Estimated lean mass and fat mass differentially affect femoral bone density and strength index but are not FRAX independent risk factors for fracture

The role of lipid metabolism in osteoporosis: Clinical implication and cellular mechanism

In recent years, researchers have become focused on the relationship between lipids and bone metabolism balance. Moreover, many diseases related to lipid metabolism disorders, such as nonalcoholic fatty liver disease, atherosclerosis, obesity, and menopause, are associated with osteoporotic phenotypes. It has been clinically observed in humans that these lipid metabolism disorders promote changes in osteoporosis-related indicators bone mineral density and bone mass. Furthermore, similar osteoporotic phenotype changes were observed in high-fat and high-cholesterol-induced animal models. Abnormal lipid metabolism (such as increased oxidized lipids and elevated plasma cholesterol) affects bone microenvironment homeostasis via cross-organ communication, promoting differentiation of mesenchymal stem cells to adipocytes, and inhibiting commitment towards osteoblasts. Moreover, disturbances in lipid metabolism affect the bone metabolism balance by promoting the secretion of cytokines such as receptor activator of nuclear factor-kappa B ligand by osteoblasts and stimulating the differentiation of osteoclasts. Conclusively, this review addresses the possible link between lipid metabolism disorders and osteoporosis and elucidates the potential modulatory mechanisms and signaling pathways by which lipid metabolism affects bone metabolism balance. We also summarize the possible approaches and prospects of intervening lipid metabolism for osteoporosis treatment.

Body composition in adults born preterm with very low birth weight

BACKGROUND

Studies on body composition in preterm very low birth weight (VLBW < 1500 g) survivors are inconsistent and trajectories later in life unknown. We assessed body composition and its change from young to mid-adulthood in VLBW adults.

METHODS

We studied 137 VLBW adults and 158 term-born controls from two birth cohorts in Finland and Norway at mean age 36 years. Body composition was assessed by 8-polar bioelectrical impedance. We compared results with dual-energy x-ray absorptiometry measurements at 24 years.

RESULTS

In mid-adulthood, VLBW women and men were shorter than controls. Fat percentage (mean difference in women 1.1%; 95% CI, -1.5% to 3.5%, men 0.8%; -2.0% to 3.6%) and BMI were similar. VLBW women had 2.9 (0.9 to 4.8) kg and VLBW men 5.3 (2.7 to 8.1) kg lower lean body mass than controls, mostly attributable to shorter height. Between young and mid-adulthood, both groups gained fat and lean body mass (p for interaction VLBW x age>0.3).

CONCLUSION

Compared with term-born controls, VLBW adults had similar body fat percentage but lower lean body mass, largely explained by their shorter height. This could contribute to lower insulin sensitivity and muscular fitness previously found in VLBW survivors and predispose to functional limitations with increasing age.

IMPACT

In mid-adulthood, individuals born preterm with very low birth weight had similar body fat percentage but lower lean body mass than those born at term. This was largely explained by their shorter height. First study to report longitudinal assessments of body size and composition from young to mid-adulthood in very low birth weight adults. Lower lean body mass in very low birth weight adults could contribute to lower insulin sensitivity and muscular fitness and lead to earlier functional limitations with increasing age.

An overview of the use of the fracture risk assessment tool (FRAX) in osteoporosis

FRAX®, a simple-to-use fracture risk calculator, was first released in 2008 and since then has been used increasingly worldwide. By calculating the 10-year probabilities of a major osteoporotic fracture and hip fracture, it assists clinicians when deciding whether further investigation, for example a bone mineral density measurement (BMD), and/or treatment is needed to prevent future fractures. In this review, we explore the literature around osteoporosis and how FRAX has changed its management. We present the characteristics of this tool and describe the use of thresholds (diagnostic and therapeutic). We also present arguments as to why screening with FRAX should be considered. FRAX has several limitations which are described in this review. This review coincides with the release of a version, FRAXplus, which addresses some of these limitations.

Prediction of fragility fractures in men with prostate cancer under androgen deprivation therapy: the importance of a multidisciplinary approach using a mini-invasive diagnostic tool

Bone fragility in men who are treated with androgen deprivation therapy (ADT) has a complex pathophysiology that differs from that of primary and post-menopausal osteoporosis. Fracture risk assessment based on bone mineral density (BMD) and Fracture Risk Assessment Tool (FRAX) score might not be effective in this patient setting, since high frequency of fragility fractures has been reported even in subjects with low FRAX risk and normal BMD. In this paper we want to emphasize the importance in the individual assessment of bone fragility and prediction of fractures by measuring parameters of bone quality, assessing morphometric vertebral fractures and evaluating body composition that in subjects under hormone-deprivation therapies can play a crucial role. Noteworthy, a single mini-invasive diagnostic tool, i.e., the dual energy x-ray absorptiometry (DXA) scan, offers the opportunity to evaluate reliably parameters of bone quality (e.g., trabecular bone score) and body composition, besides measurement of BMD and assessment of vertebral fractures by a morphometric approach. This article highlights the values and cost-effectiveness of this mini-invasive tool in the context of multidisciplinary approach to subjects with prostate cancer under ADTs.

Obesity and Skeletal Fragility

Skeletal fracture has recently emerged as a complication of obesity. Given the normal or better than normal bone mineral density (BMD), the skeletal fragility of these patients appears to be a problem of bone quality rather than quantity. Type 2 diabetes mellitus (T2DM), the incidence of which increases with increasing body mass index, is also associated with an increased risk for fractures despite a normal or high BMD. With the additional bone pathology from diabetes itself, patients with both obesity and T2DM could have a worse skeletal profile. Clinically, however, there are no available methods for identifying those who are at higher risk for fractures or preventing fractures in this subgroup of patients. Weight loss, which is the cornerstone in the management of obesity (with or without T2DM), is also associated with an increased risk of bone loss. This review of the literature will focus on the skeletal manifestations associated with obesity, its interrelationship with the bone defects associated with T2DM, and the available approach to the bone health of patients suffering from obesity.

Diet-Stimulated Marrow Adiposity Fails to Worsen Early, Age-Related Bone Loss

INTRODUCTION

Longitudinal effect of diet-induced obesity on bone is uncertain. Prior work showed both no effect and a decrement in bone density or quality when obesity begins prior to skeletal maturity. We aimed to quantify long-term effects of obesity on bone and bone marrow adipose tissue (BMAT) in adulthood.

METHODS

Skeletally mature, female C57BL/6 mice (n = 70) aged 12 weeks were randomly allocated to low-fat diet (LFD; 10% kcal fat; n = 30) or high-fat diet (HFD; 60% kcal fat; n = 30), with analyses at 12, 15, 18, and 24 weeks (n = 10/group). Tibial microarchitecture was analyzed by µCT, and volumetric BMAT was quantified via 9.4T MRI/advanced image analysis. Histomorphometry of adipocytes and osteoclasts, and qPCR were performed.

RESULTS

Body weight and visceral white adipose tissue accumulated in response to HFD started in adulthood. Trabecular bone parameters declined with advancing experimental age. BV/TV declined 22% in LFD (p = 0.0001) and 17% in HFD (p = 0.0022) by 24 weeks. HFD failed to appreciably alter BV/TV and had negligible impact on other microarchitecture parameters. Both dietary intervention and age accounted for variance in BMAT, with regional differences: distal femoral BMAT was more responsive to diet, while proximal femoral BMAT was more attenuated by age. BMAT increased 60% in the distal metaphysis in HFD at 18 and 24 weeks (p = 0.0011). BMAT in the proximal femoral diaphysis, unchanged by diet, decreased 45% due to age (p = 0.0002). Marrow adipocyte size via histomorphometry supported MRI quantification. Osteoclast number did not differ between groups. Tibial qPCR showed attenuation of some adipose, metabolism, and bone genes. A regulator of fatty acid β-oxidation, cytochrome C (CYCS), was 500% more abundant in HFD bone (p < 0.0001; diet effect). CYCS also increased due to age, but to a lesser extent. HFD mildly increased OCN, TRAP, and SOST.

CONCLUSIONS

Long-term high fat feeding after skeletal maturity, despite upregulation of visceral adiposity, body weight, and BMAT, failed to attenuate bone microarchitecture. In adulthood, we found aging to be a more potent regulator of microarchitecture than diet-induced obesity.

