Reproductive Hormones and Longitudinal Change in Bone Mineral Density and Incident Fracture Risk in Older Men: The Concord Health and Aging in Men Project

The objectives of this study were to examine relationships between baseline levels of reproductive hormones in older men and (1) change in bone mineral density (BMD) over 5 years and (2) incident fractures over an average of 6 years' follow‐up. A total of 1705 men aged 70 years and older from the Concord Health and Ageing in Men Project (CHAMP) study were assessed at baseline (2005–2007), 2 years follow‐up (2007–2009), and 5 years follow‐up (2010–2013). At baseline, testosterone (T), dihydrotestosterone (DHT), estradiol (E2), and estrone (E1) were measured by liquid chromatography–tandem mass spectrometry (LC‐MS/MS), and sex hormone–binding globulin (SHBG), luteinizing hormone (LH), and follicle‐stimulating hormone (FSH) by immunoassay. Hip BMD was measured by dual X‐ray absorptiometry (DXA) at all three time‐points. Fracture data were collected at 4‐monthly phone calls and verified radiographically. Statistical modeling was by general estimating equations and Cox model regression. Univariate analyses revealed inverse associations for serum SHBG, FSH, and LH and positive association for E1 but not DHT or E2 with BMD loss at the hip across the three time points. Serum levels of SHBG (β = –0.071), FSH (β = –0.085), LH (β = –0.070), and E1 (β = 0.107) remained significantly associated with BMD loss in multivariate‐adjusted models; however, we were unable to identify any thresholds for accelerated BMD loss according to reproductive steroids. Incident fractures (all, n = 171; hip, n = 44; and nonvertebral, n = 139) were all significantly associated with serum SHBG, FSH, and LH levels in univariate models but none remained significantly associated in multivariate‐adjusted model. Serum T, DHT, E2, and E1 levels were not associated with incident fractures in univariate or multivariate‐adjusted analyses. In older men, lower serum SHBG, FSH, and LH and higher E1 levels protected against loss of BMD without increasing fracture rate. This means these reproductive variables may be considered as novel biomarkers of bone health during male aging. © 2015 American Society for Bone and Mineral Research.     

Higher-Impact Physical Activity Is Associated With Maintenance of Bone Mineral Density But Not Reduced Incident Falls or Fractures in Older Men: The Concord Health and Aging in Men Project

High-impact physical activities with bone strains of high magnitude and frequency may benefit bone health. This study aimed to investigate the longitudinal associations between changes in loading intensities and application rates, estimated from self-reported physical activity, with bone mineral density (BMD) changes over 5 years and also with incident falls over 2 years and long-term incident fractures in community-dwelling older men. A total of 1599 men (mean age 76.8 ± 5.4 years) from the Concord Health and Aging in Men Project (CHAMP) were assessed at baseline (2005–2007) and at 2- and 5-year follow-up. At each time point, hip and lumbar spine BMD were measured by dual-energy X-ray absorptiometry, and physical activity energy expenditure over the past week was self-reported via the Physical Activity Scale for the Elderly (PASE) questionnaire. Sum effective load ratings (ELRs) and peak force were estimated from the PASE questionnaire, reflecting the total and highest loading intensity and application rate of physical activities, respectively. Participants were contacted every 4 months over 2 years to self-report falls and over 6.0 ± 2.2 years for fractures. Hip fractures were ascertained by data linkage for 8.9 ± 3.6 years. Compared with sum ELR and PASE scores, peak force demonstrated the greatest standardized effect size for BMD maintenance at the spine (β = 9.77 mg/cm²), total hip (β = 14.14 mg/cm²), and femoral neck (β = 13.72 mg/cm²) after adjustment for covariates, including PASE components (all p < .01). Only PASE scores were significantly associated with reduced falls risk (standardized incident rate ratio = 0.90, 95% confidence interval 0.81–1.00, p = .04). All physical activity measures were significantly associated with reduced incident fractures in univariate analyses, but none remained significant after multivariable adjustments. Older men who engaged in physical activity of high and rapid impact maintained higher BMD, while higher energy expenditure was associated with reduced falls risk. Coupling traditional physical activity data with bone loading estimates may improve understanding of the relationships between physical activity and bone health. © 2020 American Society for Bone and Mineral Research (ASBMR).     

