Association between prior non-spine non-hip fractures or prevalent radiographic vertebral deformities known to be at least 10 years old and incident hip fracture.

In this large cohort of elderly women, prior non-spine non-hip fractures and radiographic vertebral deformities >10 years old were modestly associated with incident hip fracture, but the excess risks of hip fracture attributable to those prior fractures and deformities seem to wane over time. INTRODUCTION: Whereas prior clinical fractures and prevalent radiographic vertebral deformities are well-documented predictors of incident hip fracture, the excess risks of incident fractures attributable to those prior fractures and deformities may decrease over time. Current guidelines regarding the assessment of fracture risk do not consider elapsed time since prior fracture or ascertainment of radiographic vertebral deformity. MATERIALS AND METHODS: We ascertained self-reported history of prior clinical fractures and calcaneal and total hip bone BMD and performed lateral spine radiographs in a cohort of 9516 community-dwelling elderly women who had not had a prior hip fracture. We prospectively followed them to assess incident hip fracture. Prevalent radiographic vertebral deformities were identified at baseline using morphometry, and incident hip fractures were confirmed by review of radiographic reports during three follow-up periods (0-5, >5-10, and >10 years after baseline exam). RESULTS: Among women who survived for 10 or more years after the baseline exam without having had a hip fracture, a history of non-spine non-hip fracture since age 50 reported at the baseline study examination was associated with a 21% age- and calcaneal BMD-adjusted excess risk (hazard ratio [HR], 1.21; 95% CI, 1.01-1.45) for subsequent incident hip fracture. Baseline radiographic vertebral deformity was associated with a 41% age- and BMD-adjusted excess risk (HR, 1.41; 95% CI, 1.15-1.73) of hip fracture after 10 years of follow-up. In comparison, the age- and BMD-adjusted HRs of incident hip fracture during the first 5 years of follow-up associated with prior non-spine non-hip fractures reported at the baseline study exam and prevalent radiographic vertebral deformities were 1.70 (95% CI, 1.30-2.22) and 2.10 (95% CI, 1.58-2.78), respectively. CONCLUSIONS: Self-reported prior non-spine non-hip fractures and prevalent radiographic vertebral deformities known to be at least 10 years old are modestly associated with incident hip fracture. The association between these predictor fractures and subsequent hip fractures seems to wane with increased time after ascertainment of the predictor fracture. Hip fracture risk assessment strategies incorporating prior fracture history should also consider elapsed time since those prior fractures.     

Prevalent vertebral deformities predict hip fractures and new vertebral deformities but not wrist fractures. Study of Osteoporotic Fractures Research Group.

Although vertebral deformities are known to predict future vertebral deformities, little is known about their ability to predict other osteoporotic fractures. We examined the association between prevalent vertebral deformities and incident osteoporotic fractures in the Study of Osteoporotic Fractures, a prospective study of 9704 women aged 65 years and older. Prevalent vertebral deformities were determined morphometrically from spinal radiographs at baseline and incident deformities from repeat spinal radiographs after a mean of 3.7 years. Appendicular fractures were collected by postcard every 4 months for a mean of 8.3 years. During follow-up, 389 women with new vertebral deformities, 464 with hip fractures, and 574 with wrist fractures were identified. Prevalent vertebral deformities were associated with a 5-fold increased risk (relative risk 5.4, 95% confidence interval [CI] 4.4, 6.6) of sustaining a further vertebral deformity; the risk increased dramatically with both the number and severity of the prevalent deformities. Similarly, the risks of hip and any nonvertebral fractures were increased with baseline prevalent deformity, with relative risks of 2.8 (95% CI 2.3, 3.4) and 1.9 (95% CI 1.7, 2.1), respectively. Risk increased with number and severity of deformities. These associations remained significant after adjustment for age and calcaneal bone mineral density (BMD). Although there was a small increased risk of wrist fracture, this was not significant after adjusting for age and BMD. In conclusion, the presence of prevalent morphometrically defined vertebral deformities predicts future vertebral and nonvertebral fractures, including hip but not wrist fractures. Spinal radiographs identifying prevalent vertebral deformities may be a useful additional measurement to classify further a woman's risk of future fracture.     