Relationships between longitudinal changes in body composition and bone mineral density in middle-to-older aged Australians

There are limited longitudinal data regarding relationships between changes in body composition and bone mineral density (BMD). In 3671 participants aged 46-70 years at baseline, ∆lean mass was a stronger determinant than ∆fat mass of ∆BMD over 6 years. Maintained or increased lean mass may slow down age-related bone loss.

PURPOSE

There are limited longitudinal data regarding relationships between changes in body composition and bone mineral density (BMD) with ageing. We examined these in the Busselton Healthy Ageing Study.

METHODS

We studied 3671 participants (2019 females) aged 46-70 years at baseline with body composition and BMD assessments by dual-energy x-ray absorptiometry at baseline and after ~6 years. Relationships between changes in total body mass (∆TM), lean mass (∆LM) and fat mass (∆FM) with ∆BMD at total hip, femoral neck and lumbar spine were evaluated using restricted cubic spline modelling (accounting for baseline covariates) and mid-quartile least square means were compared.

RESULTS

∆TM was positively associated with ∆BMD of total hip and femoral neck in both sexes, and spine in females; in females but not males, associations plateaued at ∆TM above ~5kg for all sites. In females, ∆LM was positively associated with ∆BMD of all three sites with plateauing of the relationship at ∆LM above ~1kg. Women in the highest quartile of ∆LM (Q4, mid-quartile value +1.6 kg) had 0.019-0.028 g/cm2 less reduction in BMD than those in the lowest quartile (Q1, -2.1 kg). In males, ∆LM was positively associated with ∆BMD of total hip and femoral neck; men in Q4 (+1.6 kg) had 0.015 and 0.011 g/cm2 less bone loss, respectively, compared with Q1 (-2.7 kg). ∆FM was positively associated with ∆BMD of total hip only in both sexes.

CONCLUSION

∆LM is a stronger determinant than ∆FM of ∆BMD. Maintained or increased LM is associated with less age-related bone loss.

Associations of Type 2 Diabetes, Body Composition, and Insulin Resistance with Bone Parameters: The Dubbo Osteoporosis Epidemiology Study

Type 2 diabetes (T2D) may be associated with increased risk of fractures, despite preserved bone mineral density (BMD). Obesity and insulin resistance (IR) may have separate effects on bone turnover and bone strength, which contribute to skeletal fragility. We characterized and assessed the relative associations of obesity, body composition, IR, and T2D on bone turnover markers (BTMs), BMD, and advanced hip analysis (AHA). In this cross-sectional analysis of Dubbo Osteoporosis Epidemiology Study, 525 (61.3% women) participants were grouped according to T2D, IR (homeostasis model assessment insulin resistance [HOMA-IR] Collapse

Key Words

• BIOCHEMICAL MARKERS OF BONE TURNOVER
• BONE‐FAT INTERACTIONS
• DUAL‐ENERGY X‐RAY ABSORPTIOMETRY
• FRACTURE RISK ASSESSMENT
• STATISTICAL METHODS

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MESH Headings Collapse

Grants

• St. Vincent's Clinic Foundation

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Affiliation(s) Collapse

Visceral Adipose Tissue is Negatively Associated With Bone Mineral Density in NHANES 2011-2018

Context

The relationship of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) with bone mineral density (BMD) is not well established.

Objective

To examine the associations of VAT and SAT with total body BMD in a large, nationally representative population with a wide range of adiposity.

Methods

We analyzed 10 641 subjects aged 20 to 59 years in National Health and Nutrition Examination Survey 2011-2018 who had undergone total body BMD and had VAT and SAT measured by dual-energy X-ray absorptiometry. Linear regression models were fitted while controlling for age, sex, race or ethnicity, smoking status, height, and lean mass index.

Results

In a fully adjusted model, each higher quartile of VAT was associated with an average of 0.22 lower T-score (95% CI, -0.26 to -0.17, P < 0.001), whereas SAT had a weak association with BMD but only in men (-0.10; 95% CI, -0.17 to -0.04, P = 0.002). However, the association of SAT to BMD in men was no longer significant after controlling for bioavailable sex hormones. In subgroup analysis, we also found differences in the relationship of VAT to BMD in Black and Asian subjects, but these differences were eliminated after accounting for racial and ethnic differences in VAT norms.

Conclusions

VAT has a negative association with BMD. Further research is needed to better understand the mechanism of action and, more generally, to develop strategies for optimizing bone health in obese subjects.

Increased fat mass negatively influences femoral neck bone mineral density in men but not women

BACKGROUND

Obesity is known to be a protective factor against osteoporosis. However, recent studies have shown that excessive adiposity may be detrimental for bone health.

OBJECTIVE

To determine the association of lean mass (LM) and fat mass (FM) with bone mineral density (BMD) in Thais.

METHODS

Bone density studies of consecutive patients of Srinagarind Hospital, Khon Kaen, Thailand between 2010 and 2015 were reviewed. LM, FM, lumbar spine (LS) and femoral neck (FN) BMD were measured. Lean mass index (LMI) and fat mass index (FMI) were calculated [LMI=LM (kg)/height (m)², FMI=FM (kg)/height (m)²] and analyzed to determine the association with LS and FN BMD using multiple regression analysis. This study was approved by the institutional ethical committee (HE42116).

RESULTS

A total of 831 participants were included. The mean ± SD age was 50.0 ± 16.3 years. In men, LMI (per 1 kg/m² increase) was positively correlated with FN BMD (g/cm², β 0.033) and LS BMD (g/cm², β 0.031), after adjusting for age, height and FMI. Whereas FMI (per 1 kg/m² increase) was negatively correlated with FN BMD (g/cm², β -0.015) but not with LS BMD (g/cm², β 0.005) after adjusting for age, height and LMI. In women, both LMI and FMI were positively correlated with LS BMD (g/cm², LMI: β 0.012; FMI: β 0.016) and FN BMD (g/cm², LMI: β 0.034; FMI: β 0.007) with age, height, LMI and FMI included in the model.

CONCLUSION

Our findings indicate that FM has a sex-specific influence on BMD in Thais.

Malnutrition in Older Adults—Effect on Falls and Fractures: A Narrative Review

Malnutrition in older adults impacts health status, increased mortality, and morbidity. Malnutrition may increase the development of geriatric syndromes and contribute to a higher prevalence of falls and osteoporotic fractures that lead to loss of independence and an increased rate of institutionalization. The role of malnutrition in the pathogenesis of other geriatric syndromes seems to be well established. However, the data concerning nutritional interventions are confounding. Moreover, long-term undernutrition seems to be one of the factors that strongly influences the efficacy of interventions. This review outlines the current literature on this topic, and aims to guide physicians to make proper decisions to prevent the vicious cycle of falls, fractures, and their negative outcomes in patients with malnutrition.

Obesity and Bone Health: A Complex Relationship

Recent scientific evidence has shown an increased risk of fractures in patients with obesity, especially in those with a higher visceral adipose tissue content. This contradicts the old paradigm that obese patients were more protected than those with normal weight. Specifically, in older subjects in whom there is a redistribution of fat from subcutaneous adipose tissue to visceral adipose tissue and an infiltration of other tissues such as muscle with the consequent sarcopenia, obesity can accentuate the changes characteristic of this age group that predisposes to a greater risk of falls and fractures. Other factors that determine a greater risk in older subjects with obesity are chronic proinflammatory status, altered adipokine secretion, vitamin D deficiency, insulin resistance and reduced mobility. On the other hand, diagnostic tests may be influenced by obesity and its comorbidities as well as by body composition, and risk scales may underestimate the risk of fractures in these patients. Weight loss with physical activity programs and cessation of high-fat diets may reduce the risk. Finally, more research is needed on the efficacy of anti-osteoporotic treatments in obese patients.

Fat Mass Has Negative Effects on Bone, Especially in Men: A Cross-sectional Analysis of NHANES 2011-2018

CONTEXT

The effect of high levels of obesity on bone health are not clear.

OBJECTIVE

We aimed to examine the associations of body composition and bone mineral density (BMD) in a large, nationally representative population with a wide range of body mass index.

METHODS

We analyzed 10 814 subjects aged 20-59 from NHANES 2011-2018 who had total body BMD and body composition data. Body composition was examined as lean mass index (LMI) and fat mass index (FMI). Linear regression models were created with BMD as the outcome, while examining LMI and FMI and controlling for age, gender, race/ethnicity, height, and smoking status.