Factors Associated With Kyphosis and Kyphosis Progression in Older Men: The MrOS Study

Hyperkyphosis (HK), or increased anterior curvature of the thoracic spine, is common in older persons. Although it is thought that vertebral fractures are the major cause of HK, only about a third of those with the worst degrees of kyphosis have underlying vertebral fractures. In older men, HK is associated with increased risk of poor physical function, injurious falls, and earlier mortality, but its causes are not well understood. We studied 1092 men from the Osteoporotic Fractures in Men (MrOS) Study aged 64 to 92 years (mean age 72.8 years) who had repeated standardized radiographic measures of Cobb angle of kyphosis to identify risk factors for HK (defined as ≥50 degrees) and kyphosis progression over an interval of 4.7 years. Specifically, we examined the associations with age, body mass index (BMI), weight, weight loss, health behaviors, family history of HK, muscle strength, degenerative disc disease (DDD), bone mineral density (BMD), prevalent thoracic vertebral fractures, and incident thoracic vertebral fractures (longitudinal analyses only). Men had an average baseline kyphosis of 38.9 (standard deviation [SD] 11.4) degrees. Fifteen percent had HK (n = 161) with a mean Cobb angle of 56.7 (SD = 6.0) degrees; these men were older (p < 0.01), had lower BMI (p < 0.01), lower BMD (p < 0.01), were more likely to have family history of HK (p = 0.01), and prevalent thoracic vertebral fracture (p < 0.01) compared with the men without HK. During follow-up, men experienced an average of 1.4 degrees of kyphosis progression with DDD (p = 0.04) and lower hip BMD (p < 0.01) being identified as statistically significant and incident vertebral fractures (p = 0.05) nearly significant factors associated with worse progression. These results suggest that in older men, HK results from not only low BMD and vertebral fractures but that DDD also may play a significant role in kyphosis progression. © 2020 American Society for Bone and Mineral Research (ASBMR).     

Sarcopenic Obesity and Its Temporal Associations With Changes in Bone Mineral Density,Incident Falls,and Fractures in Older Men: The Concord Health and Ageing in Men Project

Body composition and muscle function have important implications for falls and fractures in older adults. We aimed to investigate longitudinal associations between sarcopenic obesity and its components with bone mineral density (BMD) and incident falls and fractures in Australian community‐dwelling older men. A total of 1486 men aged ≥70 years from the Concord Health and Ageing in Men Project (CHAMP) study were assessed at baseline (2005–2007), 2‐year follow‐up (2007–2009; n = 1238), and 5‐year follow‐up (2010–2013; n = 861). At all three time points, measurements included appendicular lean mass (ALM), body fat percentage and total hip BMD, hand‐grip strength, and gait speed. Participants were contacted every 4 months for 6.1 ± 2.1 years to ascertain incident falls and fractures, the latter being confirmed by radiographic reports. Sarcopenic obesity was defined using sarcopenia algorithms of the European Working Group on Sarcopenia (EWGSOP) and the Foundation for the National Institutes of Health (FNIH) and total body fat ≥30% of total mass. Sarcopenic obese men did not have significantly different total hip BMD over 5 years compared with non‐sarcopenic non‐obese men (p > 0.05). EWGSOP‐defined sarcopenic obesity at baseline was associated with significantly higher 2‐year fall rates (incidence rate ratio [IRR] 1.66; 95% confidence interval [CI] 1.16–2.37), as were non‐sarcopenic obesity (1.30; 1.04–1.62) and sarcopenic non‐obesity (1.58; 1.14–2.17), compared with non‐sarcopenic non‐obese. No association with falls was found for sarcopenic obesity using the FNIH definition (1.01; 0.63–1.60), but after multivariable adjustment, the FNIH‐defined non‐sarcopenic obese group had a reduced hazard for any 6‐year fracture compared with sarcopenic obese men (hazard ratio 0.44; 95% CI 0.23–0.86). In older men, EWGSOP‐defined sarcopenic obesity is associated with increased fall rates over 2 years, and FNIH‐defined sarcopenic obese men have increased fracture risk over 6 years compared with non‐sarcopenic obese men. © 2016 American Society for Bone and Mineral Research.     