Smoking predicts incident fractures in elderly men: Mr OS Sweden

The aim of this study was to investigate the association between smoking and bone mineral density (BMD) and radiographically verified prevalent vertebral fractures and incident fractures in elderly men. At baseline 3003 men aged 69 to 80 years of age from the Swedish Mr Os Study completed a standard questionnaire concerning smoking habits and had BMD of the hip and spine measured using dual‐energy X‐ray absorptiometry (DXA); 1412 men had an X‐ray of the thoracic‐ and lumbar spine. Radiologic registers were used to confirm reported new fractures after the baseline visit. At baseline, 8.4% were current smokers. Current smokers had a 6.2% lower BMD at the total hip and a 5.4% lower BMD at the lumbar spine (p < .001). Current smoking remained independently inversely associated with BMD at the hip and lumbar spine after adjusting for age, height, weight, calcium intake, physical activity, and centers as covariates. Prevalent vertebral fractures among current smokers were increased in unadjusted analyses [odds ratio (OR) = 1.90, 95% confidence interval (CI) 1.26–2.87] and after adjustment for lumbar BMD (OR = 1.67, 95% CI 1.09–2.55). Smokers had a high risk for two or more prevalent vertebral fractures (OR = 3.18, 95% CI 1.88–5.36). During the average follow‐up of 3.3 years, 209 men sustained an X‐ray‐verified fracture. Incident fracture risk among smokers was calculated with Cox proportional hazard models. Current smokers had an increased risk of all new fractures [hazard ratio (HR) = 1.76, 95% CI 1.19–2.61]; nonvertebral osteoporotic fractures, defined as humerus, radius, pelvis, and hip fractures (HR = 2.14, 95% CI 1.18–3.88); clinical and X‐ray‐verified vertebral fractures (HR = 2.53, 95% CI 1.37–4.65); and hip fractures (HR = 3.16, 95% CI 1.44–6.95). After adjustment for BMD, including other covariates, no significant association between smoking and incident fractures was found. Current tobacco smoking in elderly men is associated with low BMD, prevalent vertebral fractures, and incident fractures, especially vertebral and hip fractures. © 2010 American Society for Bone and Mineral Research     

Prediction of Incident Major Osteoporotic and Hip Fractures by Trabecular Bone Score (TBS) and Prevalent Radiographic Vertebral Fracture in Older Men

Trabecular bone score (TBS) has been shown to predict major osteoporotic (clinical vertebral, hip, humerus, and wrist) and hip fractures in postmenopausal women and older men, but the association of TBS with these incident fractures in men independent of prevalent radiographic vertebral fracture is unknown. TBS was estimated on anteroposterior (AP) spine dual‐energy X‐ray absorptiometry (DXA) scans obtained at the baseline visit for 5979 men aged ≥65 years enrolled in the Osteoporotic Fractures in Men (MrOS) Study and its association with incident major osteoporotic and hip fractures estimated with proportional hazards models. Model discrimination was tested with Harrell's C‐statistic and with a categorical net reclassification improvement index, using 10‐year risk cutpoints of 20% for major osteoporotic and 3% for hip fractures. For each standard deviation decrease in TBS, there were hazard ratios of 1.27 (95% confidence interval [CI] 1.17 to 1.39) for major osteoporotic fracture, and 1.20 (95% CI 1.05 to 1.39) for hip fracture, adjusted for FRAX with bone mineral density (BMD) 10‐year fracture risks and prevalent radiographic vertebral fracture. In the same model, those with prevalent radiographic vertebral fracture compared with those without prevalent radiographic vertebral fracture had hazard ratios of 1.92 (95% CI 1.49 to 2.48) for major osteoporotic fracture and 1.86 (95% CI 1.26 to 2.74) for hip fracture. There were improvements of 3.3%, 5.2%, and 6.2%, respectively, of classification of major osteoporotic fracture cases when TBS, prevalent radiographic vertebral fracture status, or both were added to FRAX with BMD and age, with minimal loss of correct classification of non‐cases. Neither TBS nor prevalent radiographic vertebral fracture improved discrimination of hip fracture cases or non‐cases. In conclusion, TBS and prevalent radiographic vertebral fracture are associated with incident major osteoporotic fractures in older men independent of each other and FRAX 10‐year fracture risks, and these data support their use in conjunction with FRAX for fracture risk assessment in older men. © 2015 American Society for Bone and Mineral Research.     

Vertebral Fracture Assessment (VFA) With a Densitometer Predicts Future Fractures in Elderly Women Unselected for Osteoporosis

Low radiation dose imaging of the lateral spine acquired with a bone densitometer for vertebral fracture assessment (VFA) has great potential for clinical use. We have undertaken an evaluation of VFA in a prospective population cohort of elderly women to examine the prevalence of vertebral fractures, their ability to predict incident fractures, and their use in targeting therapy. Women (n = 5157) ≥75 yr of age living in the general community in the United Kingdom underwent posteroanterior and lateral imaging of the spine (T₄–L₄) with a densitometer (Hologic QDR4500A) at entry to a randomized, double‐blind, controlled trial of 800 mg oral clodronate (Bonefos) or matching placebo daily over 3 yr. The women were identified from general practice registers and recruited by letter of invitation regardless of skeletal status. The proportion of vertebrae interpretable varied from 98.2% at T₁₂ to 57.1% at T₄, with >92% interpretable at levels between T₈ and L₃. As judged by BMD at the total hip, 19.6% of the women had osteoporosis, and the prevalence of vertebral fracture was 14.5%. Women with one or more vertebral fractures had a relative risk (RR) for incident osteoporotic fractures of 2.01 (95% CI, 1.64–2.47). The RR for hip fractures was 2.29 (95% CI, 1.63–3.21). After adjustment for age, femoral neck BMD, weight, and treatment, the RR was 1.50 (95% CI, 1.21–1.86) for osteoporotic fractures, with similar results for hip fractures (RR, 1.41; 95% CI, 0.99–2.02). For women with two or more vertebral fractures, the adjusted RRs were 1.97 (95% CI, 1.24–2.72) and 1.86 (95% CI, 1.14–3.03) for osteoporotic and hip fractures, respectively. We conclude that VFA can frequently detect vertebral fractures in a population cohort of elderly women. These fractures, like radiographic fractures, predict future clinical fractures independent of age, weight, and BMD. Having multiple vertebral fractures was associated with greater risk of incident osteoporotic fractures and hip fractures.     