RESULTS

In multivariable modeling, every 1 kg/m2 additional LMI was associated with 0.19 higher T-score, while every additional 1 kg/m2 in FMI was associated with 0.10 lower T-score (P < .001 for both). The negative association of FMI with BMD was mainly seen when adjusting for LMI. Effects of LMI were similar in men and women, but the effect of FMI was more negative in men (0.13 lower T-score per additional 1 kg/m2 of FMI in men vs 0.08 lower BMD T-score in women, P for interaction < .001).

CONCLUSION

In subjects under 60 years old, lean mass had a strong positive association with BMD. Conversely, fat mass had a moderate, negative association with BMD that was most notable in men at high levels of fat. Our results emphasize the importance of bone health in obesity and may explain site-specific increases in fracture rates in some studies of obese subjects.

Assessment and treatment of osteoporosis and fractures in type 2 diabetes

There is substantial, and growing, evidence that type 2 diabetes (T2D) is associated with skeletal fragility, despite often preserved bone mineral density. As post-fracture outcomes, including mortality, are worse in people with T2D, bone management should be carefully considered in this highly vulnerable group. However, current fracture risk calculators inadequately predict fracture risk in T2D, and dedicated randomised controlled trials identifying optimal management in patients with T2D are lacking, raising questions about the ideal assessment and treatment of bone health in these people. We synthesise the current literature on evaluating bone measurements in T2D and summarise the evidence for safety and efficacy of both T2D and anti-osteoporosis medications in relation to bone health in these patients.

The Relationship Between Bone Mineral Density and Body Composition Among Qatari Women With High Rate of Obesity: Qatar Biobank Data

Studies have reported inconsistent results for the relationship between body composition and bone mineral density (BMD) among women, especially those with a high rate of obesity. This study aims to examine the association between BMD and body composition among Qatari women. A cross-sectional study, using data from the Qatar Biobank (QBB), was conducted on 2,000 Qatari women aged 18 and over. Measurements were taken by dual-energy X-ray absorptiometry (DEXA) for body composition [visceral fat and android fat (AF)], gynoid fat (GF), trunk fat, total fat mass (TFM), total lean mass (LM) and bone mineral density (BMD), including the lumber spine, neck, femur and total body. The participants were divided into groups of normal and low BMD, based on their T-score. Non-linear regression analysis using the restricted cubic spline method was performed according to the T-score of the total BMD for the fat mass variables. Women with a low BMD (T-score <-1) had significantly lower body composition indicators. LM was positively correlated with BMD at the spine (r = 0.29, p < 0.001), neck (r = 0.32, p < 0.001), and femur (r = 0.28, p < 0.001), as well as total BMD (r = 0.29, p < 0.001) and T-score (r = 0.31, p < 0.001), while the correlatio between TFM and BMD was negative and weak (r = -0.05, <0.017). Results of the non-linear regression indicated that components of fat distribution (TFM, AF, GF and trunk fat) were positively associated with total body T-score. In the adjusted non-liner regression, only a slight increase in T-score was recorded with an increase in FM. The association between FM and BMD was non-linear, suggesting that FM may not be a strong protector of bones among women with high rate of obesity.

UK clinical guideline for the prevention and treatment of osteoporosis

The National Osteoporosis Guideline Group (NOGG) has revised the UK guideline for the assessment and management of osteoporosis and the prevention of fragility fractures in postmenopausal women, and men age 50 years and older. Accredited by NICE, this guideline is relevant for all healthcare professionals involved in osteoporosis management.

INTRODUCTION

The UK National Osteoporosis Guideline Group (NOGG) first produced a guideline on the prevention and treatment of osteoporosis in 2008, with updates in 2013 and 2017. This paper presents a major update of the guideline, the scope of which is to review the assessment and management of osteoporosis and the prevention of fragility fractures in postmenopausal women, and men age 50 years and older.

METHODS

Where available, systematic reviews, meta-analyses and randomised controlled trials were used to provide the evidence base. Conclusions and recommendations were systematically graded according to the strength of the available evidence.

RESULTS

Review of the evidence and recommendations are provided for the diagnosis of osteoporosis, fracture-risk assessment and intervention thresholds, management of vertebral fractures, non-pharmacological and pharmacological treatments, including duration and monitoring of anti-resorptive therapy, glucocorticoid-induced osteoporosis, and models of care for fracture prevention. Recommendations are made for training; service leads and commissioners of healthcare; and for review criteria for audit and quality improvement.

CONCLUSION

The guideline, which has received accreditation from the National Institute of Health and Care Excellence (NICE), provides a comprehensive overview of the assessment and management of osteoporosis for all healthcare professionals involved in its management. This position paper has been endorsed by the International Osteoporosis Foundation and by the European Society for the Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases.

Retrospective Analysis of Factors Associated with Fracture in 714 Patients with Polymyalgia Rheumatica

Introduction

Polymyalgia rheumatica (PMR) is a disease of the elderly, associated with increased fracture risk due to glucocorticosteroid (GC) treatment with the additional possible influence of chronic inflammation. Risk factors for fracture in PMR have not been extensively studied. Hip structure analysis (HSA) is a way to measure bone morphology in the hip using dual X-ray absorptiometry (DEXA). It has been used as a predictor of fracture in epidemiological settings. HSA has not been studied in PMR before.

Objectives

The object of this retrospective study was to determine if fracture risk in PMR was associated with densitometry data and to determine the influence, if any, of HSA on that association.

Methods

714 patients with PMR referred for a bone density estimate at a district general hospital from June 2004 to October 2010 were studied. Demographic data, GC use, alcohol consumption, smoking status, secondary osteoporosis, and fracture history were recorded. Bone mineral density (BMD), Z score, T score, body composition data, and HSA measurements were collected. These were geometric measurements taken from 2-dimensional DEXA images of the hip. Fracture was modelled as an outcome variable using logistic regression models, adjusted for age and sex. And the fit of the model was assessed by comparing the area under the curve (AUC).

Results

714 patients were studied, 532 (75%) were female, and mean age was 70.5 with SD of 8.8. 703 (98%) had been treated with GCs. Lumbar and femoral BMD models were significantly associated with fracture. Right femur OR 0.062 (0.014-0.285), left femur OR 0.098 (0.023-0.412), right femoral neck 0.078 (0.014-0.43), left femoral neck 0.104 (0.022-0.492), L1 0.192 (0.066-0.56), L2 OR 0.138 (0.053-0.358), L3 0.192 (0.079-0.463), and L4 0.243 (0.108-0.544). Cross-sectional area was the only HSA parameter that was associated with fracture OR 0.988 (0.980–0.997).

Conclusion

L2 association models were strongest. Prospective studies are needed to elucidate whether these factors predict future fracture. GC data were binary, not reflecting dose and duration.

The Relationship between Body Composition and Bone Mineral Density of Female Workers in A Unit of Tai’an

Objective. To explore the relationship between body composition and bone mineral density (BMD) of female workers in a university of Tai’an. Methods. This study randomly selected 90 female employees in a university of Tai’an. The body composition was monitored by body composition analyzer (inbody770), and the lumbar bone mineral density was monitored by dual energy X-ray absorptiometry (BMD model). The data were analyzed by SPSS 22.0 statistical software. Results. With the increasing of body mass index (BMI), BMD of female lumbar spines 1-4 (L1-4) increased gradually. Spearman correlation analysis showed that BMI, skeletal muscle mass, upper limb muscle mass, trunk muscle mass, lower limb muscle mass, and whole-body phase angle were positively correlated with L1-4BMD. Age was negatively correlated with L1-4BMD. Linear regression analysis showed that age was a negative factor of L1-4BMD, and skeletal muscle mass was a protective factor of abnormal bone mass, especially lower limb muscle mass. Conclusions. Lower limb muscle mass is a protective factor of female BMD. Strengthening physical exercise to improve lower limb muscle mass is conducive to the prevention of female osteoporosis.

Anthropometric and Body Composition Measurements Related to Osteoporosis in Geriatric Population

Objective:

This study aimed to evaluate different anthropometric and body composition measurements, including weight, body mass index (BMI), body fat percentage (fat%), skeletal muscle index (SMI), a body shape index (ABSI), waist circumference (WC), and hip circumference (HC), in relation to bone mineral density.