Later Age at Onset of Independent Walking Is Associated With Lower Bone Strength at Fracture‐Prone Sites in Older Men

Later age at onset of independent walking is associated with lower leg bone strength in childhood and adolescence. However, it is unknown whether these associations persist into older age or whether they are evident at axial (central) or upper limb sites. Therefore, we examined walking age obtained at age 2 years and bone outcomes obtained by dual‐energy X‐ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) scans at ages 60 to 64 years in a nationally representative cohort study of British people, the MRC National Survey of Health and Development. It was hypothesized that later walking age would be associated with lower bone strength at all sites. Later independent walking age was associated with lower height‐adjusted hip (standardized regression coefficients with 95% confidence interval [CI] –0.179 [–0.251 to –0.107]), spine (–0.157 [–0.232 to –0.082]), and distal radius (–0.159 [–0.245 to –0.073]) bone mineral content (BMC, indicating bone compressive strength) in men (all p < 0.001). Adjustment for covariates partially attenuated these associations, primarily because of lower lean mass and adolescent sporting ability in later walkers. These associations were also evident for a number of hip geometric parameters (including cross‐sectional moment of inertia [CSMI], indicating bone bending/torsional strength) assessed by hip structural analysis (HSA) from DXA scans. Similar height‐adjusted associations were also observed in women for several hip, spine, and upper limb outcomes, although adjustment for fat or lean mass led to complete attenuation for most outcomes, with the exception of femoral shaft CSMI and spine bone area (BA). In conclusion, later independent walking age appears to have a lifelong association with bone strength across multiple skeletal sites in men. These effects may result from direct effects of early life loading on bone growth and mediation by adult body composition. Results suggest that late walking age may represent a novel risk factor for subsequent low bone strength. Existing interventions effective in hastening walking age may have positive effects on bone across life. © 2017 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.     

Vertebral Size,Bone Density,and Strength in Men and Women Matched for Age and Areal Spine BMD

To explore the possible mechanisms underlying sex‐specific differences in skeletal fragility that may be obscured by two‐dimensional areal bone mineral density (aBMD) measures, we compared quantitative computed tomography (QCT)‐based vertebral bone measures among pairs of men and women from the Framingham Heart Study Multidetector Computed Tomography Study who were matched for age and spine aBMD. Measurements included vertebral body cross‐sectional area (CSA, cm²), trabecular volumetric BMD (Tb.vBMD, g/cm³), integral volumetric BMD (Int.vBMD, g/cm³), estimated vertebral compressive loading and strength (Newtons) at L₃, the factor‐of‐risk (load‐to‐strength ratio), and vertebral fracture prevalence. We identified 981 male‐female pairs (1:1 matching) matched on age (± 1 year) and QCT‐derived aBMD of L₃ (± 1%), with an average age of 51 years (range 34 to 81 years). Matched for aBMD and age, men had 20% larger vertebral CSA, lower Int.vBMD (–8%) and Tb.vBMD (–9%), 10% greater vertebral compressive strength, 24% greater vertebral compressive loading, and 12% greater factor‐of‐risk than women (p < 0.0001 for all), as well as higher prevalence of vertebral fracture. After adjusting for height and weight, the differences in CSA and volumetric bone mineral density (vBMD) between men and women were attenuated but remained significant, whereas compressive strength was no longer different. In conclusion, vertebral size, morphology, and density differ significantly between men and women matched for age and spine aBMD, suggesting that men and women attain the same aBMD by different mechanisms. These results provide novel information regarding sex‐specific differences in mechanisms that underlie vertebral fragility. © 2014 American Society for Bone and Mineral Research.     

Associations of FGF23 With Change in Bone Mineral Density and Fracture Risk in Older Individuals

Elevated levels of the phosphate‐regulating hormone fibroblast growth factor 23 (FGF23) have been linked to greater risk of fractures in some studies, especially among individuals with chronic kidney disease (CKD). We evaluated FGF23 as a risk factor for bone loss and fractures in the Health, Aging, and Body Composition (Health ABC) study, which is a prospective biracial cohort of well‐functioning adults aged 70 to 79 years recruited at two clinical centers in the United States. The sample for the bone mineral density (BMD) analyses consisted of 2234 participants who had at least two serial total hip areal BMD measures. The fracture analyses included 2786 participants, 567 of whom sustained a fracture during a median follow up of 4.95 years. Linear mixed‐effects models were used for longitudinal measurements of total hip areal BMD and the proportional subdistribution hazard regression model subject to competing risks of death was used for risk of fracture. The median FGF23 was 46.7 (interquartile range [IQR] 36.7 to 60.2) pg/mL. The mean annualized percent change in total hip areal BMD did not vary significantly according to FGF23 quartile in all participants (p for trend = 0.70), but the effect was modified by CKD status (adjusted p for interaction <0.001). Among participants with CKD, the unadjusted mean annualized percent change in total hip areal BMD was greater with higher levels of FGF23 (unadjusted p for trend = 0.02), but the trend was attenuated with adjustment for estimated glomerular filtration rate and parathyroid hormone (adjusted p for trend = 0.30). FGF23 was not significantly associated with fracture risk in crude (hazard ratio [HR] per doubling of FGF23, 0.97; 95% CI, 0.85 to 1.12) or adjusted models (HR per doubling of FGF23, 1.02; 95% CI, 0.86 to 1.22), and these findings were not modified by gender or CKD status. FGF23 levels are not associated with bone loss or fracture risk in older adults with low prevalence of CKD. © 2015 American Society for Bone and Mineral Research.     

