Relative contribution of body composition to bone mineral density at different sites in men and women of South Korea

We examined the relative contribution of body composition to bone mineral density (BMD) at various sites in 1406 Korean rural men and women, aged 19–80 years, from July to August 2004. The BMD was measured at peripheral (distal forearm and calcaneus) and central (lumbar spine at L1–L4, femoral neck, trochanter, and Ward's triangle) using dual-energy X-ray absorptiometry. In multivariate analyses, the linear regression models were adjusted for relevant covariates. In premenopausal women, only lean mass had a significant positive correlation with BMD at all sites. In postmenopausal women, fat mass was significantly positively correlated with BMD at all sites, except the Ward's triangle; fat mass was the only determinant of BMD at the lumbar, distal forearm, and calcaneus sites, whereas both lean and fat mass contributed to BMD at the hip, with the effect of lean mass being slightly greater than that of fat mass. In younger men, lean mass had a significant positive contribution to BMD at all sites, whereas fat mass appeared to contribute negatively to BMD at all sites, except the calcaneus. In older men, lean mass made a significant positive contribution to the BMD at all sites; fat mass also made a significant positive contribution to the BMD at the forearm and calcaneus. These data indicate that in the Korean rural population, lean mass may be an important determinant of the BMD, whereas fat mass may contribute positively to BMD only in postmenopausal women and older men.     

Analysis of factors affecting increase in bone mineral density at lumbar spine by bisphosphonate treatment in postmenopausal osteoporosis

Bisphosphonate is an effective drug to reduce fracture risk in osteoporotic patients; however, factors affecting the efficacy of bisphosphonate treatment are not fully known, especially in Japanese patients. In the present study, we examined the relationships between an increase in lumbar spine bone mineral density (BMD) by bisphosphonates and several pretreatment parameters, including biochemical, bone/mineral, and body composition indices, in 85 postmenopausal osteoporotic patients treated with alendronate or risedronate. BMD increase was measured by dual-energy X-ray absorptiometry at the lumbar spine before and 2 years after treatment. BMD increase at the lumbar spine was observed as independent of age, height, weight, body mass index, and fat mass, although lean body mass seemed slightly related. On the other hand, fasting plasma glucose (FPG) levels were significantly and positively related to BMD increase at the lumbar spine. In multiple regression analysis, FPG levels were not significantly related to BMD increase at the lumbar spine when lean body mass was considered. As for bone/mineral parameters, BMD increase at the lumbar spine was not significantly related to serum levels of calcium, parathyroid hormone (PTH), and alkaline phosphatase or urinary levels of deoxypiridinoline and calcium excretion. As for BMD parameters, Z-scores of BMD at any site and bone geometry parameters obtained by forearm peripheral quantitative computed tomography were not significantly related to BMD increase at the lumbar spine. BMD increases at the lumbar spine were similar between groups with or without vertebral fractures. In conclusion, BMD increase at the lumbar spine by bisphosphonate treatment was not related to any pretreatment parameters, including body size, body composition, and bone/mineral metabolism in postmenopausal Japanese women with primary osteoporosis, although FPG correlated partly to BMD through lean body mass.     

Bone mass and body composition in normal women.

The interrelationships between measurements of bone mass and total-body bone mineral were examined in a cross-sectional study of normal healthy women aged 17-82 years. In addition we evaluated the relationship between measures of body composition, estimated by four independent techniques, and bone mass in the same population. Considering the group as a whole, bone mass at all sites correlated with each other and with total-body bone mineral (TBBM). Cancellous and cortical sites could predict TBBM equally well. As expected, all measurements of bone mass were significantly lower in postmenopausal women in comparison to premenopausal women. Declines in bone mass were only seen in premenopausal women in the femoral neck and Ward's triangle, not in lumbar spine, radius, or skeleton as a whole. In postmenopausal women bone mass correlated negatively with age and years from menopause equally at all sites. TBBM was significantly related to height and weight in both premenopausal and postmenopausal women. In premenopausal and postmenopausal women TBBM also correlated with fat mass, but TBBM was much better correlated with percentage body fat in premenopausal than postmenopausal women. TBBM was a constant proportion of lean body mass in premenopausal women, but the fraction of lean mass occupied by the skeleton declined with age in postmenopausal women. Correction of TBBM for lean mass did not change the relationship between TBBM and percentage fat in premenopausal women but eliminated the relationship in postmenopausal women. Regional measurements, which are at least partially corrected for body size by dividing mass by area, correlated less well with height and weight and with any index of obesity, especially in postmenopausal women.     