Fractal analysis of radiographic trabecular bone texture and bone mineral density: two complementary parameters related to osteoporotic fractures.

Trabecular bone microarchitecture and bone mineral density (BMD) are two main factors related to osteoporotic fractures. Currently, however, microarchitecture is not evaluated. We have developed and validated a trabecular bone texture analysis from radiographic images. The objective was to determine if the fractal analysis of texture was able to distinguish osteoporotic fracture groups from control groups, either in vertebrae, hip, or wrist fractures, and to determine if this indicator and BMD were independent and complementary. In this cross-sectional unicenter case-control population study in postmenopausal women, 107 fracture cases were enrolled and age-matched with 197 control cases. This population comprised 40 vertebral fractures (with 70 controls), 30 hip fractures (55 controls), and 37 wrist fractures (62 controls). Hip and lumbar spine BMD were measured by double-energy X-ray absorptiometry. Fractal analysis of texture was performed on calcaneus radiographs and the result was expressed as the H parameter (H = 2-fractal dimension). The H parameter showed a lower value (0.679 +/- 0.053 SD) in fracture cases versus control cases (0.696 +/- 0.030; p = 0.007), the statistical significance persisting after adjustment for age and for lumbar spine (LS) or hip BMD. This result was confirmed in vertebral fractures (p = 0.0001) and hip fractures (p = 0.003) but not wrist fractures (p = 0.07). We determined the threshold between high and low H values and then the odds ratios (OR) of fracture for low H for BMD < or = -2.5 SD in T score and for the combinations of both parameters. The OR of fracture for low H was 1.6 (95% CI, 1.1-2.6). For LS BMD < or = -2.5 SD the OR of 6.1 (3.4-10.8) shifted to 9.0 (4.0-20.4) when we added low H and for hip BMD it shifted from 5.6 (3.3-9.4) to 8.1 (4.0-16.8). In vertebral, hip, and wrist fracture cases the results were also significant. These data have shown that the fractal analysis of texture on calcaneus radiographs can distinguish osteoporotic fracture groups from control groups. This analysis and BMD provide independent and complementary information. These data suggest that we can improve the fracture risk evaluation by adding information related to microarchitecture, derived from analysis of conventional radiographic images.     

Time since prior fracture is a risk modifier for 10‐year osteoporotic fractures

The objective of this study was to assess the importance of time since prior fracture as a risk factor for future osteoporotic fractures and how it affects 10‐year fracture rates. We identified 39,991 women 45 years of age or older undergoing baseline bone mineral density (BMD) testing (1990–2007) from a regional database that contains dual‐energy X‐ray absorptiometry (DXA) results for Manitoba, Canada. Health service records were used to identify nontrauma ICD‐9‐CM fracture codes preceding DXA, grouped as “major” fractures (n = 5178; hip, spine, forearm, and humerus) or “minor” fractures (n = 3479; ribs, sternum, pelvis, trunk, clavicle, scapula, patella, tibia/fibula, and ankle). Time since prior fracture was coded in years as less than 1, 1 to 5, 5 to 10, and more than 10. Incident fractures (ie, hip, spine, forearm, and humerus) after BMD testing were identified (mean follow‐up 4.2 years, maximum 10 years) and studied in Cox proportional‐hazards models adjusted for age, BMD T‐score, and other covariates. After BMD testing, n = 1749 (4.4%) women experienced an incident fracture. Prior major fracture was a strong risk factor for incident fracture, greatest risk in the first year [hazard ratio (HR) 1.90, 95% confidence interval (CI) 1.60–2.25], declining by more than 10 years (HR 1.62, 95% CI 1.25–2.10). Prior minor fracture was a weaker risk factor, greatest in the first year (HR 1.45, 95% CI 1.13–1.87) and no longer significant by 1 to 5 years. Major and minor fractures both showed a time‐dependent decline in importance as risk factors. In conclusion, time since prior fracture modifies future fracture risk, but prior fractures of the hip, spine, forearm, and humerus remain strong risk factors even 10 years later. Fracture risk assessment should emphasize the importance of prior fractures at these sites.     