Methods:

This is a cross-sectional study of a total of 482 patients who consulted the geriatric outpatient clinic between 2018 and 2019. Patients were evaluated with dual-energy X-ray absorptiometry. Anthropometric measurements (HC, WC, weight, BMI, and ABSI), as well as body composition analysis (fat% and SMI) by bioimpedance analysis system, were performed. The patients were evaluated with the rapid Assessment of Physical Activity Index in terms of aerobic exercise habits.

Results:

There was a significant correlation between lumbar spine (LS) T-score and SMI (r=0.36, p=0.000) and between LS T-score and weight (r=0.21, p=0.000), BMI (r=0.10, p=0.045) and WC (r=0.15, p=0.001). There was a statistically significant correlation between femur neck (FN) T-score and fat% (r=0.15, p=0.001), SMI (r=0.15, p=0.010), weight (r=0.22, p=0.000), BMI (r=0.20, p=0.000), WC (r=0.14, p=0.003), and HC (r=0.17, p=0.001). There was no statistically significant correlation between physical activity and LS T-score (n=353, r=0.08, p=0.16) and FN T-score (n=360, r=0.03, p=0.53). In multiple regression analysis, SMI contributes most in predicting FN and LS T-scores.

Conclusions:

Anthropometric measurements should be carefully selected in the geriatric population. Among the measurements, the strongest relationship was found between LS T-score and SMI.

Prior loss of body mass index, low body mass index, and central obesity independently contribute to higher rates of fractures in elderly women and men

We aimed to comprehensively evaluate the association of body composition with fracture risk using longitudinal data from a Swedish cohort of 44,366 women and men (mean age of 70 years) and a subcohort of 5022 women. We estimated hazard ratios (HRs) of fracture for baseline body mass index (BMI), BMI change during the prior 12 and 18 years, baseline waist-to-height ratio, total and regional distribution of fat and lean mass, with and without areal bone mineral density (BMD) adjustment. During follow-up (median 8.7 years), 7290 individuals sustained a fracture, including 4279 fragility fractures, of which 1813 were hip fractures. Higher baseline BMI and prior gain in BMI were inversely associated with all types of fracture. Lower fracture rate with higher baseline BMI was seen within every category of prior BMI change, whereas higher prior BMI gain conferred a lower rate of fracture within those with normal baseline BMI. Each standard deviation (SD) higher baseline waist-to-height ratio, after adjustment for BMI, was associated with higher rates of hip fracture in both women and men (HR 1.12; 95% CI, 1.05-1.19). In the subcohort (median follow-up 10 years), higher baseline fat mass index (FMI) and appendicular lean mass index (LMI) showed fracture-protective effects. After BMD adjustment, higher baseline BMI, total LMI, FMI, and higher prior BMI gain were associated with higher fracture rate. Baseline fat distribution also was associated with fracture rate; a 1-SD higher android to gynoid fat mass ratio in prior BMI gainers was associated with BMD-adjusted HRs of 1.16 (95% CI, 1.05-1.28) for any fracture and 1.48 (95% CI, 1.16-1.89) for hip fracture. This pattern was not observed among prior BMI losers. These findings indicate that for optimal fracture prevention, low baseline BMI, prior BMI loss and high baseline central obesity should be avoided in both women and men. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Does the Severity of Obesity Influence Bone Mineral Density Values in Premenopausal Women?

The aim of this study was to compare bone mineral content (BMC), bone mineral density (BMD), and geometric indices of hip bone strength among 3 groups of adult obese premenopausal women (severely obese, morbidly obese, and super morbidly obese). This study included 65 young adult premenopausal women whose body mass index (BMI) > 35 kg/m². They were divided into 3 groups using international cut-offs for BMI. Body composition and bone variables were measured by DXA. DXA measurements were completed for the whole body (WB), lumbar spine, total hip (TH), and femoral neck (FN). Geometric indices of FN strength (cross-sectional area, cross-sectional moment of inertia [CSMI], section modulus [Z], strength index [SI], and buckling ratio) were calculated by DXA. Results showed that age and height were not significantly different among the 3 groups. WB BMC values were higher in super morbidly obese women compared to severely and morbidly obese women. WB BMD, L1-L4 BMD, total hip BMD, FN BMD, cross-sectional area, CSMI, Z, and buckling ratio values were not significantly different among the 3 groups. SI values were lower in super morbidly obese compared to morbidly and severely obese women. In the whole population (n = 65), body weight, BMI, lean mass, fat mass, and trunk fat mass were positively correlated to WB BMC and negatively correlated to SI. Weight and lean mass were positively correlated to WB BMD and CSMI. Our findings suggest that the severity of obesity does not influence BMD values in premenopausal women.

Risk Factors for Incident Falls and Fractures in Older Men With and Without Type 2 Diabetes Mellitus: The Concord Health and Ageing in Men Project

BACKGROUND

Type 2 diabetes mellitus (T2DM) increases falls and fracture risk. Our objective was to compare incidence and risk factors for falls and fractures in community-dwelling older men with and without T2DM.

METHODS

A total of 1705 men (471 with T2DM; 1234 without T2DM) aged ≥70 years were assessed at baseline. Men were contacted every 4 months for 6.0 ± 2.2 years to ascertain incident falls and fractures, with the latter being confirmed by radiographic reports. Hip fractures were ascertained via data linkage (follow-up: 8.8 ± 3.6 years). Risk factors for falls and fractures included physical activity and function, body composition, medications, and vision measures.

RESULTS

Men with T2DM had similar fall (incident rate ratio [IRR]: 0.92 [95% confidence interval {CI}: 0.70, 1.12], n = 1246) and fracture rates (hazard ratio [HR]: 0.86 [95% CI: 0.56, 1.32], n = 1326) compared to men without T2DM after adjustment for significant risk factors. In men with T2DM, depression (IRR: 1.87 [95% CI: 1.05, 3.34], n = 333), sulphonylurea usage (IRR: 2.07 [95% CI: 1.30, 3.27]) and a greater number of prescription medications (IRR: 1.13 [95% CI: 1.03, 1.24]) were independently associated with increased fall rates, and higher total hip bone mineral density was independently associated with lower fracture rates (HR: 0.63 [95% CI: 0.47, 0.86], n = 351). Interaction terms demonstrated that better contrast sensitivity was independently associated with lower fracture rates (HR: 0.14 [95% CI: 0.02, 0.87]) in men with T2DM compared to men without T2DM.

CONCLUSION

Fall and fracture rates were similar in men with and without T2DM after adjusting for significant risk factors. Vision assessments including contrast sensitivity measures may improve fracture prediction in older men with T2DM.

Relationships between anthropometric adiposity indexes and bone mineral density in a cross-sectional Chinese study

BACKGROUND CONTEXT

Previous studies have reported conflicting results for the relationships between anthropometric adiposity indexes and bone mineral density, based on dual-energy X-ray absorptiometry (DXA). However, few studies were published based on quantitative computed tomography (QCT), especially for Chinese population.

PURPOSE

To evaluate the associations of spine bone mineral density (BMD) with body mass index (BMI), waist circumstance (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and a body shape index (ABSI) using QCT.

STUDY DESIGN/SETTING

A Cross-sectional study.

PATIENT SAMPLE

Around 3,457 participants in multiple communities across 7 administrative regions of China.

OUTCOME MEASURES

Spine BMD was measured using QCT, and the classification of osteoporosis was defined as follows: 1) osteoporosis if BMD <80mg/cm³, 2) osteopenia if BMD 80-119 mg/cm³, and 3) normal bone mass if BMD≥120 mg/cm³.

METHODS

This study was conducted using convenient sampling between 2013 and 2017. Multivariable linear regression model and logistic regression models were used for the associations of continuous and categorical BMD, respectively.

RESULTS

Around 3,405 participants were included in the final analyses, including 1,272 males and 2,133 females, with spine BMD of 111.00±35.47 mg/cm³ and 99.38±40.60 mg/cm³, respectively. Spine BMD decreased significantly with the increase of ABSI in females (adjusted β, -5.74; 95% confidence interval [CI], -8.50 to -2.98), and this trend also was kept in females aged at less than 60 years (adjusted β, -14.54; 95% CI, -20.40 to -8.68), and females with age ≥60 years (adjusted β, -7.59; 95% CI, -10.91 to -4.28). However, this inverse association was observed only in males with age ≥ 60 years (adjusted β, -5.19; 95% CI, -10.08 to -0.29). Except ABSI, negative associations of Spine BMD with WC (adjusted β, -0.46; 95% CI, -0.77 to -0.15), WHR (adjusted β, -6.25; 95% CI, -10.63 to -1.86), WHtR (adjusted β, -6.80; 95% CI, -11.63 to -1.97) were shown in females aged at <60 years, and positive association with BMI in males with age ≥60 years (adjusted β, 0.92; 95% CI, 0.29-1.55).