Relation of forearm's bone and soft tissues to infant's body composition.

Small portable units using the dual X-ray absorptiometry method (pDEXA) are becoming available to evaluate a localized region of the body such as the forearm. The purpose of this study was to evaluate the relationship between infant's forearm measurements of bone mineral, lean, and fat mass and total body composition. Twenty-two infants participated in this study. Mean age of the infants was 21 d with a weight range of 1-3.6 kg. All infants were stable and had their forearm and total body scanned on the same day. The long-term precision error for the pDEXA was 0.4%. The infant's total body was scanned by the XR-26 (Norland Medical Systems, Fort Atkinson,WI). Forearm bone mineral content, bone mineral density (BMD), fat mass, and lean mass correlated to total body mineral content (BMC) (r = 0.84, p < 0.001), total body BMD (r = 0.73, p < 0.001), total fat mass (r = 0.53, p < 0.05), and total body lean mass (r = 0.80, p < 0.001). Forearm BMC, lean, and fat mass correlated significantly with body weight and length (r = 0.73-0.94). In conclusion, forearm measurements of bone mineral, fat, and lean mass reflect total body bone mineral, fat, and lean mass in small infants.     

Influence of body composition on quantitative ultrasound parameters of the os calcis in a population-based sample of pre- and postmenopausal women

Body mass is known to be related to measures of bone mineral density (BMD) as well as to parameters of quantitative ultrasound (US). To examine the effect of the body compartment's fat mass and lean body mass on quantitative ultrasonic bone parameters, data from a sample of 3241 German women were analyzed. Anthropometric measures, including skinfold thickness, were obtained from standardized measurements, and fat and lean body mass were derived from classical regression formulas based on skinfold measurements. Ultrasonic bone measurements were performed on the right os calcis, and speed of sound (SOS) and broadband ultrasound attenuation (BUA) were determined. Women were grouped into pre- and postmenopausal status; postmenopausal women were further stratified into ever and never hormone-replacement user. Correlation analysis indicated lean body mass to be stronger correlated with BUA than fat mass in both pre- (r = 0.23; P= 0.0001) and postmenopausal women with (r = 0.19; P= 0.0001) and without hormone replacement therapy (HRT) (r = 0.26; p = 0.0001). SOS demonstrated very small or no associations with body mass or its components. Multiple linear regression models were used to describe the relationship among body weight, fat mass, and lean body mass on BUA after adjustment for confounding variables. Both in pre- and postmenopausal women lean body mass was more strongly related to BUA than fat mass. However, body mass measures explained only small amounts of the overall variance in BUA (R²= 1–3% in premenopausal women; R²= 1% postmenopausal with HRT; R²= 4–5% in postmenopausal women without HRT). In conclusion, the strong influence of body mass and its components previously reported for BMD was not observed for quantitative ultrasonic bone parameters. Received: 5 January 1999 / Accepted: 1 July 1999     

Anthropometric predictors of geometric indices of hip bone strength in a group of Lebanese postmenopausal women