Low Testosterone,but Not Estradiol,Is Associated With Incident Falls in Older Men: The International MrOS Study

Fracture risk is determined by bone strength and the risk of falls. The relationship between serum sex steroids and bone strength parameters in men is well known, whereas the predictive value of sex steroids for falls is less studied. The aim of this study was to assess the associations between serum testosterone (T) and estradiol (E2) and the likelihood of falls. Older men (aged ≥65 years) from the United States (n = 1919), Sweden (n = 2495), and Hong Kong (n = 1469) participating in the Osteoporotic Fractures in Men Study had baseline T and E2 analyzed by mass spectrometry. Bioavailable (Bio) levels were calculated using mass action equations. Incident falls were ascertained every 4 months during a mean follow‐up of 5.7 years. Associations between sex steroids and falls were estimated by generalized estimating equations. Fall rate was highest in the US and lowest in Hong Kong (US 0.50, Sweden 0.31, Hong Kong 0.12 fall reports/person/year). In the combined cohort of 5883 men, total T (odds ratio [OR] per SD increase = 0.88, 95% confidence interval [CI] 0.86–0.91) and BioT (OR = 0.86, 95% CI 0.83–0.88) were associated with incident falls in models adjusted for age and prevalent falls. These associations were only slightly attenuated after simultaneous adjustment for physical performance variables (total T: OR = 0.94, 95% CI 0.91–0.96; BioT: OR = 0.91, 95% CI 0.89–0.94). E2, BioE2, and sex hormone‐binding globulin (SHBG) were not significantly associated with falls. Analyses in the individual cohorts showed that both total T and BioT were associated with falls in MrOS US and Sweden. No association was found in MrOS Hong Kong, and this may be attributable to environmental factors rather than ethnic differences because total T and BioT predicted falls in MrOS US Asians. In conclusion, low total T and BioT levels, but not E2 or SHBG, are associated with increased falls in older men. © 2017 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.     

The Limited Clinical Utility of Testosterone,Estradiol, and Sex Hormone Binding Globulin Measurements in the Prediction of Fracture Risk and Bone Loss in Older Men

Measurement of serum testosterone (T) levels is recommended in the evaluation of osteoporosis in older men and estradiol (E2) and sex hormone binding globulin (SHBG) levels are associated with the rate of bone loss and fractures, but the clinical utility of sex steroid and SHBG measurements for the evaluation of osteoporosis in men has not been examined. To evaluate whether measurements of T, E2, and/or SHBG are useful for the prediction of fracture risk or the rate of bone loss in older men, we analyzed longitudinal data from 5487 community‐based men participating in the Osteoporotic Fractures in Men (MrOS) study in the United States, Sweden, and Hong Kong. Serum T, E2, and SHBG levels were assessed at baseline; incident fractures were self‐reported at 4‐month intervals with radiographic verification (US), or ascertained via national health records (Sweden, Hong Kong). Rate of bone loss was assessed by serial measures of hip bone mineral density (BMD). We used receiver operating characteristic (ROC) curves, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) to assess improvement in prediction. Mean age at baseline was 72 to 75 years and the prevalence of low T levels (<300 ng/dL) was 7.6% to 21.3% in the three cohorts. There were 619 incident major osteoporotic and 266 hip fractures during follow‐up of approximately 10 years. Based on ROC curves, there were no improvements in fracture risk discrimination for any biochemical measure when added to models, including the Fracture Risk Assessment Tool (FRAX) with BMD. Although minor improvements in NRI were observed for the dichotomous parameters low bioavailable E2 (BioE2) (<11.4 pg/mL) and high SHBG (>59.1 nM), neither sex steroids nor SHBG provided clinically useful improvement in fracture risk discrimination. Similarly, they did not contribute to the prediction of BMD change. In conclusion, there is limited clinical utility of serum E2, T, and SHBG measures for the evaluation of osteoporosis risk in elderly men. © 2016 American Society for Bone and Mineral Research.     

