[Show abstract][Hide abstract]ABSTRACT: For patients undergoing routine contrast-enhanced CT examinations, an opportunity exists for concurrent osteoporosis screening without additional radiation exposure or patient time using proximal femur CT x-ray absorptiometry (CTXA). We investigated the effect of IV contrast enhancement on femoral neck CTXA T-score measurement compared with DXA. This cohort included 355 adults (277 female; mean age, 59.7 ± 13.3 years; range, 21-90 years) who underwent standard contrast-enhanced CT assessment at 120kVp over an eight-year interval, as well as DXA BMD assessment within 100 days of the CT study (mean 46 ± 30 days). Linear regression and a Bland-Altman plot were performed to compare DXA and CTXA results. CTXA diagnostic sensitivity and specificity was evaluated with DXA as the reference standard. There was good correlation between DXA and CTXA (r(2) = 0.824 for both areal BMD and T-scores) and the SD of the distribution of residuals was 0.063 g/cm(2) or 0.45 T-score units. There was no trend in differences between the two measurements and a small bias was noted with DXA T-score +0.18 units higher than CTXA. CTXA had a sensitivity for discriminating normal from low bone mineral density of 94.9% (95% CI, 90.6-97.4%). For opportunistic osteoporosis screening at routine post-contrast abdominopelvic CT scans, CTXA produces T-scores similar to DXA. Since femoral neck CTXA BMD measurement is now included in the WHO FRAX® tool, this opportunistic method could help to increase osteoporosis screening since it can be applied regardless of the clinical indication for CT scanning. This article is protected by copyright. All rights reserved.
Article · Apr 2016 · Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research
[Show abstract][Hide abstract]ABSTRACT: Dual-energy X-ray absorptiometry (DXA) is a technology that is widely used to diagnose osteoporosis, assess fracture risk, and monitor changes in bone mineral density (BMD). The clinical utility of DXA is highly dependent on the quality of the scan acquisition, analysis, and interpretation. Clinicians are best equipped to manage patients when BMD measurements are correct and interpretation follows well-established standards. Poor-quality acquisition, analysis, or interpretation of DXA data may mislead referring clinicians, resulting in unnecessary diagnostic evaluations, failure to evaluate when needed, inappropriate treatment, or failure to provide medical treatment, with potentially ineffective, harmful, or costly consequences. Misallocation of limited healthcare resources and poor treatment decisions can be minimized, and patient care optimized, through meticulous attention to DXA instrument calibration, data acquisition and analysis, interpretation, and reporting. This document from the International Society for Clinical Densitometry describes quality standards for BMD testing at DXA facilities worldwide to provide guidance for DXA supervisors, technologists, interpreters, and clinicians. High-quality DXA testing is necessary for correct diagnostic classification and optimal fracture risk assessment, and is essential for BMD monitoring.
Article · Mar 2016 · Journal of Clinical Densitometry
[Show abstract][Hide abstract]ABSTRACT: Objective:
For patients undergoing contrast-enhanced CT examinations that include the proximal femur, an opportunity exists for concurrent screening bone mineral density (BMD) measurement. We investigated the effect of IV contrast enhancement on CT-derived x-ray absorptiometry areal BMD measurement.
Materials and methods:
Our cohort included 410 adults (mean age, 65.3 ± 10.0 years; range, 49-95 years) who underwent split-bolus CT urography at 120 kVp. Areal femoral neck BMD in g/cm(2) was measured on both unenhanced and contrast-enhanced CT series with asynchronous phantom calibration. Constant offset and multiplicative factor corrections for the contrast-enhanced series were derived from the Bland-Altman plot linear regression slopes.
Mean unenhanced and contrast-enhanced areal femoral neck BMD values were 0.681 ± 0.118 and 0.713 ± 0.123 g/cm(2), respectively. The SD of the distribution of residuals for the constant offset and multiplicative model corrections were 0.0232 and 0.0231, respectively. The constant offset correction associated with contrast enhancement was 0.032 ± 0.023 g/cm(2), which corresponds to 0.29 ± 0.21 T-score units using the CT-derived x-ray absorptiometry young normal areal femoral neck BMD reference SD of 0.111 g/cm(2).
For the purposes of opportunistic osteoporosis screening, contrast-enhanced abdominopelvic CT studies are equivalent to unenhanced CT and can therefore be used for femoral neck BMD assessment. This measure could greatly enhance osteoporosis screening.