CONCLUSIONS

ABSI had more remarkable association with spine BMD, compared with the other four indexes.

Fracture prediction from FRAX for Canadian ethnic groups: a registry-based cohort study

We identified large between-ethnicity calibration differences in the Canadian FRAX® tool which substantially overestimated the major osteoporotic fracture (MOF) risk in Asian women and Black women, and overestimated hip fracture risk in Asian women.

PURPOSE

FRAX® is calibrated using population-specific fracture and mortality data. The need for FRAX to accommodate ethnic diversity within a country is uncertain. We addressed this question using the population-based Manitoba Bone Mineral Density (BMD) Program registry and self-reported ethnicity.

METHODS

The study population was women aged 40 years or older with baseline FRAX assessments (Canadian and other ethnic calculators), fracture outcomes, and self-reported ethnicity (White N = 68,907 [referent], Asian N = 1910, Black N = 356). Adjusted hazard ratios (HR) with 95% confidence intervals (CI) for time to MOF and hip fracture were estimated. We examined candidate variables from DXA that might contribute to ethnic differences including skeletal size, hip axis length (HAL), trabecular bone score (TBS), and estimated body composition.

RESULTS

Adjusted for baseline risk using the Canadian FRAX tool with BMD, Asian women compared with White women were at much lower risk for MOF (HR 0.46, 95% CI 0.35-0.59) and hip fracture (0.16, 95% CI 0.08-0.34). Black women were also at lower MOF risk (HR 0.58, 95% CI 0.32-1.00); there were no hip fractures. The US ethnic-specific FRAX calculators accounted for most of the between-ethnicity differences in MOF risk (86% for Asian, 92% for Black) but only partially accounted for lower hip fracture risk in Asian women (40%). The candidate variables explained only a minority of the effect of ethnicity. Gradient of risk in analyses was similar (p-interactions ethnicity*FRAX non-significant).

CONCLUSIONS

We identified significant ethnic differences in performance of the Canadian FRAX tool with fracture probability overestimated among Asian and Black women. The US ethnic calculators helped to address this discrepancy for MOF risk assessment, but not for hip fracture risk among Asian women.

Association between Bone Mineral Density and Nutritional Status, Body Composition and Bone Metabolism in Older Adults

PURPOSE

To identify an association between bone mineral density (BMD) and nutritional status, body composition and bone metabolism in older patients.

METHODS

Cross-sectional study, involving older adults, with osteopenia/osteoporosis and with normal BMD. The mineral density of the lumbar spine from L1 to L4 and the proximal region of the femur was assessed using dual energy X-ray absorptiometry. Biochemical analyzes were performed of 25(OH)-D, calcium and parathormone. Weight, knee height, and abdominal (AC), mid-upper arm (MUAC) and calf (CC) circumferences were measured. The percentage of body fat (%BF) and Fat-Free Mass (FFM) were quantified by electrical bioimpedance analysis. The Body Mass Index (BMI) was calculated. The statistical analysis used bivariate and multivariate, parametric and/or non-parametric tests, and was considered significant when p <0.05.

RESULTS

Of the total 51 older adults assessed, 30 of them (58.8%) were diagnosed with osteopenia/osteoporosis. Body weight (p = 0.001), BMI (p = 0.001), % BF (p = 0.030) and serum concentrations of 25(OH)-D (p = 0.003) were higher in the group without changes in BMD. BMI and serum levels of 25(OH)-D demonstrated a positive correlation with the BMD of all bone compartments and the AC displayed a positive correlation with the lumbar vertebrae. In the logistic regression models, adjusted for sex and age, the BMI and the serum concentration of 25(OH)-D were presented as a protective factor against osteopenia/osteoporosis.

CONCLUSIONS

Higher body weight, BMI, AC and %BF, and sufficient serum levels of vitamin D, were shown to be promoters of BMD.

Incidence and predictors of fractures in older adults with and without obesity defined by body mass index versus body fat percentage

PURPOSE

The aim of this study was to determine and compare risk factors associated with incident fractures in older adults with and without obesity, defined by both body mass index (BMI) and body fat percentage.

METHODS

1,099 older adults (mean ± standard deviation age = 63.0 ± 7.5) years, participated in this prospective cohort study. Obesity status at baseline was defined by BMI (≥30 kg/m²) obtained by anthropometry and body fat percentage (≥30% for men and ≥40% for women) assessed by dual-energy X-ray absorptiometry (DXA). Total hip and lumbar spine areal bone mineral density (aBMD) were assessed by DXA up to five years. Incident fractures were self-reported up to 10 years.

RESULTS

Prevalence of obesity was 28% according to BMI and 43% according to body fat percentage. Obese older adults by BMI, but not body fat percentage, had significantly higher aBMD at the total hip and spine compared with non-obese (both p-value<0.05). Obese older adults by body fat percentage had significantly higher likelihood of all incident fractures (OR: 1.71; CI:1.08, 2.71) and non-vertebral fractures (OR: 1.88; CI:1.16, 3.04) compared with non-obese after adjusting for confounders. Conversely, obese older adults by BMI had a significantly lower likelihood (OR: 0.54; CI:0.31, 0.94) of non-vertebral fractures although this was no longer significant after adjustment for total hip aBMD (all p-value > 0.05). Mediation analysis confirmed that aBMD meditated the effects of BMI, but not body fat percentage, on all incident fractures. Higher baseline falls risk score was the only consistent predictor of increased likelihood of incident fracture in obese individuals only, according to both BMI and body fat percentage (both p-value<0.05).

CONCLUSIONS

Obesity defined by body fat percentage is associated with increased likelihood of incident fractures in community-dwelling older adults, whereas those who are obese according to BMI have reduced likelihood of incident fracture which appears to be explained by higher aBMD. Falls risk assessment may improve identification of obese older adults at increased risk of incident fractures.

Adiposity Without Obesity: Associations with Osteoporosis, Sarcopenia, and Falls in the Healthy Ageing Initiative Cohort Study

OBJECTIVE

Obesity is commonly defined by BMI rather than adiposity, which may have differential effects on musculoskeletal health. Musculoskeletal outcomes were compared in older adults with normal adiposity and normal BMI (NA-NBMI), those with high adiposity but normal BMI (HA-NBMI), and those with high adiposity and high BMI (HA-HBMI).

METHODS

In 3,411 70-year-olds, obesity was defined as BMI ≥ 30 kg/m² and adiposity as body fat percentage ≥ 25% (men) or ≥ 35% (women) from dual-energy x-ray absorptiometry. Bone parameters were measured by dual-energy x-ray absorptiometry and peripheral quantitative computed tomography. Sarcopenia was defined as low handgrip strength with or without low appendicular lean mass. Falls were self-reported 6 and 12 months later.

RESULTS

Prevalence of NA-NBMI, HA-NBMI, and HA-HBMI was 14.2%, 68.1%, and 17.7%, respectively. Compared with HA-HBMI, HA-NBMI had increased likelihood for sarcopenia (adjusted odds ratio: 3.99; 95% CI: 1.41-11.32) and osteoporosis (2.91; 95% CI: 2.35-3.61) but similar likelihood of falls (P > 0.05). HA-NBMI had lower values for bone geometry parameters, as well as grip strength, than both NA-NBMI and HA-HBMI (all P < 0.05).

CONCLUSIONS

High adiposity without high BMI is more common than BMI-defined obesity in older Swedish adults but does not provide similar protection from osteoporosis and sarcopenia.