Associations of 25‐Hydroxyvitamin D and 1,25‐Dihydroxyvitamin D With Bone Mineral Density,Bone Mineral Density Change,and Incident Nonvertebral Fracture

Relationships between 1,25‐dihydroxyvitamin D (1,25(OH)₂D) and skeletal outcomes are uncertain. We examined the associations of 1,25(OH)₂D with bone mineral density (BMD), BMD change, and incident non‐vertebral fractures in a cohort of older men and compared them with those of 25‐hydroxyvitamin D (25OHD). The study population included 1000 men (aged 74.6 ± 6.2 years) in the Osteoporotic Fractures in Men (MrOS) study, of which 537 men had longitudinal dual‐energy X‐ray absorptiometry (DXA) data (4.5 years of follow‐up). A case‐cohort design and Cox proportional hazards models were used to test the association between vitamin D metabolite levels and incident nonvertebral and hip fractures. Linear regression models were used to estimate the association between vitamin D measures and baseline BMD and BMD change. Interactions between 25OHD and 1,25(OH)₂D were tested for each outcome. Over an average follow‐up of 5.1 years, 432 men experienced incident nonvertebral fractures, including 81 hip fractures. Higher 25OHD was associated with higher baseline BMD, slower BMD loss, and lower hip fracture risk. Conversely, men with higher 1,25(OH)₂D had lower baseline BMD. 1,25(OH)₂D was not associated with BMD loss or nonvertebral fracture. Compared with higher levels of calcitriol, the risk of hip fracture was higher in men with the lowest 1,25(OH)₂D levels (8.70 to 51.60 pg/mL) after adjustment for baseline hip BMD (hazard ratio [HR] = 1.99, 95% confidence interval [CI] 1.19–3.33). Adjustment of 1,25(OH)₂D data for 25OHD (and vice versa) had little effect on the associations observed but did attenuate the hip fracture association of both vitamin D metabolites. In older men, higher 1,25(OH)₂D was associated with lower baseline BMD but was not related to the rate of bone loss or nonvertebral fracture risk. However, with BMD adjustment, a protective association for hip fracture was found with higher 1,25(OH)₂D. The associations of 25OHD with skeletal outcomes were generally stronger than those for 1,25(OH)₂D. These results do not support the hypothesis that measures of 1,25(OH)₂D improve the ability to predict adverse skeletal outcomes when 25OHD measures are available. © 2015 American Society for Bone and Mineral Research.     

Bone Mineral Density and Parathyroid Hormone as Independent Risk Factors for Mortality in Community‐Dwelling Older Adults: A Population‐Based Prospective Cohort Study in Brazil. The São Paulo Ageing & Health (SPAH) Study

Previous studies have shown a relationship between osteoporosis and increased mortality risk. However, none of these studies performed a concomitant evaluation of the parathyroid hormone (PTH)‐calcium‐vitamin D axis and bone mass to accurately determine the contribution of each of these parameters to survival in older subjects. Thus, we sought to investigate the association between bone parameters and mortality in a longitudinal, prospective, population‐based cohort of 839 elderly subjects. Clinical data (including history of fractures and cardiovascular events) were assessed using a specific questionnaire. Laboratory exams, including serum 25OHD and PTH, were also performed. Bone mineral density (BMD) at the lumbar spine and hip were evaluated using DXA. All analyses were performed at baseline (2005 to 2007). Mortality was recorded during follow‐up. Multivariate Cox proportional regression was used to compute hazard ratios for all‐cause and cardiovascular mortality. Over a mean 4.06 ± 1.07 years, there were 132 (15.7%) deaths. These individuals were compared to 707 subjects who were alive at the end of the coverage period for mortality data collection. In a multivariate Cox proportional hazards model, age (HR 1.32; 95% CI, 1.13 to 1.55; p = 0.001, for each 5‐year increase), male gender (HR 1.90; 95% CI, 1.30 to 2.79; p = 0.001), recurrent falls (more than two in the previous year; HR 1.65; 95% CI, 1.06 to 2.56; p = 0.026), diabetes mellitus (HR 2.17; 95% CI, 1.46 to 3.21; p < 0.001), low physical activity score (HR 1.78; 95% CI, 1.14 to 2.79; p = 0.011), prior cardiovascular event (HR 1.76; 95% CI, 1.18 to 2.63; p = 0.006), total hip BMD (HR 1.41; 95% CI, 1.15 to 1.72; p = 0.001, per each 1 SD decrease), and intact PTH (iPTH) (HR 1.06; 95% CI, 1.04 to 1.08; p < 0.001, per each 10 pg/mL increase) were independently associated with all‐cause mortality. The subjects in the highest quartile of PTH (>49 pg/mL) were at a higher risk of cardiovascular death (HR 3.09; 95% CI, 1.36 to 6.99; p = 0.007) compared with the subjects in the lowest quartile (<26 pg/mL). Low BMD and higher PTH were significantly associated with mortality in community‐dwelling older adults. These findings support the notion that careful screening of these bone parameters might lead to better management of older patients and improve outcomes in this population. © 2016 American Society for Bone and Mineral Research.     

