Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX.

A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX. INTRODUCTION: The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD). METHODS: We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted ß-coefficients. RESULTS: A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination. CONCLUSION: A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.

Update of the fracture risk prediction tool FRAX: a systematic review of potential cohorts and analysis plan.

We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. INTRODUCTION: The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors. METHODS: A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible. RESULTS: Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed. CONCLUSIONS: These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).

Zoledronic acid reduces the rate of clinical fractures after surgical repair of a hip fracture regardless of the Pretreatment bone mineral density.

In patients with surgical repair of a low-trauma hip fracture, zoledronic acid (ZA) reduced the risk of subsequent fractures regardless of pretreatment femoral neck and total hip bone mineral density (BMD). INTRODUCTION: Zoledronic acid reduces the risk of subsequent fractures after repair of a hip fracture. It is still unclear whether the benefits in fracture reduction with ZA depend upon hip bone mineral density at the time of fracture. METHODS: We preformed additional post hoc analyses of data from the HORIZON Recurrent Fracture Trial to determine if ZA treatment reduced the risk of new clinical fractures regardless of pretreatment BMD. We modeled femoral neck and total hip BMD as both continuous and dichotomous variables (BMD T-score above and below -2.5). RESULTS: There are no evidence that baseline femoral neck and total hip BMD modified the anti-fracture efficacy of ZA when pretreatment BMD was analyzed as a continuous or a dichotomous variable (interaction p-values > 0.20). The clinical fracture efficacy of ZA was similar among patients with pretreatment femoral neck BMD values above and below -2.5 (relative hazards = 0.60 and 0.67, respectively, interaction p-value = 0.95). A similar result was obtained using pretreatment total hip BMD values (relative hazards = 0.72 and 0.57, respectively, interaction p-value = 0.41). CONCLUSION: There data should provide more comfort in prescribing ZA after surgical repair of a hip fracture, regardless of pretreatment BMD.

Osteoporosis case ascertainment strategies in European and Asian countries: a comparative review.

While many clinical guidelines recommend screening for osteoporosis for early detection and treatment, there is great diversity in the case-finding strategies globally. We sought to compare case-finding strategies, focusing on the approaches used in European and Asian countries. This article provides an overview of the current case-finding strategies in the UK, Germany (including Austria and German-speaking regions of Switzerland), China, Japan, and Korea. We conducted a review of current treatment guidelines in each country and included expert opinions from key opinion leaders. Most countries define osteoporosis among patients with a radiographically identified fracture of the hip or the vertebrae. However, for other types of fractures, or in the absence of a fracture, varying combinations of risk-factor assessment and areal bone mineral density (aBMD) assessed by dual X-ray absorptiometry are used to define osteoporosis cases. A T-score ≤ - 2.5 is accepted to identify osteoporosis in the absence of a fracture; however, not all countries accept DXA alone as the sole criteria. Additionally, the critera for requiring clinical risk factors in addition to aBMD differ across countries. In most Asian countries, aBMD scanning is only provided beyond a particular age threshold. However, all guidelines recommend fracture risk assessment in younger ages if risk factors are present. Our review identified that strategies for case-finding differ regionally, particularly among patients without a fracture. More homogenized ways of identifying osteoporosis cases are needed, in both the Eastern and the Western countries, to improve osteoporosis case-finding before a fracture occurs.Case-finding in osteoporosis is essential to initiate treatment and minimize fracture risk. We identified differences in case-finding strategies between Eastern and Western countries. In the absence of a diagnosed fracture, varying combinations of risk factors and bone density measurements are used. Standardized case-finding strategies may help improve treatment rates.

Genome-wide meta-analysis of variant-by-diuretic interactions as modulators of lipid traits in persons of European and African ancestry.

Hypertension (HTN) is a significant risk factor for cardiovascular morbidity and mortality. Metabolic abnormalities, including adverse cholesterol and triglycerides (TG) profiles, are frequent comorbid findings with HTN and contribute to cardiovascular disease. Diuretics, which are used to treat HTN and heart failure, have been associated with worsening of fasting lipid concentrations. Genome-wide meta-analyses with 39,710 European-ancestry (EA) individuals and 9925 African-ancestry (AA) individuals were performed to identify genetic variants that modify the effect of loop or thiazide diuretic use on blood lipid concentrations. Both longitudinal and cross sectional data were used to compute cohort-specific interaction results, which were then combined through meta-analysis in each ancestry. These ancestry-specific results were further combined through trans-ancestry meta-analysis. Analysis of EA data identified two genome-wide significant (p < 5 × 10-8) loci with single nucleotide variant (SNV)-loop diuretic interaction on TG concentrations (including COL11A1). Analysis of AA data identified one genome-wide significant locus adjacent to BMP2 with SNV-loop diuretic interaction on TG concentrations. Trans-ancestry analysis strengthened evidence of association for SNV-loop diuretic interaction at two loci (KIAA1217 and BAALC). There were few significant SNV-thiazide diuretic interaction associations on TG concentrations and for either diuretic on cholesterol concentrations. Several promising loci were identified that may implicate biologic pathways that contribute to adverse metabolic side effects from diuretic therapy.