Association of endothelial nitric oxide synthase genotypes with bone mineral density, bone loss, hip structure, and risk of fracture in older women: the SOF study

Nitric oxide (NO) is an important bone-signaling molecule. We examined the associations between the Glu298Asp polymorphism of NOS3, indices of bone strength, and the incidence of fracture among 6691 women aged 65 years and older enrolled in the Study of Osteoporotic Fractures. Calcaneal BMD was measured at an initial exam and after an average of 5.9 years of follow-up. Hip BMD was measured at an initial exam and after 3.7 years of follow-up. Baseline spine BMD and hip structural parameters were measured. Incident hip fractures were confirmed by review of radiographic reports; follow-up was greater than 98% complete. Incident vertebral fractures were defined by morphometry using lateral spine radiography at baseline and an average of 3.7 years later. The frequencies of the NOS3 Glu298Asp genotypes were Glu/Glu=46.2%, Glu/Asp=42.7%, and Asp/Asp=11.1%. There were no significant associations between NOS3 genotypes and initial calcaneal BMD, hip BMD, or rate of change in hip or calcaneal BMD. None of the hip structural parameters differed substantially by genotype. NOS3 genotype was not significantly associated with either incident or prevalent radiographic vertebral fractures. Women with the heterozygous Glu/Asp genotype had a borderline statistically significantly lower rate of hip fracture than either the Glu/Glu genotype (HR=0.87, 95% CI: 0.74, 1.01) or the Asp/Asp genotype (HR=0.78, 95% CI: 0.62, 0.98). In conclusion, the Glu298Asp polymorphism does not contribute substantially or consistently to indices of bone strength in this sample of older white women, although our findings suggest allelic variation at the NOS3 locus maybe associated with hip fracture risk. Confirmation of these findings is needed in other populations and with additional markers within and flanking the NOS3 gene region.     

Differences in Site-Specific Fracture Risk Among Older Women with Discordant Results for Osteoporosis at Hip and Spine: Study of Osteoporotic Fractures

To examine the fracture pattern in older women whose bone mineral density (BMD) T-score criteria for osteoporosis at hip and spine disagree, hip and spine BMD were measured in Study of Osteoporotic Fractures participants using dual energy X-ray absorptiometry (DXA). Hip osteoporosis was defined as T-score ≤−2.5 at femoral neck or total hip, and spine osteoporosis as T-score ≤−2.5 at lumbar spine. Incident clinical fractures were self-reported and centrally adjudicated. Incident radiographic spine fractures were defined morphometrically. Compared to women with osteoporosis at neither hip nor spine, those osteoporotic only at hip had a 3.0-fold age- and weight-adjusted increased risk for hip fracture (95% confidence interval [CI]: 2.4–3.6), and smaller increases in risk of nonhip nonspine (hazard ratios [HR] = 1.6), clinical spine (odds ratio [OR] = 2.2), and radiographic spine fractures (OR = 1.5). Women osteoporotic only at spine had a 2.8-fold increased odds of radiographic spine fracture (95% CI: 2.1–3.8), and smaller increases in risk of clinical spine (OR = 1.4), nonhip nonspine (HR = 1.6), and hip fractures (HR = 1.2). Discordant BMD results predict different fracture patterns. DXA fracture risk estimation in these patients should be site specific. Women osteoporotic only at spine would not have been identified from hip BMD measurement alone, and may have a sufficiently high fracture risk to warrant preventive treatment.     

Effect of Total Hip Bone Area on Osteoporosis Diagnosis and Fractures

DXA is affected by skeletal size, with smaller bones giving lower areal BMD despite equal material density. Whether this size effect confounds the use of BMD as a diagnostic and fracture risk assessment tool is unclear. We identified 16,205 women of white ethnicity ≥50 yr of age undergoing baseline hip assessment with DXA (1998–2002) from a population‐based database that contains all clinical DXA test results for the Province of Manitoba, Canada. Total hip measurements were categorized according to quartile in total hip bone area (Q1 = smallest, Q4 = largest). Longitudinal health service records were assessed for the presence of nontraumatic osteoporotic fracture codes during a mean of 3.2 yr of follow‐up after BMD testing (757 osteoporotic fractures, 186 hip fractures). Total hip bone area strongly affected osteoporosis diagnosis with much higher rates in Q1 (14.4%) than Q4 (8.9%). However, incident fracture rates were constant across all area quartiles, and prevalent fractures were paradoxically fewer in smaller area quartiles (p < 0.001 for trend). Age was a potential confounder that correlated positively with area (r = 0.12, p < 0.0001). When age was not included in a Cox regression model, Q1 seemed to have a lower rate of incident osteoporotic fractures (HR = 0.80, 95% CI = 0.66–0.98, reference Q4) and hip fractures (HR = 0.63, 95% CI = 0.43–0.94) for a given level of BMD. In age‐adjusted regression models, total hip BMD was strongly predictive of incident osteoporotic fractures (HR per SD = 1.83, 95% CI = 1.68–1.99) and hip fractures (HR per SD = 2.80, 95% CI = 2.33–3.35), but there was no independent effect of bone area (categorical or continuous). Nested matched subgroup analysis and ROC analysis confirmed that bone area had no appreciable effect on incident fractures. We conclude that total hip areal BMD categorizes a substantially higher fraction of women with smaller bone area as being osteoporotic despite younger age. Incident fracture rates correlate equally well with BMD across all bone area quartiles when adjusted for age.     