The Prevalence of Vertebral Fractures Is Associated With Reduced Hip Bone Density and Inferior Peripheral Appendicular Volumetric Bone Density and Structure in Older Women

Vertebral fractures (VFs) are among the most severe and prevalent osteoporotic fractures. Their association with bone microstructure have been investigated in several retrospective case‐control studies with spine radiography for diagnosis of VF. The aim of this population‐based cross‐sectional study of 1027 women aged 75 to 80 years was to investigate if prevalent VF, identified by vertebral fracture assessment (VFA) by dual‐energy X‐ray absorptiometry (DXA), was associated with appendicular volumetric bone density, structure, and bone material strength index (BMSi), independently of hip areal bone mineral density (aBMD). aBMD was measured using DXA (Discovery; Hologic); BMSi with microindentation (Osteoprobe); and bone geometry, volumetric BMD, and microstructure with high‐resolution peripheral quantitative computed tomography (HRpQCT) (XtremeCT; Scanco Medical AG). aBMD was lower (spine 3.2%, total hip [TH] 3.8%) at all sites in women with VF, but tibia BMSi did not differ significantly compared to women without VF. In multivariable adjusted logistic regression models, radius trabecular bone volume fraction and tibia cortical area (odds ratio [OR] 1.26; 95% confidence interval [CI], [1.06 to 1.49]; and OR 1.27 [95% CI, 1.08 to 1.49], respectively) were associated with VF prevalence, whereas BMSi and cortical porosity were not. The risk of having one, two, or more than two VFs was increased 1.27 (95% CI, 1.04 to 1.54), 1.83 (95% CI, 1.28 to 2.61), and 1.78 (95% CI, 1.03 to 3.09) times, respectively, for each SD decrease in TH aBMD. When including either cortical area, trabecular bone volume fraction or TBS in the model together with TH aBMD and covariates, only TH aBMD remained independently associated with presence of any VF. In conclusion, TH aBMD was consistently associated with prevalent VFA‐verified VF, whereas neither trabecular bone volume fraction, cortical area, cortical porosity, nor BMSi were independently associated with VF in older women. © 2017 American Society for Bone and Mineral Research.     

Low Vitamin D Status Is Associated With Impaired Bone Quality and Increased Risk of Fracture-Related Hospitalization in Older Australian Women

The vitamin D debate relates in part to ideal public health population levels of circulating 25-hydroxyvitamin D (25OHD) to maintain bone structure and reduce fracture. In a secondary analysis of 1348 women aged 70 to 85 years at baseline (1998) from the Perth Longitudinal Study of Aging in Women (a 5-year calcium supplementation trial followed by two 5-year extensions), we examined the dose-response relations of baseline plasma 25OHD with hip DXA BMD at year 1, lumbar spine BMD, and trabecular bone score (TBS) at year 5, and fracture-related hospitalizations over 14.5 years obtained by health record linkage. Mean baseline plasma 25OHD was 66.9 ± 28.2 nmol/L and 28.5%, 36.4%, and 35.1% of women had levels <50, 50 to 74.9, and ≥75 nmol/L, respectively. Generalized additive models showed that total hip and femoral neck BMD and TBS, but not spine BMD, were higher with increasing plasma 25OHD up to 100 nmol/L. Compared with those with 25OHD <50 nmol/L, women with 25OHD ≥75 nmol/L had significantly higher total hip and femoral neck BMD at year 1 (3.3% to 3.9%) and TBS at year 5 (2.0%), all P < 0.05. During the follow-up, 27.6% of women experienced any fracture-related hospitalization and 10.6% hip fracture-related hospitalization. Penalized spline regression models showed a decrease in risk with increased 25OHD levels up to 65 nmol/L and 75 nmol/L for hip fracture and any fracture-related hospitalization, respectively. Cox regression grouped analyses showed that compared with women with 25OHD <50 nmol/L, those with 25OHD levels 50 to 74.9 and ≥75 nmol/L had significantly lower risk for hip fracture [HR 0.60 (95% CI, 0.40 to 0.91) and 0.61 (95% CI, 0.40 to 0.92), respectively], and any fracture-related hospitalization [HR 0.77 (95% CI, 0.59 to 0.99) and 0.70 (95% CI, 0.54 to 0.91), respectively]. In older white women, 25OHD levels >50 nmol/L are a minimum public health target and 25OHD levels beyond 75 nmol/L may not have additional benefit to reduce fracture risk. © 2019 American Society for Bone and Mineral Research.     