Influence of Physical Activity Level on Composite Indices of Femoral Neck Strength in a Group of Young Overweight Men

The aim of the present study was to explore the influence of physical activity level on composite indices of femoral neck strength (compression strength index [CSI], bending strength index, and impact strength index) in a group of young overweight men. To do so, we compared composite indices of femoral neck strength in active overweight men and insufficiently active overweight men. They were divided into 2 groups based on their physical activity level: 70 active overweight men (engaging in more than 150 minutes of physical activity per week; 8.7 ± 4.8 h/wk) and 26 insufficiently active overweight men (engaging in less than 150 minutes of physical activity per week; 1.2 ± 0.7 h/wk). Height (m) and weight (kg) were measured, and body mass index (kg/m²) was calculated. Bone mineral density was measured by dual-energy X-ray absorptiometry at whole body, lumbar spine, total hip, and femoral neck. Body weight, lean mass, fat mass, and body mass index were not significantly different between the 2 groups. CSI, bending strength index, and impact strength index were significantly higher in active overweight men compared to insufficiently active overweight men. After adjustment for age, physical activity (h/wk) and lean mass, only CSI remained higher in active overweight men compared to insufficiently active overweight men. This study suggests that, in young overweight men, being active (engaging in more than 150 minutes of physical activity per week) is associated with greater composite indices of femoral neck strength. To our knowledge, this is the first study that finds a significant difference regarding composite indices of femoral neck strength between 2 groups of young overweight men with different levels of physical activity.

Are the Relationships of Lean Mass and Fat Mass With Bone Microarchitecture Causal or Due to Familial Confounders? A Novel Study of Adult Female Twin Pairs

It is not known whether the relationships of lean mass (LM) and fat mass (FM) with bone microarchitecture and geometry are causal and/or are because of confounders, including familial confounders arising from genetic and environment effects shared by relatives. We tested the hypotheses that: (i) LM is associated with cortical bone traits, (ii) FM is associated with trabecular bone traits, and (iii) these relationships of LM and FM with bone microarchitecture and geometry have a causal component. Total body composition was quantified for 98 monozygotic (MZ) and 54 dizygotic (DZ) white female twin pairs aged 31 to 77 years. Microarchitecture at the distal tibia and distal radius was quantified using HRpQCT and StrAx software. We applied the Inference about Causation through Examination of FAmiliaL CONfounding (ICE FALCON) method. Within‐individuals, distal tibia total bone area, cortical area, cortical thickness, and trabecular number were positively associated with LM (standardized regression coefficient (β) = 0.13 to 0.43; all p < 0.05); porosity of the inner transitional zone (ITZ) was negatively associated with LM (β = −0.22; p < 0.01). Trabecular number was positively associated with FM (β = 0.40; p < 0.001), and trabecular thickness was negatively associated with FM (β = −0.27; p < 0.001). For porosity of ITZ and trabecular number, the cross‐pair cross‐trait association with LM was significant before and after adjustment for the within‐individual association with LM (all ps < 0.05). For trabecular number, the cross‐pair cross‐trait association with FM was significant before and after adjustment for the within‐individual association with FM (p < 0.01). There were no significant changes in these cross‐pair cross‐trait associations after adjustment for the within‐individual association (p = 0.06 to 0.99). Similar results were found for distal radius measures. We conclude that there was no evidence that the relationships of LM and FM with bone microarchitecture and geometry are causal; they must in part due to by familial confounders affecting both bone architecture and body composition. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Comparison of clinical risk factors for incident fracture in obese and non-obese community-dwelling older men

BACKGROUND

Obese older adults have higher bone mineral density (BMD), but other characteristics of obesity may predispose these individuals to fracture. We aimed to compare clinical risk factors for incident fracture in obese and non-obese older men.

METHODS

Body mass index (BMI) and body fat percentage were assessed at baseline by anthropometry and dual-energy X-ray absorptiometry, respectively, in 1625 community-dwelling men aged ≥70 years. Categories for non-obese and obese were <30 kg/m²and ≥30 kg/m² for BMI, and <30% and ≥30% for body fat percentage. Sociodemographic, medical, physical function and blood biochemistry parameters were collected at baseline. Self-reported incident fractures of any type and cause (excluding pathological fractures and fractures of hands, fingers, feet, toes and the skull) were confirmed by radiographic reports and recorded up to 9 years. Hip fractures were followed for 14 years using data linkage.

RESULTS

Prevalence of obesity was 27% according to BMI and 44% according to body fat percentage. There were no differences in incidence of any fracture between non-obese and obese men by BMI (10.7 vs 9.3%, respectively; P > 0.05) or body fat percentage (10.2 vs 10.6%, respectively; P > 0.05). Significant interactions were observed demonstrating that dementia increased hazard for incident any and hip fracture in non-obese men (adjusted hazard ratio 7.08; 95% CI 3.27-15.36 and 8.36; 3.13-22.31, respectively) but not obese men. Past-year falls increased hazard for any fracture in obese men (2.86; 95% CI 1.60-5.10) but not non-obese men while higher luteinizing hormone concentrations reduced hazard for hip fracture in obese men (0.91; 0.85-0.97 per IU/L) but not non-obese men.

CONCLUSIONS

In community-dwelling older men, obesity does not protect against incident fracture. Assessments of falls history and gonadotrophin levels, in addition to established clinical risk factors for fracture, may contribute to improvements in fracture prediction in obese older men.

Loss in DXA-estimated total body lean mass but not fat mass predicts incident major osteoporotic fracture and hip fracture independently from FRAX: a registry-based cohort study

During median follow-up 6.0 years in 9622 individuals, prior loss in estimated total body lean mass (TBLM), but not total body fat mass loss (TBFM), was associated with increased fracture risk, particularly for hip fracture.

INTRODUCTION

Weight loss, and especially muscle loss, adversely affects skeletal health. The FRAX® tool considers baseline body mass index, but not body composition nor changes in its components over time. Our aim was to compare the independent associations between prior loss in DXA-estimated TBLM and TBFM and subsequent fracture risk.

METHODS

We identified women and men age 40 years or older with two DXA assessments at least 1 year apart (median interval 3.3 years). TBLM and TBFM were estimated from weight, sex, and DXA of the spine and hip. Incident fractures and deaths were ascertained from linked population-based health service data after the date of the second DXA. Hazard ratios (HRs) from Cox regression models were used to study time to fracture from prior loss in TBLM and TBFM adjusted for FRAX-related covariates.

RESULTS

The study population consisted of 9622 individuals (mean age 67 [SD 10] years, 95% female). We identified 692 subjects with incident major osteoporotic fracture [MOF] and 194 with hip fracture. Mean TBLM loss was significantly greater in those with incident MOF and hip fracture (P < 0.001) while TBFM loss was only significantly greater in those with incident hip fracture (P < 0.001). Each SD greater TBLM loss was associated with 10-13% increased MOF risk and 29-38% increased hip fracture risk, adjusted for TBFM loss and other covariates. Prior TBFM loss was not associated with fractures when adjusted for TBLM loss.

CONCLUSIONS

Prior loss in total body lean mass, but not in fat mass, is associated with increased fracture risk, particularly hip fracture, independent of other risk factors. This is consistent with the hypothesis that muscle loss (sarcopenia) adversely impacts skeletal health and fracture risk.

Relationships between bone mineral density, body composition, and isokinetic strength in postmenopausal women

Objectives

The increase in body fat mass (BFM) and the loss of lean body mass (LBM) or muscle strength with age affects bone mineral (BMD). These factors increase the prevalence and incidence of obesity and sarcopenia, which have unclear effects on bone mineral density. The purpose of this study was to determine how the above selected factors affect BMD.

Methods

A cross-sectional study was conducted involving 58 women (aged 62.1 ± 4.8 years). Total body, left proximal femur, lumbar spine BMD, and body composition parameters were measured with dual-energy x-ray absorptiometry. Isokinetic flexion and extension strength of the dominant leg were measured at 60 deg./s. Grip strength was measured with the dominant upper extremity. To determine the volume of physical activity (PA), the PA level was monitored for seven consecutive days using an ActiGraph model GT1M accelerometer.

Results

BFM was positively associated with BMD of the proximal femur (β = 0.31; P < 0.05), whereas LBM or appendicular lean mass (ALM) did not relate to BMD at any sites. Dominant isokinetic strength also did not relate to BMD at any site. A/G (android/gynoid) fat ratio shows positive association with lumbar spine BMD after adjusting for YSM (years since menopause), height, smoking status, and steps per day.

Conclusion

We observed a positive association between proximal femur BMD and BFM, but not between LBM, ALM or isokinetic strength. A/G ratio and BMI showed a positive association with lumbar spine BMD or proximal femur BMD, respectively.

A decade of FRAX: how has it changed the management of osteoporosis?