Large-scale pharmacogenomic study of sulfonylureas and the QT, JT and QRS intervals: CHARGE Pharmacogenomics Working Group.

Sulfonylureas, a commonly used class of medication used to treat type 2 diabetes, have been associated with an increased risk of cardiovascular disease. Their effects on QT interval duration and related electrocardiographic phenotypes are potential mechanisms for this adverse effect. In 11 ethnically diverse cohorts that included 71 857 European, African-American and Hispanic/Latino ancestry individuals with repeated measures of medication use and electrocardiogram (ECG) measurements, we conducted a pharmacogenomic genome-wide association study of sulfonylurea use and three ECG phenotypes: QT, JT and QRS intervals. In ancestry-specific meta-analyses, eight novel pharmacogenomic loci met the threshold for genome-wide significance (P<5 × 10-8), and a pharmacokinetic variant in CYP2C9 (rs1057910) that has been associated with sulfonylurea-related treatment effects and other adverse drug reactions in previous studies was replicated. Additional research is needed to replicate the novel findings and to understand their biological basis.

Pharmacogenomics study of thiazide diuretics and QT interval in multi-ethnic populations: the cohorts for heart and aging research in genomic epidemiology.

Thiazide diuretics, commonly used antihypertensives, may cause QT interval (QT) prolongation, a risk factor for highly fatal and difficult to predict ventricular arrhythmias. We examined whether common single-nucleotide polymorphisms (SNPs) modified the association between thiazide use and QT or its component parts (QRS interval, JT interval) by performing ancestry-specific, trans-ethnic and cross-phenotype genome-wide analyses of European (66%), African American (15%) and Hispanic (19%) populations (N=78 199), leveraging longitudinal data, incorporating corrected standard errors to account for underestimation of interaction estimate variances and evaluating evidence for pathway enrichment. Although no loci achieved genome-wide significance (P<5 × 10-8), we found suggestive evidence (P<5 × 10-6) for SNPs modifying the thiazide-QT association at 22 loci, including ion transport loci (for example, NELL1, KCNQ3). The biologic plausibility of our suggestive results and simulations demonstrating modest power to detect interaction effects at genome-wide significant levels indicate that larger studies and innovative statistical methods are warranted in future efforts evaluating thiazide-SNP interactions.

Effect of high-fat diet on secreted milk transcriptome in midlactation mice.

High-fat diet (HFD) during lactation alters milk composition and is associated with development of metabolic diseases in the offspring. We hypothesized that HFD affects milk microRNA (miRNA) and mRNA content, which potentially impact offspring development. Our objective was to determine the effect of maternal HFD on secreted milk transcriptome. To meet this objective, 4 wk old female ICR mice were divided into two treatments: control diet containing 10% kcal fat and HFD containing 60% kcal fat. After 4 wk on CD or HFD, mice were bred while continuously fed the same diets. On postnatal day 2 (P2), litters were normalized to 10 pups, and half the pups in each litter were cross-fostered between treatments. Milk was collected from dams on P10 and P12. Total RNA was isolated from milk fat fraction of P10 samples and used for mRNA-Seq and small RNA-Seq. P12 milk was used to determine macronutrient composition. After 4 wk of prepregnancy feeding HFD mice weighed significantly more than did the control mice. Lactose and fat concentration were significantly ( P < 0.05) higher in milk of HFD dams. Pup weight was significantly greater ( P < 0.05) in groups suckled by HFD vs. control dams. There were 25 miRNA and over 1,500 mRNA differentially expressed (DE) in milk of HFD vs. control dams. DE mRNA and target genes of DE miRNA enriched categories that were primarily related to multicellular organismal development. Maternal HFD impacts mRNA and miRNA content of milk, if bioactive nucleic acids are absorbed by neonate differences may affect development.

Spinal radiographs in those with back pain-when are they appropriate to diagnose vertebral fractures?