Association of Trabecular Bone Score (TBS) With Incident Clinical and Radiographic Vertebral Fractures Adjusted for Lumbar Spine BMD in Older Men: A Prospective Cohort Study

The association of trabecular bone score (TBS) with incident clinical and radiographic vertebral fractures in older men is uncertain. TBS was estimated from baseline spine dual‐energy X‐ray absorptiometry (DXA) scans for 5831 older men (mean age 73.7 years) enrolled in the Osteoporotic Fractures in Men (MrOS) study. Cox proportional hazard models were used to determine the association of TBS (per 1 SD decrease) with incident clinical vertebral fractures. Logistic regression was used to determine the association between TBS (per 1 SD decrease) and incident radiographic vertebral fracture among the subset of 4309 men with baseline and follow‐up lateral spine radiographs (mean 4.6 years later). We also examined whether any associations varied by body mass index (BMI) category. TBS was associated with a 1.41‐fold (95% confidence interval [CI] 1.23 to 1.63) higher aged‐adjusted odds of incident radiographic fracture, and this relationship did not vary by BMI (p value = 0.22 for interaction term). This association was no longer significant with further adjustment for lumbar spine bone mineral density (BMD; odds ratio [OR] = 1.11, 95% CI 0.94 to 1.30). In contrast, the age‐adjusted association of TBS with incident clinical vertebral fracture was stronger in men with lower BMI (≤ median value of 26.8 kg/m²; hazard ratio [HR] = 2.28, 95% CI 1.82 to 2.87) than in men with higher BMI (> median; HR = 1.60, 95% CI 1.31 to 1.94; p value = 0.0002 for interaction term). With further adjustment for lumbar spine BMD, the association of TBS with incident clinical vertebral fracture was substantially attenuated in both groups (HR = 1.30 [95% CI 0.99 to 1.72] among men with lower BMI and 1.11 [95% CI 0.87 to 1.41] among men with higher BMI). In conclusion, TBS is not associated with incident clinical or radiographic vertebral fracture after consideration of age and lumbar spine BMD, with the possible exception of incident clinical vertebral fracture among men with lower BMI. © 2017 American Society for Bone and Mineral Research.     

Low‐Level Cadmium Exposure Is Associated With Decreased Bone Mineral Density and Increased Risk of Incident Fractures in Elderly Men: The MrOS Sweden Study

One risk factor for osteoporosis that has attracted increasing attention in recent years is exposure to cadmium. The aim of this study was to examine the associations between low‐level cadmium exposure, from diet and smoking, and bone mineral density (BMD) and incident fractures in elderly men. The study population consisted of 936 men from the Swedish cohort of the Osteoporotic Fractures in Men (MrOS) study, aged 70 to 81 years at inclusion (years 2002 to 2004), with reliable data on cadmium in urine (U‐Cd) analyzed using inductively coupled plasma mass spectrometry in baseline samples. The participants also answered a questionnaire on lifestyle factors and medical history. BMD was measured at baseline using dual‐energy X‐ray absorptiometry (DXA) in the total body, hip, and lumbar spine. During the follow‐up period (until 2013), all new fractures were registered by date and type. Associations between BMD and U‐Cd were assessed using multiple linear regression, and associations between incident fractures and baseline U‐Cd were analyzed using Cox regression. In both cases, a number of potential confounders and other risk factors (eg, age, smoking, body mass index [BMI], and physical activity) were included in the models. We found significant negative associations between U‐Cd and BMD, with lower BMD (4% to 8%) for all sites in the fourth quartile of U‐Cd, using the first quartile as the reference. In addition, we found positive associations between U‐Cd and incident fractures, especially nonvertebral osteoporosis fractures in the fourth quartile of U‐Cd, with hazard ratios of 1.8 to 3.3 in the various models. U‐Cd as a continuous variable was significantly associated with nonvertebral osteoporosis fractures (adjusted hazard ratio 1.3 to 1.4 per μg Cd/g creatinine), also in never‐smokers, but not with the other fracture groups (all fractures, hip fractures, vertebral fractures, and other fractures). Our results indicate that even relatively low cadmium exposure through diet and smoking increases the risk of low BMD and osteoporosis‐related fractures in elderly men. © 2015 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR).     