High Serum SHBG Predicts Incident Vertebral Fractures in Elderly Men

Previous prospective cohort studies have shown that serum levels of sex steroids and sex hormone‐binding globulin (SHBG) associate with nonvertebral fracture risk in men. The predictive value of sex hormones and SHBG for vertebral fracture risk specifically is, however, less studied. Elderly men (aged ≥65 years) from Sweden and Hong Kong participating in the Osteoporotic Fractures in Men (MrOS) study had baseline estradiol and testosterone analyzed by gas chromatography–mass spectrometry (GC‐MS) and SHBG by immunoradiometric assay (IRMA). Incident clinical vertebral fractures (n = 242 cases) were evaluated in 4324 men during an average follow‐up of 9.1 years. In a subsample of these men (n = 2256), spine X‐rays were obtained at baseline and after an average follow‐up of 4.3 years to identify incident radiographic vertebral fractures (n = 157 cases). The likelihood of incident clinical and radiographic vertebral fractures was estimated by Cox proportional hazards models and logistic regression models, respectively. Neither serum estradiol (hazard ratio [HR] per SD increase = 0.93, 95% confidence interval [CI] 0.80–1.08) nor testosterone (1.05, 0.91–1.21) predicted incident clinical vertebral fractures in age‐adjusted models in the combined data set. High serum SHBG, however, associated with increased clinical vertebral fracture risk (1.24, 1.12–1.37). This association remained significant after further adjustment for FRAX with or without bone mineral density (BMD). SHBG also associated with increased incident radiographic vertebral fracture risk (combined data set; odds ratio [OR] per SD increase = 1.23, 95% CI 1.05–1.44). This association remained significant after adjustment for FRAX with or without BMD. In conclusion, high SHBG predicts incident clinical and radiographic vertebral fractures in elderly men and adds moderate information beyond FRAX with BMD for vertebral fracture risk prediction. © 2015 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.     

Expected lifetime numbers,risks, and burden of osteoporotic fractures for 50-year old Chinese women: a discrete event simulation incorporating FRAX

This work was undertaken to provide an estimation of expected lifetime numbers, risks, and burden of fractures for 50-year-old Chinese women. A discrete event simulation model was developed to simulate the lifetime fractures of 50-year-old Chinese women at average risk of osteoporotic fracture. Main events in the model included hip fracture, clinical vertebral fracture, wrist fracture, humerus fracture, and other fracture. Fracture risks were calculated using the FRAX^® tool. Simulations of 50-year-old Chinese women without fracture risks were also carried out as a comparison to determine the burden of fractures. A 50-year-old Chinese woman at average risk of fracture is expected to experience 0.135 (95 % CI: 0.134–0.137) hip fractures, 0.120 (95 % CI: 0.119–0.122) clinical vertebral fractures, 0.095 (95 % CI: 0.094–0.096) wrist fractures, 0.079 (95 % CI: 0.078–0.080) humerus fractures, and 0.407 (95 % CI: 0.404–0.410) other fractures over the remainder of her life. The residual lifetime risk of any fracture, hip fracture, clinical vertebral fracture, wrist fracture, humerus fracture, and other fracture for a 50-year-old Chinese woman is 37.36, 11.77, 10.47, 8.61, 7.30, and 27.80 %, respectively. The fracture-attributable excess quality-adjusted life year (QALY) loss and lifetime costs are estimated at 0.11 QALYs (95 % CI: 0.00–0.22 QALYs) and US $714.61 (95 % CI: US $709.20–720.02), totaling a net monetary benefit loss of US $1,104.43 (95 % CI: US $904.09–1,304.78). Chinese women 50 years of age are at high risk of osteoporotic fracture, and the expected economic and quality-of-life burden attributable to osteoporotic fractures among Chinese women is substantial.     

Association of the VDR translation start site polymorphism and fracture risk in older women.

We evaluated the association between the VDR translation start site polymorphism and osteoporotic phenotypes among 6698 older white women. Women with the C/C genotype had lower wrist BMD and an increased risk of wrist and all non-spine/low-trauma fractures. The high frequency of this variant confers a population attributable risk that is similar to several established risk factors for fracture. INTRODUCTION: The vitamin D receptor (VDR) is a nuclear receptor that regulates bone formation, bone resorption, and calcium homeostasis. A common C to T polymorphism in exon 2 of the VDR gene introduces a new translation start site and a protein that differs in length by three amino acids (T = 427aa, C = 424aa; rs10735810). MATERIALS AND METHODS: We conducted genetic association analyses of this polymorphism, BMD, and fracture outcomes in a prospective cohort of 6698 white American women >or=65 years of age. Incident fractures were confirmed by physician adjudication of radiology reports. There were 2532 incident nontraumatic/nonvertebral fractures during 13.6 yr of follow-up including 509 wrist and 703 hip fractures. RESULTS: Women with the C/C genotype had somewhat lower distal radius BMD compared with those with the T/T genotype (CC=0.358 g/cm(2), CT=0.361 g/cm(2), TT=0.369 g/cm(2), p=0.003). The C/C genotype was also associated with increased risk of non-spine, low traumatic fractures (HR: 1.18; 95% CI: 1.04, 1.33) and wrist fractures (HR: 1.33; 95% CI: 1.01, 1.75) compared with the T/T genotype in age-adjusted models. Further adjustments for distal radius BMD only slightly attenuated these associations. The VDR polymorphism was not associated with hip fracture. The population attributable risk (PAR) of the C/C genotype for incident fractures was 6.1%. The PAR for established risk factors for fracture were: low femoral neck BMD (PAR=16.3%), maternal history of fracture (PAR=5.1%), low body weight (PAR=5.3%), corticosteroid use (PAR=1.3%), and smoking (PAR=1.6%). Similar PAR results were observed for wrist fractures. CONCLUSIONS: The common and potentially functional VDR translation start site polymorphism confers a modestly increased relative risk of fracture among older white women. However, the high frequency of this variant confers a population attributable risk that is similar to or greater than several established risk factors for fracture.     