The presence of an osteoporotic vertebral fracture improves fracture risk assessment and may change management, so it is vital for healthcare professionals to assess patients for the presence or absence of these fractures. This may be particularly important in the presence of back pain. However, the correlation between low back symptoms and spinal imaging results is poor and the pathophysiology of most low back pain is not known, leading to a common conclusion that spinal radiographs are not appropriate for the assessment of back pain. For individual patients with back pain, spinal radiographs should be considered if they have certain features in the history and examination. As well as the traditional risk factors for osteoporosis, self-reported descriptives of back pain and novel physical examination findings have been shown to make the presence of vertebral fractures more likely. Systematic approaches have the potential to improve bone health across the population but need to be targeted to be cost-effective. Spinal radiographs should be considered for individual older patients with back pain if they have certain additional features in the history and examination.

Vertebral fracture in postmenopausal Chinese women: a population-based study.

In a random sample of postmenopausal Chinese women, the prevalence of radiographic vertebral fractures increased from 13% between ages 50 and 59 to over 50% after age 80 years. A model with seven clinical risk factors predicted the probability of vertebral fractures as well with as without BMD and better than a model with only three risk factors. More than half an hour of outdoor activity per day might correlate with lower risk of vertebral fracture in this population. INTRODUCTION: We aimed to describe the prevalence and develop a model for prediction of radiographic vertebral fractures in a large random sample of postmenopausal Chinese women. METHODS: We enrolled 1760 women from an age-stratified random sample of postmenopausal women in Beijing, China. The presence of vertebral fracture was assessed by semi-quantitative grading of lateral thoracolumbar radiographs, risk factors by interview, bone mineral density (BMD) of the proximal femur and lumbar spine by dual x-ray absorptiometry (DXA), and markers of bone turnover from a fasting blood sample. Associations of these factors were analyzed in logistic models and discrimination by areas of receiver operating characteristics curves (AUC). RESULTS: The prevalence of vertebral fracture, ranged from 13.4% ages 50 to 59 years old to 58.1% at age 80 years or older. Older age, a history of non-vertebral fracture, lower femoral neck BMD T-score, body mass index (BMI), height loss, housework, and less than half an hour of outdoor activity were significantly associated with increased probability of having a vertebral fracture. A model with those seven factors had a similar AUC with or without BMD and performed better than a simple model with three factors. CONCLUSION: This study is from a true random sample of postmenopausal women in urban China with high response rate. The prevalence of vertebral fractures in postmenopausal women in Beijing increases from 13% under age 60 to over 50% by age 80 years. A model with seven clinical risk factors with or without BMD is better than simple models and may guide the use of spine x-rays to identify women with vertebral fractures. More than half an hour of outdoor activity might correlate with lower risk of vertebral fracture in this population.

Gut microbiota of Type 1 diabetes patients with good glycaemic control and high physical fitness is similar to people without diabetes: an observational study.

AIM: Type 1 diabetes is the product of a complex interplay between genetic susceptibility and exposure to environmental factors. Existing bacterial profiling studies focus on people who are most at risk at the time of diagnosis; there are limited data on the gut microbiota of people with long-standing Type 1 diabetes. This study compared the gut microbiota of patients with Type 1 diabetes and good glycaemic control and high levels of physical-fitness with that of matched controls without diabetes. METHODS: Ten males with Type 1 diabetes and ten matched controls without diabetes were recruited; groups were matched for gender, age, BMI, peak oxygen uptake (VO2max ), and exercise habits. Stool samples were analysed using next-generation sequencing of the 16S rRNA gene to obtain bacterial profiles from each individual. Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) was implemented to predict the functional content of the bacterial operational taxonomic units. RESULTS: Faecalibacterium sp., Roseburia sp. and Bacteroides sp. were typically the most abundant members of the community in both patients with Type 1 diabetes and controls, and were present in every sample in the cohort. Each bacterial profile was relatively individual and no significant difference was reported between the bacterial profiles or the Shannon diversity indices of Type 1 diabetes compared with controls. The functional profiles were more conserved and the Type 1 diabetes group were comparable with the control group. CONCLUSIONS: We show that both gut microbiota and resulting functional bacterial profiles from patients with long-standing Type 1 diabetes in good glycaemic control and high physical fitness levels are comparable with those of matched people without diabetes.

Osteoporosis: the evolution of a diagnosis.