The Initial Slope of the Variogram,Foundation of the Trabecular Bone Score,Is Not or Is Poorly Associated With Vertebral Strength

Trabecular bone score (TBS) rests on the textural analysis of dual‐energy X‐ray absorptiometry (DXA) to reflect the decay in trabecular structure characterizing osteoporosis. Yet, its discriminative power in fracture studies remains incomprehensible because prior biomechanical tests found no correlation with vertebral strength. To verify this result possibly owing to an unrealistic setup and to cover a wide range of loading scenarios, the data from three previous biomechanical studies using different experimental settings were used. They involved the compressive failure of 62 human lumbar vertebrae loaded 1) via intervertebral discs to mimic the in vivo situation (“full vertebra”); 2) via the classical endplate embedding (“vertebral body”); or 3) via a ball joint to induce anterior wedge failure (“vertebral section”). High‐resolution peripheral quantitative computed tomography (HR‐pQCT) scans acquired from prior testing were used to simulate anterior‐posterior DXA from which areal bone mineral density (aBMD) and the initial slope of the variogram (ISV), the early definition of TBS, were evaluated. Finally, the relation of aBMD and ISV with failure load (F_exp) and apparent failure stress (σ_exp) was assessed, and their relative contribution to a multilinear model was quantified via ANOVA. We found that, unlike aBMD, ISV did not significantly correlate with F_exp and σ_exp, except for the “vertebral body” case (r² = 0.396, p = 0.028). Aside from the “vertebra section” setup where it explained only 6.4% of σ_exp (p = 0.037), it brought no significant improvement to aBMD. These results indicate that ISV, a replica of TBS, is a poor surrogate for vertebral strength no matter the testing setup, which supports the prior observations and raises a fortiori the question of the deterministic factors underlying the statistical relationship between TBS and vertebral fracture risk. © 2015 American Society for Bone and Mineral Research.     

Moderate‐to‐Vigorous Physical Activity But Not Sedentary Time Is Associated With Musculoskeletal Health Outcomes in a Cohort of Australian Middle‐Aged Women

Associations between physical activity and time spent sedentary and musculoskeletal outcomes remain unclear in middle‐aged adults. This study aimed to describe associations between objectively‐measured physical activity and sedentary time and musculoskeletal health outcomes in middle‐aged women. This cross‐sectional study from a population‐based sample of 309 women (age 36 to 57 years) examined associations of total physical activity (accelerometer counts/min of wear time), and time spent sedentary, in light physical activities and moderate‐to‐vigorous physical activities (MVPA) (by Actigraph GT1M accelerometer) with lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD) (by dual‐energy X‐ray absorptiometry), lower limb muscle strength (LMS), and functional mobility and balance tests (timed up and go test [TUG], functional reach test [FRT], lateral reach test [LRT], and step test [ST]) using linear regression. Total physical activity was beneficially associated with FN BMD (values are β; 95% CI) (0.011 g/cm²; 95% CI, 0.003 to 0.019 g/cm²), LMS (2.13 kg; 95% CI, 0.21 to 4.06 kg), and TUG (–0.080 s; 95% CI, –0.129 to –0.030 s), after adjustment for confounders. MVPA was also beneficially associated with FN BMD (0.0050 g/cm²; 95% CI, 0.0007 to 0.0094 g/cm²), LMS (1.48 kg; 95% CI, 0.45 to 2.52 kg), ST (0.12 steps; 95% CI, 0.02 to 0.23 steps), and TUG (–0.043 s; 95% CI, –0.070 to –0.016 s). Associations between MVPA and LMS, TUG and ST persisted after further adjustment for sedentary time. Only TUG was associated with sedentary time, with a detrimental effect (0.075 s; 95% CI, 0.013 to 0.137 s) and this did not persist after further adjustment for MVPA. Light physical activity was not associated with any outcome. MVPA appears more important than light physical activity or sedentary time for many musculoskeletal outcomes in middle‐aged women. This needs to be considered when developing interventions to improve habitual physical activity that aim to improve musculoskeletal health. © 2016 American Society for Bone and Mineral Research.