Article · Feb 2016 · American Journal of Roentgenology
[Show abstract][Hide abstract]ABSTRACT: Trabecular bone score (TBS) is a software program recently approved by the US Food and Drug Administration for post-acquisition processing of lumbar spine dual-energy X-ray absorptiometry images that allows assessment of bone texture as a surrogate for bone microarchitecture. Low TBS values are associated with increased risk of major osteoporotic fracture risk in postmenopausal women and men aged 40 years and older independent of BMD. TBS data can be used to adjust FRAX probability of fracture. As such, TBS data can be useful in osteoporosis treatment initiation decisions. Following treatment initiation, TBS increases are smaller than seen with BMD; at present, there is insufficient evidence that TBS can be used to monitor treatment. TBS may be particularly helpful in fracture risk prediction for those with diabetes mellitus or receiving glucocorticoid therapy, but additional validation of existing observations is needed. In summary, TBS should not be used alone to guide treatment initiation, but can be used with FRAX to estimate fracture probability in postmenopausal women and older men, thereby facilitating treatment initiation decisions.
Article · Feb 2016 · Clinical Reviews in Bone and Mineral Metabolism
[Show abstract][Hide abstract]ABSTRACT: Previously, we reported the effects of teriparatide (TPTD) and zoledronic acid (ZOL) on bone formation based on biochemical markers and bone histomorphometry of the cancellous envelope at month 6 in postmenopausal women with osteoporosis who participated in the 12-month primary SHOTZ study. Patients were eligible to enter a 12-month extension on their original treatment regimen: TPTD 20 µg/d (s.c. injection) or ZOL 5 mg/y (i.v. infusion). A second biopsy was performed at month 24. Here we report longitudinal changes between and within each treatment group in the cancellous, endocortical, intracortical, and periosteal bone envelopes in patients with evaluable biopsies at months 6 and 24 (paired data set: TPTD, n = 10; ZOL, n = 9). Between-group differences are also reported in the larger set of patients with evaluable biopsies at month 6 (TPTD, n = 28; ZOL, n = 30). Data from the cancellous envelope at month 6 or month 24 provided a reference to compare differences across envelopes within each treatment group. The 24-month results extend our earlier report that TPTD and ZOL possess different tissue-level mechanisms of action. Moreover, these differences persisted for at least 2 years in all 4 bone envelopes. Few longitudinal differences were observed within or across bone envelopes in ZOL-treated patients, suggesting that the low bone formation indices at month 6 persisted to month 24. Conversely, the magnitude of the effect of TPTD on bone formation varied across individual envelopes: median values for mineralizing surface (MS/BS) and bone formation rate (BFR/BS) at month 6 were approximately 3- to 5-fold higher in the endocortical and intracortical envelopes compared to the cancellous envelope. While MS/BS and BFR/BS declined in these envelopes at month 24, median values continued to exceed, or were not significantly different from, those in the cancellous envelope. This study demonstrates for the first time that bone formation indices are higher with TPTD treatment than with ZOL in all 4 bone envelopes and the difference persists for at least 2 years. Moreover, the magnitude of the effect of TPTD in cortical bone remains robust at 24 months. This article is protected by copyright. All rights reserved.
Article · Feb 2016 · Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research
[Show abstract][Hide abstract]ABSTRACT: Objectives:
Sarcopenia increases falls and fracture risk. Sarcopenia clinical trials require robust quantitative tools to evaluate muscle function; jumping mechanography (JM) is likely one such tool. However, US data comparing JM with traditional tests across the lifespan is limited. This study evaluated the effect of age and sex on JM compared with traditional function tests and lean mass.
US adults (213 women/119 men; mean age 65.4 years, range 27-96) performed functional tests including JM, Short Physical Performance Battery (SPPB) and grip strength (GS). Appendicular lean mass (ALM) was measured using DXA.
Men had higher relative jump power [mean (SD) 28.5 (10.52) vs. 21.9 (7.11) W/kg], GS [35.5 (9.84) vs. 22.7 (6.98) kg] and ALM/ht(2) [8.25 (1.35) vs. 6.99 (1.38) kg/m(2)] (all p<0.0001); no difference was observed for SPPB components. JM parameters were more strongly correlated with age than traditional tests (R(2)=0.38-0.61 vs. R(2)=0.01-0.28) and weakly with GS and chair rise time (R(2)=0.30-0.36).
JM parameters are correlated with GS and chair rise time and demonstrate stronger correlations with age. JM shows promise as a valuable tool to evaluate and monitor interventions for sarcopenia as it could potentially detect change in muscle function more precisely than existing tools.