The global trend towards increased longevity has resulted in ageing populations and a rise in diseases or conditions that primarily affect older persons. One such condition is osteoporosis (fragile or porous bones), which causes an increased fracture risk. Vertebral and hip fractures lead to increased morbidity and mortality and result in enormous healthcare costs. Here, we review the evolution of the diagnosis of osteoporosis. In an attempt to separate patients with normal bones from those with osteoporosis and to define the osteoporosis diagnosis, multiple factors and characteristics have been considered. These include pathology and histology of the disease, the endocrine regulation of bone metabolism, bone mineral density (BMD), fracture type or trauma severity, risk models for fracture prediction, and thresholds for pharmacological intervention. The femoral neck BMD -2.5 SDs cut-off for the diagnosis of osteoporosis is arbitrarily chosen, and there is no evidence to support the notion that fracture location (except vertebral fractures) or severity is useful to discriminate osteoporotic from normal bones. Fracture risk models (including factors unrelated to bone) dissociate bone strength from the diagnosis, and treatment thresholds are often based on health-economic considerations rather than bone properties. Vertebral fractures are a primary feature of osteoporosis, characterized by decreased bone mass, strength and quality, and a high risk of another such fracture that can be considerably reduced by treatment. We believe that the 2001 definition of osteoporosis by the National Institutes of Health Consensus Development Panel on Osteoporosis is still valid and useful: 'Osteoporosis is defined as a skeletal disorder characterized by compromised bone strength predisposing a person to an increased risk of fracture'.

Evaluation of a new chromogenic medium, chromID OXA-48, for recovery of carbapenemase-producing Enterobacteriaceae from patients at a university hospital in Turkey.

The purpose of this study was to evaluate a new chromogenic medium, chromID OXA-48, for the isolation of carbapenemase-producing Enterobacteriaceae (CPE) directly from rectal swabs. chromID CARBA and chromID OXA-48 are two chromogenic media that have been commercialized for the isolation of CPE directly from clinical samples. Both media were evaluated alongside a broth enrichment method recommended by the CDC for isolation of CPE, with rectal swabs from 302 unique hospitalized patients at the Hacettepe University Hospital, Ankara, Turkey. A total of 33 patients (11 %) were found to be colonized with CPE using a combination of all methods, and all CPE produced OXA-48 carbapenemase. Klebsiella pneumoniae was by far the most dominant species of CPE and was isolated from 31 patients. Culture on chromID OXA-48 offered the highest sensitivity (75.8 %) for detection of CPE compared with the other two methods (sensitivity for both other methods was 57.6 %) and also offered the highest specificity (99.3 %). However, a combination of methods (either chromID OXA-48 plus CDC method or chromID OXA-48 plus chromID CARBA) was necessary to achieve an acceptable sensitivity (90.9 %). For isolation of CPE, in a setting where OXA-48 carbapenemase is the dominant type of carbapenemase, chromID OXA-48 is a highly useful medium but using a combination of methods is optimal for adequate detection. The combined use of two chromogenic media offered acceptable sensitivity (90.9 %) and the highest specificity (98.5 %) and also allowed for isolation of CPE within 18-20 h.

Effect of crop management and sample year on abundance of soil bacterial communities in organic and conventional cropping systems.

AIMS: To identify changes in the bacterial community, at the phylum level brought about by varied crop management. METHODS AND RESULTS: Next-generation sequencing methods were used to compare the taxonomic structure of the bacterial community within 24 agricultural soils managed with either organic or conventional methods, over a 3-year period. Relative abundance of the proportionately larger phyla (e.g. Acidobacteria and Actinobacteria) was primarily affected by sample year rather than crop management. Changes of abundance in these phyla were correlated with changes in pH, organic nitrogen and soil basal respiration. Crop management affected some of the less dominant phyla (Chloroflexi, Nitrospirae, Gemmatimonadetes) which also correlated with pH and organic N. CONCLUSION: Soil diversity can vary with changing environmental variables and soil chemistry. If these factors remain constant, soil diversity can also remain constant even under changing land use. SIGNIFICANCE AND IMPACT OF THE STUDY: The impact of crop management on environmental variables must be considered when interpreting bacterial diversity studies in agricultural soils. Impact of land use change should always be monitored across different sampling time points. Further studies at the functional group level are necessary to assess whether management-induced changes in bacterial community structure are of biological and agronomic relevance.

Low holotranscobalamin and cobalamins predict incident fractures in elderly men: the MrOS Sweden.