The effects of anthropometric characteristics on hip bone strength in postmenopausal women are not completely elucidated. The aim of this study was to investigate the influence of anthropometric characteristics on geometric indices of hip bone strength using the hip structure analysis (HSA) program in a group of Lebanese postmenopausal women. This study included 109 postmenopausal women (aged 64--84yr). Age and years since menopause were recorded. Body composition and bone mineral density were assessed by dual-energy X-ray absorptiometry (DXA). To evaluate hip bone strength, DXA scans were analyzed at the femoral neck (FN), the intertrochanteric (IT), and the femoral shaft (FS) by the HSA program. Cross-sectional area (CSA), an index of axial compression strength, section modulus (Z), an index of bending strength, and buckling ratio (BR), an estimate of cortical stability in buckling, were measured from bone mass profiles. Using univariate analysis, weight, height, body mass index (BMI), lean mass, and fat mass were positively correlated to CSA and Z of the FN, IT, and FS. Weight, BMI, fat mass, and fat mass percentage were negatively correlated to BR of the FN, IT, and FS. Multiple linear regression analysis showed that lean mass was a stronger determinant of FN CSA, FN Z, IT Z, and FS Z than fat mass, whereas fat mass was a stronger determinant of IT CSA, FS CSA, IT BR, and FS BR than lean mass. This study suggests that, in postmenopausal women, fat mass is a strong predictor of hip axial compression strength and cortical stability in buckling, and lean mass is a strong predictor of hip bending strength.     

Volumetric bone density of the lumbar spine is related to fat mass but not lean mass in normal postmenopausal women

We have previously found that fat mass but not lean body mass is related to bone mineral density (BMD) in women. In these and most other studies of the dependence of BMD on body composition, areal rather than volumetric bone density was measured. It is possible that the dependence of this variable on body size introduced a scale artifact that contributed to the previous findings. The present study addresses this issue by measuring thevolumetric density of the third lumbar vertebra from simultaneous anteroposterior (AP) and lateral scans using dual-energy X-ray absorptiometry in 119 normal postmenopausal women. Whole body fat and lean body mass were also measured using this technique. In the AP projection, BMD was similarly related to body weight and to fat mass (r=0.44,p<0.0001 for both) but not to lean body mass (r=0.17, NS). BMD in the lateral projection was less closely related to body composition than was AP BMD, but the greater impact of fat (r=0.25,p<0.01) than lean body mass (r=0.09, NS) was still evident. When AP or lateral BMDs were divided by height, arm span or the square root of the scan area to produce an index with the dimensions of volumetric density, the dependence of BMD on body weight and fat mass were not affected but the relationship to lean body mass was eliminated (–0.02<r<0.09). Similarly, the volumetric density of the third lumbar vertebra was related to fat mass (r=0.21,p=0.02) but not to lean body mass (r=0.01). It is concluded that BMD is related to fat mass and that previously reported associations between lean body mass and BMD are probably contributed to by a scaling factor arising from failure to measure volumetric bone density.     

Relationship of body composition, muscle strength, and aerobic capacity to bone mineral density in older men and women

We evaluated the relationship of body composition, maximal aerobic capacity (VO2max), and muscle strength to bone mineral density in 91 healthy men and women, age 61-84 years. Lean body mass was estimated from two independent measures of fat mass, bioelectrical impedance and skinfold thickness. VO2max was determined by treadmill ergometry with direct measurement of oxygen consumption. Grip and back strength were measured by isometric dynamometry. Mineral density of lumbar spine and midradius were measured by dual- and single-photon absorptiometry. Men had significantly greater lean mass, muscle strength, aerobic capacity, and bone density than women. In women, grip strength correlated with forearm and spine density (r = 0.37, r = 0.28, p less than 0.05). In men, grip strength correlated with forearm density (r = 0.47, p less than 0.05), and back strength was significantly correlated with both spine (r = 0.46, p less than 0.01) and forearm density (r = 0.46, p less than 0.01). In women, neither forearm nor spine density correlated significantly with aerobic capacity. In men, midradius density did not correlate significantly with oxygen consumption, but the simple correlation between spine density and VO2max was significant (r = 0.41, p less than 0.05). Back strength and VO2max were significantly related in men (r = 0.47, p less than 0.01). By stepwise multiple regression, back strength emerged as the most robust predictor of spine mineral, accounting for 19% of the variation in bone density. Addition of VO2max to the regression did not add significant predictive value. However, when VO2max was expressed per kilogram lean body mass, both back strength and VO2max contributed significantly to the prediction of spine density in men, and the coefficient of determination R2 increased to 0.30. We conclude that body mass and grip strength, but not aerobic capacity, significantly predict bone density in elderly women. In elderly men, back strength is a more robust predictor of axial bone density than traditional expressions of aerobic capacity, but VO2max per kilogram lean mass and back strength both make significant contributions to the prediction of spine mineral density. The applicability of these results to younger men and women is uncertain.     