Prediction of incident osteoporotic fractures in elderly women using the free estradiol index

A decline in postmenopausal estrogen concentration accelerates postmenopausal bone loss. We have examined the predictive power of endogenous estrogen production, DXA hip bone density (BMD), and heel quantitative ultrasound (QUS) on incident clinical fracture in a prospective 3-year population based, randomised controlled trial of calcium supplementation. Baseline blood testing on 1499 women mean (SD) age 75 (3) years for estradiol and sex hormone binding globulin measurements and ankle QUS measurements (Lunar Achilles) was undertaken. Bone density was measured using DXA (Hologic 4500A) at 1 year. Incident clinical fractures were confirmed by X-ray. At 3 years, 10% had sustained more than one incident fracture. The fracture group had significantly lower levels of free estradiol index (FEI) (0.40±0.44 versus 0.49±0.54 pmol/nmol), hip BMD (0.776±0.129 versus 0.815±0.124 g/cm²) and measures of QUS (BUA 98±8 versus 101±8 db/Hz, SOS 1504±22 versus 1514 ±26 m/s; stiffness 67±11 versus 71±11 % mean young adult), respectively, than the non-fracture group. After adjustment for age, weight, use of topical estrogen, calcium supplementation and prevalent fracture, incident fracture was predicted by free estradiol index (HR per SD: 1.43:95%CI: 1.08–1.91, P=0.013). After adjustment for BMD, SOS or stiffness, the free estradiol index no longer predicted fracture. When examined separately, the presence of a vertebral or an appendicular fracture was associated with an 18% lower free estradiol index compared with no fracture. The risk of vertebral fracture increased with decreased free estradiol index (HR per SD reduction: 1.63:95% CI: 0.91–2.92); the risk of appendicular fracture also increased with decreased free estradiol index (HR per SD reduction: 1.45:95% CI: 1.05–2.01) after adjustment for age, weight, use of topical estrogen, calcium supplementation and prevalent fracture. After further adjustment for hip BMD or QUS measures, the effect of free estradiol index was no longer significant for vertebral or appendicular fractures. Therefore, a low free estradiol index increases the probability of having an incident fracture as a result of decreased BMD. These data confirm the importance of postmenopausal estrogen concentration in the pathogenesis of osteoporosis in elderly women.     

Prediction of clinical non-spine fractures in older black and white men and women with volumetric BMD of the spine and areal BMD of the hip: the Health, Aging, and Body Composition Study*.

In a prospective study of 1446 black and white adults 70-79 yr of age (average follow-up, 6.4 yr), vertebral TrvBMD from QCT predicted non-spine fracture in black and white women and black men, but it was not a stronger predictor than total hip aBMD from DXA. Hip aBMD predicted non-spine fracture in black men. INTRODUCTION: Areal BMD (aBMD) at multiple skeletal sites predicts clinical non-spine fractures in white and black women and white men. The predictive ability of vertebral trabecular volumetric BMD (TrvBMD) for all types of clinical non-spine fractures has never been tested or compared with hip aBMD. Also, the predictive accuracy of hip aBMD has never been tested prospectively for black men. MATERIALS AND METHODS: We measured vertebral TrvBMD with QCT and hip aBMD with DXA in 1446 elderly black and white adults (70-79 yr) in the Health, Aging, and Body Composition Study. One hundred fifty-two clinical non-spine fractures were confirmed during an average of 6.4 yr of >95% complete follow-up. We used Cox proportional hazards regression to determine the hazard ratio (HR) and 95% CIs of non-spine fracture per SD reduction in hip aBMD and vertebral TrvBMD. RESULTS: Vertebral TrvBMD and hip aBMD were both associated with risk of non-spine fracture in black and white women and black men. The age-adjusted HR of fracture per SD decrease in BMD was highest in black men (hip aBMD: HR = 2.04, 95% CI = 1.03, 4.04; vertebral TrvBMD: HR = 3.00, 95% CI = 1.29, 7.00) and lowest in white men (hip aBMD: HR = 1.23, 95% CI = 0.85, 1.78; vertebral TrvBMD: HR = 1.06, 95% CI = 0.73, 1.54). Adjusted for age, sex, and race, each SD decrease in hip aBMD was associated with a 1.67-fold (95% CI = 1.36, 2.07) greater risk of fracture, and each SD decrease in vertebral TrvBMD was associated with a 1.47-fold (95% CI = 1.18, 1.82) greater risk. Combining measurements of hip aBMD and vertebral TrvBMD did not improve fracture prediction. CONCLUSIONS: Low BMD measured by either spine QCT or hip DXA predicts non-spine fracture in older black and white women and black men. Vertebral TrvBMD is not a stronger predictor than hip aBMD of non-spine fracture.     