UNLABELLED: In a population-based study on cobalamin status and incident fractures in elderly men (n = 790) with an average follow-up of 5.9 years, we found that low levels of metabolically active and total cobalamins predict incident fractures, independently of body mass index (BMI), bone mineral density (BMD), plasma total homocysteine (tHcy), and cystatin C. INTRODUCTION: Cobalamin deficiency in elderlies may affect bone metabolism. This study aims to determine whether serum cobalamins or holotranscobalamin (holoTC; the metabolic active cobalamin) predict incident fractures in old men. METHODS: Men participating in the Gothenburg part of the population-based Osteoporotic Fractures in Men (MrOS) Sweden cohort and without ongoing vitamin B medication were included in the present study (n = 790; age range, 70-81 years). RESULTS: During an average follow-up of 5.9 years, 110 men sustained X-ray-verified fractures including 45 men with clinical vertebral fractures. The risk of fracture (adjusted for age, smoking, BMI, BMD, falls, prevalent fracture, tHcy, cystatin C, 25-OH-vitamin D, intake of calcium, and physical activity (fully adjusted)), increased per each standard deviation decrease in cobalamins (hazard ratio (HR), 1.38; 95% confidence intervals (CI), 1.11-1.72) and holoTC (HR, 1.26; 95% CI, 1.03-1.54), respectively. Men in the lowest quartile of cobalamins and holoTC (fully adjusted) had an increased risk of all fracture (cobalamins, HR = 1.67 (95% CI, 1.06-2.62); holoTC, HR = 1.74 (95% CI, 1.12-2.69)) compared with quartiles 2-4. No associations between folate or tHcy and incident fractures were seen. CONCLUSIONS: We present novel data showing that low levels of holoTC and cobalamins predicting incident fracture in elderly men. This association remained after adjustment for BMI, BMD, tHcy, and cystatin C. However, any causal relationship between low cobalamin status and fractures should be explored in a prospective treatment study.

Bone-muscle indices as risk factors for fractures in men: the Osteoporotic Fractures in Men (MrOS) Study.

OBJECTIVE: To assess bone-muscle (B-M) indices as risk factors for incident fractures in men. METHODS: Participants of the Osteoporotic Fractures in Men (MrOS) Study completed a peripheral quantitative computed tomography scan at 66% of their tibial length. Bone macrostructure, estimates of bone strength, and muscle area were computed. Areal bone mineral density (aBMD) and body composition were assessed with dual-energy X-ray absorptiometry. Four year incident non-spine and clinical vertebral fractures were ascertained. B-M indices were expressed as bone-to-muscle ratios for: strength, mass and area. Discriminative power and hazards ratios (HR) for fractures were reported. RESULTS: In 1163 men (age: 77.2±5.2 years, body mass index (BMI): 28.0±4.0 kg/m(2), 4.1±0.9 follow-up years, 7.7% of men ⋝1 fracture), B-M indices were smaller in fractured men except for bending and areal indices. Smaller B-M indices were associated with increased fracture risk (HR: 1.30 to 1.74) independent of age and BMI. Strength and mass indices remained significant after accounting for lumbar spine but not total hip aBMD. However, aBMD correlated significantly with B-M indices. CONCLUSION: Mass and bending B-M indices are risk factors for fractures in men, but may not improve fracture risk prediction beyond that provided by total hip aBMD.

Cost-effectiveness of bone densitometry among Caucasian women and men without a prior fracture according to age and body weight.

UNLABELLED: We used a microsimulation model to estimate the threshold body weights at which screening bone densitometry is cost-effective. Among women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to identify those for whom bone densitometry is cost-effective. INTRODUCTION: Bone densitometry may be more cost-effective for those with lower body weight since the prevalence of osteoporosis is higher for those with low body weight. Our purpose was to estimate weight thresholds below which bone densitometry is cost-effective for women and men without a prior clinical fracture at ages 55, 60, 65, 75, and 80 years. METHODS: We used a microsimulation model to estimate the costs and health benefits of bone densitometry and 5 years of fracture prevention therapy for those without prior fracture but with femoral neck osteoporosis (T-score ≤ -2.5) and a 10-year hip fracture risk of ≥3%. Threshold pre-test probabilities of low BMD warranting drug therapy at which bone densitometry is cost-effective were calculated. Corresponding body weight thresholds were estimated using data from the Study of Osteoporotic Fractures (SOF), the Osteoporotic Fractures in Men (MrOS) study, and the National Health and Nutrition Examination Survey (NHANES) for 2005-2006. RESULTS: Assuming a willingness to pay of $75,000 per quality adjusted life year (QALY) and drug cost of $500/year, body weight thresholds below which bone densitometry is cost-effective for those without a prior fracture were 74, 90, and 100 kg, respectively, for women aged 55, 65, and 80 years; and were 67, 101, and 108 kg, respectively, for men aged 55, 75, and 80 years. CONCLUSIONS: For women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to select those for whom bone densitometry is cost-effective.