Relative Importance of Lean Mass and Fat Mass on Bone Mineral Density in a Group of Lebanese Postmenopausal Women

The aim of this study was to determine the relative importance of lean mass and fat mass on bone mineral density (BMD) in a group of Lebanese postmenopausal women. One hundred ten Lebanese postmenopausal women (aged 65–84 yr) participated in this study. Age and years since menopause were recorded. Body weight and height were measured and body mass index (BMI) was calculated. Body composition (lean mass, fat mass, and fat mass percentage) was assessed by dual-energy X-ray absorptiometry (DXA). Bone mineral content (BMC) of the whole body (WB) and BMD of the WB, the lumbar spine (L1–L4), the total hip (TH), the femoral neck (FN), the ultra distal (UD) Radius, and the 1/3 Radius were measured by DXA. The expressions WB BMC/height and WB BMD/height were also used. Weight, BMI, fat mass, and lean mass were positively correlated to WB BMC, WB BMC/height, WB BMD/height, and to WB, L1–L4, TH, FN, UD Radius, and 1/3 Radius BMD. However, using multiple linear regression analyses, fat mass was more strongly correlated to BMC and to BMD values than lean mass after controlling for years since menopause. This study suggests that fat mass is a stronger determinant of BMC and BMD than lean mass in Lebanese postmenopausal women.     

Body composition and bone density in Canadian White and Aboriginal women: the First Nations Bone Health Study

Ethnic variation in soft tissue composition may contribute to observed ethnic differences in bone mineral density (BMD). This analysis was performed to determine whether ethnic differences in body composition affect differences in BMD between Canadian White and Aboriginal women. An age-stratified population-based sample of 206 Aboriginal women and 177 White women underwent multisite bone density measurements and total body soft tissue composition analysis. In univariate analyses, each kg of additional lean mass was associated with a greater increase in BMD than an equal amount of fat mass (p < .01). When models simultaneously evaluated both soft tissue measurements, lean mass (but not fat mass) was positively correlated with BMD at all measurement sites (p < .001). Aboriginal women had significantly lower weight-adjusted BMD than White women for two sites (calcaneus, p = .019; total body, p = .026) and lower BMI-adjusted for BMD three sites (calcaneus, p = .0076; distal forearm, p = .047; total body, p = .022). The ratio of lean mass to fat mass was lower in Aboriginal than White women (p < .001). When BMD was adjusted for body composition variables no significant difference was seen between Aboriginal and White women. Apparent ethnic differences in weight- and BMI-adjusted BMD between Canadian White and Aboriginal women were explained by a lower ratio of lean mass to fat mass in Aboriginal women, combined with a smaller increment in BMD from fat mass versus lean mass in both populations.     

Fat mass is negatively associated with bone mineral content in Koreans

Summary

Although obesity and osteoporosis are important public health problems, the effect of fat mass on bone mass remains controversial. This study demonstrated that fat mass was inversely related to bone mineral content, and abdominal obesity was significantly associated with bone mineral content independent of total fat mass.

Introduction

Obesity and osteoporosis, two disorders of body composition, have become increasingly important public health problems throughout the world. However, the effect of fat mass on bone mass remains controversial. This study investigates the effect of fat mass and regional fat distribution on bone mass within a community-dwelling cohort.

Methods

A total of 3,042 subjects (1,284 men, 362 premenopausal women, and 1,396 postmenopausal women) were studied. Fat mass, percent fat mass, lean mass, percent lean mass, and bone mineral content (BMC) were measured by dual energy X-ray absorptiometry.