The Importance of Previous Fracture Site on Osteoporosis Diagnosis and Incident Fractures in Women

Previous fracture increases the risk of subsequent fractures regardless of the site of the initial fracture. Fracture risk assessment tools have been developed to guide clinical management; however, no discrimination is made as to the site of the prior fracture. Our objective was to determine which sites of previous nontraumatic fractures are most strongly associated with a diagnosis of osteoporosis, defined by a bone mineral density (BMD) T‐score of ≤ ?2.5 at the femoral neck, and an incident major osteoporotic fracture. Using administrative health databases, we conducted a retrospective historical cohort study of 39,991women age 45 years and older who had BMD testing with dual‐energy X‐ray absorptiometry (DXA). Logistic regression and Cox proportional multivariate models were used to test the association of previous fracture site with risk of osteoporosis and incident fractures. Clinical fractures at the following sites were strongly and independently associated with higher risk of an osteoporotic femoral neck T‐score after adjustment for age: hip (odds ratio [OR], 3.58; 95% confidence interval [CI], 3.04–4.21), pelvis (OR, 2.23; 95% CI, 1.66–3.0), spine (OR, 2.16; 95% CI, 1.77–2.62), and humerus (OR, 1.74; 95% CI, 1.49–2.02). Cox proportional hazards models, with adjustment for age and femoral neck BMD, showed the greatest increase in risk for a major osteoporotic fracture for women who had sustained previous fractures of the spine (hazard ratio [HR], 2.08; 95% CI, 1.72–2.53), humerus (HR, 1.70; 95% CI, 1.44–2.01), patella (HR, 1.54; 95% CI, 1.10–2.18), and pelvis (HR, 1.45; 95% CI, 1.04–2.02). In summary, our results confirm that nontraumatic fractures in women are associated with osteoporosis at the femoral neck and that the site of previous fracture impacts on future osteoporotic fracture risk, independent of BMD. © 2014 American Society for Bone and Mineral Research.     

Association of prevalent vertebral fractures, bone density, and alendronate treatment with incident vertebral fractures: effect of number and spinal location of fractures. The Fracture Intervention Trial Research Group

Vertebral fractures are the most common osteoporotic fracture and are associated with significant pain and disability. Prior vertebral fracture and low bone mineral density (BMD) are strong predictors of new vertebral fracture. Using data from 6082 women, ages 55-80 years, in the Fracture Intervention Trial (a randomized, placebo-controlled trial of the antiresorptive agent, alendronate), we explored the association of the number of prior vertebral fractures with the risk of new fractures and whether this association is influenced by the spinal location of fractures. The risk of future vertebral fractures increased with the number of prevalent fractures, independently of age and BMD; in the placebo group, more than half of the women with five or more fractures at baseline developed new vertebral fractures, compared to only 3.8% of women without prior vertebral fractures. The magnitude of association with an increased risk of future vertebral fractures was equal for prevalent fractures located in either the "lower" (T12-L4) (relative risk [RR] = 2.9; 95% CI = 1.9, 3.6) or "upper" (T4-10) spine (RR = 2.6; 95% CI = 1.9, 3.6). We found no evidence that the effectiveness of alendronate in reducing the risk of future vertebral fracture was attenuated in women with up to five or more prevalent fractures, or that it varied by the location of prevalent fractures. However, prevalent vertebral fractures in any location were more strongly associated with risk of new fractures in the upper (RR = 5.2; 95% CI = 3.2, 8.3) than in the lower spine (2.3; 1.6, 3.3). In addition, each 1 SD decrease in spinal BMD was associated with a 2.1 (1.7, 2.6) times greater odds of new fracture in the upper spine, compared with 1.5 (1.3, 1.8) for the lower spine. These findings suggest that, in older women, osteoporosis may be a stronger risk factor for new fractures in the upper (vs. lower) thoracolumbar spine, although we found no evidence that the location of prior fractures should influence treatment decisions. Physicians should recognize that prior vertebral fractures are a strong risk factor for future fractures, and consider treating such patients to reduce their risk of subsequent fractures.     