The fracture risk assessment tool, FRAX^®, was released in 2008 and provides country-specific algorithms for estimating individualized 10-year probability of hip and major osteoporotic fracture (hip, clinical spine, distal forearm, and proximal humerus). Since its release, 71 models have been made available for 66 countries covering more than 80% of the world population. The website receives approximately 3 million visits annually. Following independent validation, FRAX has been incorporated into more than 80 guidelines worldwide. The application of FRAX in assessment guidelines has been heterogeneous with the adoption of several different approaches in setting intervention thresholds. Whereas most guidelines adopt a case-finding strategy, the case for FRAX-based community screening in the elderly is increasing. The relationship between FRAX and efficacy of intervention has been explored and is expected to influence treatment guidelines in the future.

Evaluation of common variants in the CNR2 gene and its interaction with abdominal obesity for osteoporosis susceptibility in Chinese post-menopausal females

Objectives

The objective of this study was to investigate the association of four single-nucleotide polymorphisms (SNPs) of the cannabinoid receptor 2 (CNR2) gene, gene-obesity interaction, and haplotype combination with osteoporosis (OP) susceptibility.

Methods

Chinese patients with OP were recruited between March 2011 and December 2015 from our hospital. In this study, a total of 1267 post-menopausal female patients (631 OP patients and 636 control patients) were selected. The mean age of all subjects was 69.2 years (sd 15.8). A generalized multifactor dimensionality reduction (GMDR) model and logistic regression model were used to examine the interaction between SNP and obesity on OP. For OP patient-control haplotype analyses, the SHEsis online haplotype analysis software (http://analysis.bio-x.cn/) was employed.

Results

The logistic regression model revealed that the C allele of rs2501431 and the G allele of rs3003336 were associated with increased OP risk, compared with those with wild genotype. However, no significant correlations were found when analyzing the association of rs4237 and rs2229579 with OP risk. The GMDR analysis suggested that the interaction model composed of two factors, rs3003336 and abdominal obesity (AO), was the best model with statistical significance (p-value from sign test (P_sign) = 0.012), indicating a potential gene-environment interaction between rs3003336 and AO. Overall, the two-locus models had a cross-validation consistency of 10/10 and had a testing accuracy of 0.641. Abdominally obese subjects with the AG or GG genotype have the highest OP risk, compared with subjects with the AA genotype and normal waist circumference (WC) (odds ratio (OR) 2.23, 95% confidence interval (CI) 1.54 to 3.51). Haplotype analysis also indicated that the haplotype containing the rs3003336-G and rs2501431-C alleles was associated with a statistically increased OP risk.

Conclusion

Our results suggested that the C allele of rs2501431 and the G allele of rs3003336 of the CNR2 gene, interaction between rs3003336 and AO, and the haplotype containing the rs3003336-G and rs2501431-C alleles were all associated with increased OP risk.

Cite this article: Bone Joint Res 2019;8:544–549.

Interactions between Sedentary and Physical Activity Patterns, Lean Mass, and Bone Density in Arab Men

The study examined the associations between physical activity and appendicular lean mass (ALM), fat mass, and bone mineral density (BMD) and examined the role of physical activity on these variables. The participants included 497 men (age: 32.2 ± 10.4 years and body mass index: 28.2 ± 5.4 kg/m²). The study was cross-sectional, and measurements included body composition measured on dual-energy X-ray absorptiometry and self-reported physical activity assessed using the International Physical Activity Questionnaire. Physical activity, including light physical activity, was associated with increased ALM (P ≤ 0.05). Fat indicators, including waist circumference, were positively associated with ALM (P ≤ 0.05), but not with BMD. Physical activity, including moderate-to-vigorous physical activity, was not associated with BMD, whereas ALM and handgrip strength were significantly associated with BMD (P ≤ 0.05). Physical activity independent of exercise intensity was directly associated with ALM and indirectly associated with BMD through increased muscle mass and strength.

Associations of Body Composition Trajectories with Bone Mineral Density, Muscle Function, Falls, and Fractures in Older Men: The Concord Health and Ageing in Men Project

Background

Weight loss increases fracture risk in older adults. We aimed to determine associations of 2-year body composition trajectories with subsequent falls and fractures in older men.

Methods

We measured appendicular lean mass (ALM) and total fat mass (FM) by dual-energy X-ray absorptiometry at baseline and Year 2 in 1,326 community-dwelling men aged ≥70 and older. Body composition trajectories were determined from residuals of a linear regression of change in ALM on change in FM (higher values indicate maintenance of ALM over FM), and a categorical variable for change in ALM and FM (did not lose [≥−5% change] versus lost [&lt;−5% change]). Bone mineral density (BMD), hand grip strength, and gait speed were assessed at Years 2 and 5. After Year 2, incident fractures (confirmed by radiographical reports) and falls were recorded for 6.8 years.

Results

Compared with men who did not lose ALM or FM, men who did not lose ALM but lost FM, and men who lost both ALM and FM, had reduced falls (−24% and −34%, respectively; both p &lt; .05). Men who lost ALM but did not lose FM had increased falls (incidence rate ratio = 1.73; 95% CI 1.37–2.18). ALM/FM change residuals were associated with improved lumbar spine BMD (B = 0.007; 95% CI 0.002–0.012 g/cm2 per SD increase) and gait speed (0.015; 0.001–0.029 m/s), and reduced hip fractures (hazard ratio = 0.68; 95% CI 0.47–0.99).

Conclusions

Fracture risk may be increased in older men who lose higher ALM relative to FM. Weight loss interventions for obese older men should target maintenance of lean mass.

The Prediction of Body Composition in African Americans From Spine and Hip Dual-Energy Absorptiometry

Body composition, the makeup of the body's fat and lean tissue, is associated with important health outcomes and provides useful clinical information. Although body composition can be measured with total body dual-energy X-ray absorptiometry (DXA), this is rarely performed. As an alternative to total body DXA measurement, methods for estimation of body composition have been developed. These methods use soft tissue measures from spine and hip DXA to predict body composition and include prediction equations previously published by Leslie and proprietary equations within General Electric densitometry software. However, these estimates have not been tested in African Americans (AA), an ethnicity with a different distribution of fat than Caucasians (CA). Therefore, we examined the performance of the existing models in 99 CA and 162 AA subjects over the age of 40 who had total body, spine, and hip DXA measurements. We observed that existing models estimated body composition well in CA but underestimated fat mass and overestimated lean mass in AA. AA subjects were then randomly divided into 2 equal-sized subgroups-the first to develop new prediction equations and the second to independently validate them. We found that body composition can be more accurately estimated using either a new model that we derived in AA subjects using backward stepwise elimination or by adding a fixed offset for AA to the previously published model. Our results demonstrate that body composition estimates from spine and hip DXA require consideration of race/ethnicity.

Association of body composition with predicted hip bone strength among Chinese postmenopausal women: a longitudinal study

Body composition and bone strength are closely associated. How lean mass (LM) and fat mass (FM) contribute to bone strength remains ambiguous. We investigated the associations of total body LM and FM with changes in predicted hip bone strength over a period of 3 years in 1,743 postmenopausal Chinese women from the communities of Guangzhou, China. The body compositions of the women were obtained with dual-energy X-ray absorptiometry. We used the hip structure analysis program to obtain the bone parameters at the femoral neck region, including the bone mineral density (BMD), cross-sectional area (CSA), cortical thickness (CT), section modulus (SM) and buckling ratio (BR). We found the FM and LM were positive predictors for hip bone strength (β > 0, P < 0.05). The LM had a larger contribution to the BMD, CSA, CT, SM and/or their annual percent changes (βLM > βFM), while the contribution of FM to the BR and its annual percent change was higher than LM (|βFM| > |βLM|). Further analysis found that the associations of FM and LM with bone parameters were stronger in the underweight and normal weight participants (|βBMI1| > |βBMI2|). Overall, FM and LM had positive but differential effects on predicted hip bone strength, with a higher impact in the thinner participants.

European guidance for the diagnosis and management of osteoporosis in postmenopausal women

Guidance is provided in a European setting on the assessment and treatment of postmenopausal women at risk from fractures due to osteoporosis.

INTRODUCTION

The International Osteoporosis Foundation and European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis published guidance for the diagnosis and management of osteoporosis in 2013. This manuscript updates these in a European setting.