Full-text Article · Dec 2015 · Journal of musculoskeletal & neuronal interactions
[Show abstract][Hide abstract]ABSTRACT: PURPOSE:
For patients undergoing CT colonography (CTC), the screening presents an opportunity for concurrent osteoporosis screening, without increasing radiation exposure or the time involved for the patient, using proximal femur quantitative CT-CT x-ray absorptiometry (QCT-CTXA).
This cohort included 129 women and 112 men (mean age: 60.1 ± 8.2 years; range: 50-95 years) who underwent CTC between March 2013 and September 2014. Areal bone mineral density (BMD; g/cm(2)), and resultant left femoral neck T-score, was prospectively measured on the supine CT series. QCT results were reported with the CTC. Chart review evaluated whether the patients were eligible for BMD screening according to guidelines from the US Preventive Services Task Force and the National Osteoporosis Foundation guidelines; whether they had undergone prior BMD testing; and whether QCT results changed patient management.
Overall, 68.0% (164 of 241) of patients from this cohort had not previously undergone BMD screening. According to the National Osteoporosis Foundation guidelines, 44.0% (106 of 241) of patients were eligible for screening. T-scores within the osteopenic and osteoporotic range were detected in 32.3% (78 of 241) and 5.0% (12 of 241) of patients, respectively. Of these patients with low BMD, 66.7% (60 of 90) either had not previously undergone screening or were eligible for BMD testing. Reporting of QCT-CTXA T-scores altered management in 9 patients (3.7%) who had low BMD.
Maximizing the pre-existing value from imaging studies is crucial in the current era of health care reform. We demonstrate that colorectal and osteoporosis screening can be combined at CT examination, adding clinical and likely economic value.
Article · Oct 2015 · Journal of the American College of Radiology
[Show abstract][Hide abstract]ABSTRACT: The primary aim of this study was to assess dietary vitamin D intake and compliance with a recommended vitamin D supplementation program in a collegiate athlete population. Subsequently, associations between dietary intake, compliance with supplementation, and 25-hydroxyvitamin D [25(OH)D] levels were investigated. This study retrospectively reviewed vitamin D data for 256 athletes across 13 sports at one NCAA Division I University. Independent variables were gender, skin tone, sport, season of year, dietary intake of vitamin D, and supplementation compliance. The main outcome measure was serum 25(OH)D. Low vitamin D status was defined as 25(OH)D level less than 30 ng/mL. Supplementation was recommended for athletes with low status. In fall, 35.5% of athletes had levels less than 30 ng/mL. Mean 25(OH)D level declined (P < .001) between fall (40.7 ± 7.5 ng/mL) and winter (32.5 ± 7.3 ng/mL) in non-supplemented athletes. Supplementation increased 25(OH)D levels by 8.5 ± 9.5 ng/mL (95% confidence interval: 6.6 to 10.4) in 12 weeks. On average athletes reported moderate compliance, taking approximately half of their prescribed supplements. There was a weak correlation between percent supplement compliance and 25(OH) D levels (r = 0.257, P = .011). Athletes with better vitamin D status had higher intake of milk (among freshmen only, P = .042) and yogurt (among all athletes, P = .025). Increasing dietary intake of vitamin D-rich foods and moderate to good compliance with recommended supplementation may help collegiate athletes improve or maximize their vitamin D status.
Article · Sep 2015 · Athletic Training and Sports Health Care
[Show abstract][Hide abstract]ABSTRACT: Sarcopenia is common in later life and may be associated with adverse health outcomes such as disability, falls and fracture. There is no consensus definition for its diagnosis although diagnostic algorithms have been proposed by the European Working Group for Sarcopenia in Older People (EWGSOP), the International Working Group on Sarcopenia (IWGS) and the Foundation for the National Institutes of Health Sarcopenia Project (FNIH). More recently, Binkley and colleagues devised a score-based system for the diagnosis of "dysmobility syndrome" in an attempt to combine adverse musculoskeletal phenotypes, including sarcopenia and osteoporosis, in order to identify older individuals at particular risk. We applied these criteria to participants from the Hertfordshire Cohort Study to define their prevalence in an unselected cohort of UK community-dwelling older adults and assess their relationships with previous falls and fracture. Body composition and areal bone mineral density were measured using dual-energy X-ray absorptiometry, gait speed was determined by a 3-m walk test and grip strength was assessed with a Jamar hand-held dynamometer. Researcher-administered questionnaires were completed detailing falls and fracture history. The prevalence of sarcopenia in this cohort was 3.3, 8.3 and 2.0 % using the EWGSOP, IWGS and related definition of FNIH, respectively; 24.8 % of individuals had dysmobility syndrome. Individuals with dysmobility reported significantly higher number of falls (last year and since the age of 45 years) (p < 0.01) than those without it, but no increased fracture rate was observed in this group (p = 0.96). Those with sarcopenia as defined by the IWGS reported significantly higher falls in the last year and prevalent fractures (falls in the last year: OR 2.51; CI 1.09-5.81; p = 0.03; fractures OR 2.50; CI 1.05-5.92; p = 0.04) but these significant associations were not seen when the EWGSOP definition was applied. The IWGS definition of sarcopenia appears to be an effective means of identifying individuals at risk of prevalent adverse musculoskeletal events.