Wrist Fracture and Risk of Subsequent Fracture: Findings from the Women's Health Initiative Study

Wrist fractures are common in postmenopausal women and are associated with functional decline. Fracture patterns after wrist fracture are unclear. The goal of this study was to determine the frequency and types of fractures that occur after a wrist fracture among postmenopausal women. We carried out a post hoc analysis of data from the Women's Health Initiative Observational Study and Clinical Trials (1993–2010) carried out at 40 US clinical centers. Participants were postmenopausal women aged 50 to 79 years at baseline. Mean follow‐up duration was 11.8 years. Main measures included incident wrist, clinical spine, humerus, upper extremity, lower extremity, hip, and total non‐wrist fractures and bone mineral density (BMD) in a subset. Among women who experienced wrist fracture, 15.5% subsequently experienced non‐wrist fracture. The hazard for non‐wrist fractures was higher among women who had experienced previous wrist fracture than among women who had not experienced wrist fracture: non‐wrist fracture overall (hazard ratio [HR] = 1.40, 95% confidence interval [CI] 1.33–1.48), spine (HR = 1.48, 95% CI 1.32–1.66), humerus (HR = 1.78, 95% CI 1.57–2.02), upper extremity (non‐wrist) (HR = 1.88, 95% CI 1.70–2.07), lower extremity (non‐hip) (HR = 1.36, 95% CI 1.26–1.48), and hip (HR = 1.50, 95% CI 1.32–1.71) fracture. Associations persisted after adjustment for BMD, physical activity, and other risk factors. Risk of non‐wrist fracture was higher in women who were younger when they experienced wrist fracture (interaction p value 0.02). Associations between incident wrist fracture and subsequent non‐wrist fracture did not vary by baseline BMD category (normal, low bone density, osteoporosis). A wrist fracture is associated with increased risk of subsequent hip, vertebral, upper extremity, and lower extremity fractures. There may be substantial missed opportunity for intervention in the large number of women who present with wrist fractures. © 2015 American Society for Bone and Mineral Research.     

Low Serum DHEAS Predicts Increased Fracture Risk in Older Men: The MrOS Sweden Study

The adrenal‐derived hormones dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) are the most abundant circulating hormones and their levels decline substantially with age. DHEAS is considered an inactive precursor, which is converted into androgens and estrogens via local metabolism in peripheral target tissues. The predictive value of serum DHEAS for fracture risk is unknown. The aim of this study was, therefore, to assess the associations between baseline DHEAS levels and incident fractures in a large cohort of older men. Serum DHEAS levels were analyzed with mass spectrometry in the population‐based Osteoporotic Fractures in Men study in Sweden (n = 2568, aged 69 to 81 years). Incident X‐ray validated fractures (all, n = 594; non‐vertebral major osteoporotic, n = 255; hip, n = 175; clinical vertebral, n = 206) were ascertained during a median follow‐up of 10.6 years. DHEAS levels were inversely associated with the risk of any fracture (hazard ratio [HR] per SD decrease = 1.14, 95% confidence interval [CI] 1.05–1.24), non‐vertebral major osteoporotic fractures (HR = 1.31, 95% CI 1.16–1.48), and hip fractures (HR = 1.18, 95% CI 1.02–1.37) but not clinical vertebral fractures (HR = 1.09, 95% CI 0.95–1.26) in Cox regression models adjusted for age, body mass index (BMI) and prevalent fractures. Further adjustment for traditional risk factors for fracture, bone mineral density (BMD), and/or physical performance variables as well as serum sex steroid levels only slightly attenuated the associations between serum DHEAS and fracture risk. Similarly, the point estimates were only marginally reduced after adjustment for FRAX estimates with BMD. The inverse association between serum DHEAS and all fractures or major osteoporotic fractures was nonlinear, with a substantial increase in fracture risk (all fractures 22%, major osteoporotic fractures 33%) for those participants with serum DHEAS levels below the median (0.60 μg/mL). In conclusion, low serum DHEAS levels are a risk marker of mainly non‐vertebral fractures in older men, of whom those with DHEAS levels below 0.60 μg/mL are at highest risk. © The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.     

Relationship of body mass index with main limb fragility fractures in postmenopausal women

Body mass index (BMI) has been found to be related to the risk of osteoporotic hip fractures in women, regardless of bone mineral density (BMD). The same relationship is under debate for other limb fragility fractures. Very few studies have investigated the comparison of fracture risk among BMI categories, classified according to the WHO criteria, despite the potential usefulness of such information for clinical purposes. To address these issues we studied 2,235 postmenopausal women including those with fragility fractures of the hip (187), ankle (108), wrist (226) and humerus (85). Statistical analyses were performed by logistic regression by treating the fracture status as the dependent variable and age, age at menopause, femoral neck BMD and BMI as covariates. BMI was tested as a continuous or categorical variable. As a continuous variable, increased BMI had a protective effect against hip fracture: OR 0.949 (95% CI, 0.900–0.999), but carried a higher risk of humerus fracture: OR 1.077 (95% CI, 1.017–1.141). Among the BMI categories, only leanness: OR 3.819 (95% CI, 2.035–7.168) and obesity: OR 3.481 (95% CI, 1.815–6.678) showed a significantly higher fracture risk for hip and humerus fractures, respectively. There was no relationship between ankle and wrist fractures and BMI. In conclusion, decreasing BMI increases the risk for hip fracture, whereas increasing BMI increases the risk for humerus fractures. Leanness-related low BMD and obesity-related body instability might explain the different BMI relationships with these two types of fracture.