increased fracture rates have also been reported. This study assessed the relation between OC use and BMD in a population-based, 9-centre, national sample of women aged 25-45 years.
Premenopausal women who had been enrolled in the Canadian Multicentre Osteoporosis Study were classified as having ever been OC users (> or = 3 months) or as having never been OC users (0 to < 3 months). Data were obtained through extensive questionnaires and measuring of participants' weight, height and the BMD of lumbar vertebrae and the proximal femur.
Of the sample of 524 women, whose mean age was 36.3 (standard deviation [SD] 5.9) years, 454 had used OCs; their mean age when they started using OCs was 19.8 (SD 3.5) years and the mean duration of use was 6.8 (SD 4.8) years. Women who had ever and those who had never used OCs showed no differences in age, age at menarche, parity, current calcium intake, exercise, body mass index (BMI), education, past irregular cycles or amenorrhea. OC users reported more alcohol and cigarette use and more use of medications to create regular cycles. Mean BMD values (adjusted for age, BMI and height) were 0.02-0.04 g/cm2 (that is, 2.3%-3.7%) lower in OC users, and were significantly lower in the spine and trochanter. The BMD of the spine in OC users was 1.03 (SD 0.12) g/cm2 versus 1.07 (SD 0.12) g/cm2 (95% confidence interval [CI] of difference -0.07 to -0.001) in those who had never used OCs. BMD was neither related to the duration of OC use nor to gynecological age at first use. Current and past users had similar BMD values.
National, population-based data show lower BMD values for the trochanter and spine in premenopausal women who have used OCs compared with those who have never used OCs.
Canadian Medical Association Journal 10/2001; 165(8):1023-9. · 6.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Health-related quality of life (HRQL) was examined in relation to prevalent fractures in 4816 community-dwelling Canadian men and women 50 years and older participating in the Canadian Multicentre Osteoporosis Study (CaMos). Fractures were of three categories: clinically recognized main fractures, subclinical vertebral fractures and fractures at other sites. Main fractures were divided and analyzed at the hip, spine, wrist/forearm, pelvis and rib sites. Baseline assessments of anthropometric data, medical history, therapeutic drug use, spinal radiographs and prevalent fractures were obtained from all participants. The SF-36 instrument was used as a tool to measure HRQL. A total of 652 (13.5%) main fractures were reported. Results indicated that hip, spine, wrist/forearm, pelvis and rib fractures had occurred in 78 (1.6%), 40 (0.8%), 390 (8.1%), 19 (0.4%) and 125 (2.6%) individuals, respectively (subjects may have had more than one main fracture). Subjects who had experienced a main prevalent fracture had lower HRQL scores compared with non-fractured participants. The largest differences were observed in the physical functioning (-4.0; 95% confidence intervals (CI): -6.0, -2.0) and role-physical functioning domains (-5.8; 95% CI: -9.5, -2.2). In women, the physical functioning domain was most influenced by hip (-14.9%; 95% CI: -20.9, -9.0) and pelvis (-18.1; 95% CI: -27.6, -8.6) fractures. In men, the role-physical domain was most affected by hip fractures (-35.7; 95% CI: -60.4, -11.1). Subjects who experienced subclinical vertebral fractures had lower HRQL scores than those without prevalent fractures. In conclusion, HRQL was lower in the physical functioning domain in women and the role-physical domain in men who sustained main fractures at the hip. Subclinical vertebral fractures exerted a moderate effect on HRQL.
Osteoporosis International 02/2001; 12(11):903-8. · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Following a 52-wk randomized controlled trial of intermittent cyclic etidronate therapy in patients using corticosteroids, we performed a 52-wk open-label trial of calcium alone in 114 corticosteroid-treated patients to determine whether the beneficial effect of etidronate is maintained after the drug is discontinued. All patients were given 500 mg/d of elemental calcium. Sixty-one and 53 patients made up the former placebo and etidronate groups, respectively. A total of 89 (98%) of patients in the former placebo and etidronate groups remained on corticosteroids throughout the second year. The mean (SE) percentage change in bone mineral density of the lumbar spine, femoral neck, and trochanter were compared between groups. The difference between groups in mean percentage change from baseline (wk 0, initiation of etidronate or placebo therapy) in the bone density of the lumbar spine, femoral neck, and trochanter, following 104 wk, was 3.8 (0.9), 3.0 (1.1), and 4.3 (1.1), respectively (p < 0.05, all sites), in favor of the former etidronate group. While not significant, the former placebo group demonstrated a slightly larger rate of decline in bone density over the second year than the former etidronate group at all three sites. Following the discontinuation of etidronate therapy, there was no accelerated bone loss and there was evidence of a residual protective effect in both the lumbar spine and femoral neck for up to 1 yr posttreatment.
Journal of Clinical Densitometry 02/2001; 4(4):363-71. · 1.71 Impact Factor