Full-text Article · Jul 2015 · Calcified Tissue International
[Show abstract][Hide abstract]ABSTRACT: Osteoporosis remains under-diagnosed. Routine abdominal CT can provide opportunistic screening, but the effect of IV contrast is largely unknown. The overall performance for predicting osteoporosis was similar between enhanced and unenhanced scans. Therefore, both non-contrast and contrast-enhanced abdominal CT scans can be employed for opportunistic osteoporosis screening.
Osteoporosis is an important yet under-diagnosed public health concern. Lumbar attenuation measurement at routine abdominal CT can provide a simple opportunistic initial screen, but the effect of IV contrast has not been fully evaluated.
Mean trabecular CT attenuation values (in Hounsfield units, HU) at the L1 vertebral level were measured by oval region-of-interest (ROI) on both the unenhanced and IV-contrast-enhanced CT series in 157 adults (mean age, 62.0). All patients underwent correlative central DXA within 6 months of CT. Based on DXA BMD of the lumbar spine, femoral neck, and total proximal femur: osteoporosis, osteopenia, and normal BMD was present in 33, 77, and 47, respectively. Statistical analysis included Bland-Altman plots and receiver operating characteristic (ROC) curves.
Mean difference (±SD) in L1 trabecular attenuation between enhanced and unenhanced CT series was +11.2 HU (±19.2) (95 % CI, 8.16-14.22 HU), an 8 % difference. Intra-patient variation was substantial, but no overall trend in the HU difference was seen according to underlying BMD. ROC area under the curve (AUC) for unenhanced and enhanced CT for diagnosing osteoporosis were similar at 0.818 and 0.830, respectively (p = 0.632). Thresholds for maintaining 90 % specificity for osteoporosis were 90 HU for unenhanced and 102 HU for enhanced CT. Thresholds for maintaining 90 % sensitivity for osteoporosis were 139 HU for unenhanced and 144 HU for enhanced CT. Similar diagnostic performance was seen for diagnosing low BMD (osteoporosis or osteopenia) using higher HU cut-offs.
Contrast-enhanced CT shows an average increase of 11 HU over the unenhanced series for L1 trabecular attenuation. The overall performance for predicting osteoporosis is similar between the enhanced and unenhanced scans, thus either can be employed for initial opportunistic screening.
[Show abstract][Hide abstract]ABSTRACT: To investigate the relationship between serum 25-hydroxyvitamin D (25[OH]D) levels and nuclear cataract among participants of the Carotenoids in Age-Related Eye Disease Study (CAREDS), an ancillary study of the Women's Health Initiative (WHI) Observational Study (OS).
Nuclear cataract was assessed from slit lamp photographs (2001-2004) taken 6 years after collecting serum analyzed for 25(OH)D levels at WHI baseline (1994-1998) in 1278 CAREDS participants age 50 to 79 years. Multivariate (age, iris color, smoking, pulse pressure) odds ratios (ORs) for nuclear cataract (nuclear opacities > level 4 or cataract extraction) by quintiles of serum 25(OH)D were estimated using logistic regression.
No significant association was observed between serum 25(OH)D and nuclear cataract among women of all ages (age-adjusted OR [95% confidence interval (CI)] 0.97 [0.65-1.45]). However, there was a significant age interaction (P for interaction = 0.04). There were no significant associations in the women 70 years or older. In women younger than 70 years, we observed an inverse association between serum 25(OH)D and nuclear cataract (multivariate adjusted ORs [95% CI] 0.54 [0.29-0.99] and 0.66 [0.36-1.20] for quintiles 4 and 5 vs. 1, respectively; P = 0.03). Further adjustment for 25(OH)D determinants (body mass index, vitamin D intake, and UVB exposure) attenuated this association.
Serum 25(OH)D levels were unrelated to nuclear opacities in this study sample. However, exploratory analyses suggest a protective association in women younger than 70 years. Further investigations of the relationship between vitamin D and nuclear lens opacities are warranted.