METHODS

Systematic reviews were updated.

RESULTS

The following areas are reviewed: the role of bone mineral density measurement for the diagnosis of osteoporosis and assessment of fracture risk; general and pharmacological management of osteoporosis; monitoring of treatment; assessment of fracture risk; case-finding strategies; investigation of patients; health economics of treatment. The update includes new information on the evaluation of bone microstructure evaluation in facture risk assessment, the role of FRAX® and Fracture Liaison Services in secondary fracture prevention, long-term effects on fracture risk of dietary intakes, and increased fracture risk on stopping drug treatment.

CONCLUSIONS

A platform is provided on which specific guidelines can be developed for national use.

Estimating body mass and composition from proximal femur dimensions using dual energy x-ray absorptiometry

Body mass prediction from the skeleton most commonly employs femoral head diameter (FHD). However, theoretical predictions and empirical data suggest the relationship between mass and FHD is strongest in young adults, that bone dimensions reflect lean mass better than body or fat mass and that other femoral measurements may be superior. Here, we generate prediction equations for body mass and its components using femoral head, neck and proximal shaft diameters and body composition data derived from dual-energy x-ray absorptiometry (DXA) scans of young adults (n = 155, 77 females and 78 males, mean age 22.7 ± 1.3 years) from the Andhra Pradesh Children and Parents Study, Hyderabad, India. Sex-specific regression of log-transformed data on femoral measurements predicted lean mass with smaller standard errors of estimate (SEEs) than body mass (12-14% and 16-17% respectively), while none of the femoral measurements were significant predictors of fat mass. Subtrochanteric mediolateral shaft diameter gave lower SEEs for lean mass in both sexes and for body mass in males than FHD, while FHD was a better predictor of body mass in women. Our results provide further evidence that lean mass is more closely related to proximal femur dimensions than body or fat mass and that proximal shaft diameter is a better predictor than FHD of lean but not always body mass. The mechanisms underlying these relationships have implications for selecting the most appropriate measurement and reference sample for estimating body or lean mass, which also depend on the question under investigation.

Relationship between body mass, lean mass, fat mass, and limb bone cross-sectional geometry: Implications for estimating body mass and physique from the skeleton

OBJECTIVES

Estimating body mass from skeletal dimensions is widely practiced, but methods for estimating its components (lean and fat mass) are poorly developed. The ability to estimate these characteristics would offer new insights into the evolution of body composition and its variation relative to past and present health. This study investigates the potential of long bone cross-sectional properties as predictors of body, lean, and fat mass.

MATERIALS AND METHODS

Humerus, femur and tibia midshaft cross-sectional properties were measured by peripheral quantitative computed tomography in sample of young adult women (n = 105) characterized by a range of activity levels. Body composition was estimated from bioimpedance analysis.

RESULTS

Lean mass correlated most strongly with both upper and lower limb bone properties (r values up to 0.74), while fat mass showed weak correlations (r ≤ 0.29). Estimation equations generated from tibial midshaft properties indicated that lean mass could be estimated relatively reliably, with some improvement using logged data and including bone length in the models (minimum standard error of estimate = 8.9%). Body mass prediction was less reliable and fat mass only poorly predicted (standard errors of estimate ≥11.9% and >33%, respectively).

DISCUSSION

Lean mass can be predicted more reliably than body mass from limb bone cross-sectional properties. The results highlight the potential for studying evolutionary trends in lean mass from skeletal remains, and have implications for understanding the relationship between bone morphology and body mass or composition.

Dairy product consumption and risk of hip fracture: a systematic review and meta-analysis

BACKGROUND

Dairy product consumption may affect the risk of hip fracture, but previous studies have reported inconsistent findings. The primary aim of our meta-analysis was to examine and quantify the potential association of dairy product consumption with risk of hip fracture.

METHODS

We searched the databases of PubMed and EMBASE for relevant articles from their inception through April 17, 2017. The final analysis included 10 cohort studies and 8 case-control studies. Random-effects models were used to estimate the pooled risk. Subgroup and dose-response analyses were conducted to explore the relationships between the consumption of milk and the risk of hip fracture.

RESULTS

After pooling the data from the included studies, the summary relative risk (RR) for hip fracture for highest versus lowest consumption were 0.91 (95% CI: 0.74-1.12), 0.75 (95% CI: 0.66-0.86), 0.68 (95% CI: 0.61-0. 77), 1.02 (95% CI: 0.93-1.12) for milk, yogurt, cheese, and total dairy products in cohort studies, respectively. Higher milk consumption [Odds ratio (OR), 0.71, 95% CI: 0.55-0. 91] was associated with lower risk of hip fracture for highest versus lowest consumption in case-control studies. After quantifying the specific dose of milk, the summary RR/OR for an increased milk consumption of 200 g/day was 1.00 (95% CI: 0.94-1.07), and 0.89 (95%CI: 0.64-1.24) with significant heterogeneity for cohort and case-control studies, respectively; There was a nonlinear association between milk consumption and hip fracture risk in cohort, and case-control studies.

CONCLUSIONS

Our findings indicate that consumption of yogurt and cheese was associated with lower risk of hip fracture in cohort studies. However, the consumption of total dairy products and cream was not significantly associated with the risk of hip fracture. There was insufficient evidence to deduce the association between milk consumption and risk of hip fracture. A lower threshold of 200 g/day milk intake may have beneficial effects, whereas the effects of a higher threshold of milk intake are unclear.

Use of dual energy X-ray absorptiometry in pediatric patients

Dual Energy X-ray Absorptiometry (DXA) is a vital tool for assessing bone health in patients at risk for fragility fractures. In pediatric patients, this technology is used in conjunction with clinical fracture history to diagnosis osteoporosis and monitor treatment response. Childhood and adolescence is characterized by linear growth and bone mass accrual; thus there are important differences in the interpretation of bone measurements obtained by DXA in these young patients. This review aims to explore the current indications for DXA use and interpretation of DXA in the pediatric age group using currently available reference databases. Limitations of DXA in pediatric patients, specifically in children with short stature, will be explored. We will review several pathophysiologic mechanisms that may lead to low bone density in children, discussing representative diseases and the recommendations for monitoring bone health with DXA in these conditions. Finally, we will highlight new methods by which DXA imaging can gather additional information on bone health in children and may improve our ability to predict fractures and osteoporosis.

Appendicular and whole body lean mass outcomes are associated with finite element analysis-derived bone strength at the distal radius and tibia in adults aged 40years and older

PURPOSE

The purpose of this cross-sectional study was to determine how appendicular lean mass index (ALMI), and whole body lean (LMI) and fat mass indices (FMI) associate with estimated bone strength outcomes at the distal radius and tibia in adults aged 40 years and older.

METHODS

Dual energy X-ray absorptiometry (DXA) scans were performed to determine body composition, including whole body lean and fat mass, and appendicular lean mass. ALMI (appendicular lean mass/height²), LMI (lean tissue mass/height²) and FMI (fat mass/height²) were calculated. High-resolution peripheral quantitative computed tomography (HRpQCT) scans were performed to assess bone structural properties at the distal radius and tibia. Using finite element analysis, failure load (N), stiffness (N/mm), ultimate stress (MPa), and cortical-to-trabecular load ratio were estimated from HRpQCT scans. The associations between body composition (ALMI, LMI, FMI) and estimated bone strength were examined using bivariate and multivariable linear regression analyses adjusting for age, sex, and other confounding variables.

RESULTS

In 197 participants (127 women; mean±SD, age: 69.5±10.3y, body mass index: 27.95±4.95kg/m², ALMI: 7.31±1.31kg/m²), ALMI and LMI were significantly associated with failure load at the distal radius and tibia (explained 39%-48% of the variance) and remained significant after adjusting for confounding variables and multiple testing (R²=0.586-0.645, p<0.001). ALMI, LMI, and FMI did not have significant associations with ultimate stress in our multivariable models. FMI was significantly associated with cortical-to-trabecular load ratio at the distal radius and tibia (explained 6%-12% of the variance) and remained significant after adjusting for confounders and multiple testing (R²=0.208-0.243, p<0.001). FMI was no longer significantly associated with failure load after adjusting for confounders.

CONCLUSION

These findings suggest that ALMI and LMI are important determinants of estimated bone strength, particularly failure load, at the distal radius and tibia, and may contribute to preservation of bone strength in middle-to-late adulthood.