Results

Fat mass and percent fat mass decreased significantly across increasing tertiles of BMC in all three subgroups (men, premenopausal and postmenopausal women). In contrast, lean mass and percent lean mass increased significantly across tertiles of BMC in men, and a similar trend was also identified in postmenopausal women. Interestingly, although correlation analysis showed a positive association between fat mass and BMC (p?p?p?Conclusion This study demonstrated that fat mass was inversely related to BMC after removing the mechanical loading effect in Korean men and women. Moreover, abdominal obesity as measured by WC was significantly associated with BMC independent of total fat mass.     

Relationship of Body Fat and Its Distribution With Bone Mineral Density in Indian Population

Obesity has been associated with increased bone mineral density (BMD). There is evidence of differential effect of regional fat on BMD. Hence, we undertook this study to evaluate the correlation between total body fat and its distribution with BMD in nonobese (mean body mass index: 25.0 ± 4.7 kg/m²) Indian adult volunteers. A total of 2347 participants (men: 39.4% and women: 60.6%) included in this cross-sectional study were divided according to sex and age. Fasting blood samples were drawn for biochemical parameters. Percent total body, truncal, and leg fat and BMD at lumbar spine, femur, and forearm were measured by dual-energy X-ray absorptiometry. The BMD at all sites (radius, femur, and spine) increased from lowest to highest quartiles of percent body fat. Percent truncal fat was positively correlated with BMD at all sites in both sexes, except for femoral neck in men, where it had negative correlation. Percent leg fat was positively related with BMD at all sites in premenopausal women, and spine and radius BMD in postmenopausal women. However, in men, it had negative correlation with femoral neck BMD. On multiple regression analysis, regional fat had positive association with BMD at all sites after adjusting for age, sex, lean mass index, 25-hydroxyvitamin D, and intact parathyroid hormone levels. Leg-to-total body fat ratio was negatively associated with BMD at all sites in men and pre- and postmenopausal women. Percent total body and regional fat have positive association with BMD at all sites in men and women.     

Glucocorticoid excess during adolescence leads to a major persistent deficit in bone mass and an increase in central body fat.

Endogenous Cushing's syndrome (CS) in children causes growth retardation, decreased bone mass, and increased total body fat. No prospective controlled studies have been performed in children to determine the long-term sequelae of CS on peak bone mass and body composition. A 15-year-old girl with Cushing disease (CD), and her healthy identical co-twin, were followed for 6 years after the CD was cured. At the 6-year follow-up both twins had areal bone mineral density (BMD) and body composition determined by dual-energy X-ray absorptiometry (DXA) and three-dimensional quantitative computed tomography (3DQCT). Z scores for height, weight, and body mass index (BMI) were -2.3, -0.8 and 0.2, and 1.2, 0.2, and -0.6, in the twin with CD and her co-twin, respectively. In the twin with CD, areal BMD and bone mineral apparent density (BMAD) at different sites varied from 0.7 to 3 SD below her co-twin. Volumetric lumbar spine bone density Z score was -0.75 and 1.0, and total body, abdominal visceral, and subcutaneous fat (%) was 42, 10, and 41 versus 26, 4, and 17 in the twin with CD and her co-twin, respectively. The relationship between total body fat and L2-L4 BMAD was inverse in the twin with CD (p < 0.05), which by contrast in her co-twin was opposite and direct (p < 0.001). In the twin with CD, despite cure, there was a persistent deficit in bone mass and increase in total and visceral body fat. These observations suggest that hypercortisolism (exogenous or endogenous) during adolescence may have persistent adverse effects on bone and fat mass.     

Body composition and vertebral fracture risk in female patients treated with glucocorticoid

Introduction Glucocorticoid (GC) causes bone loss and an increase in bone fragility. However, fracture risk was found to be only partly explained by bone mineral density in GC-treated patients (GC patients). Although GC causes a change in the distribution of fat in the body, the relationship between body composition and fracture risk in GC patients remains unknown. Methods The present study examined the relationship between the presence or absence of vertebral fractures and various indices, including body composition, in 92 premenopausal GC patients, 122 postmenopausal GC patients and 122 postmenopausal age-matched control subjects. Dual-energy X-ray absorptiometry was employed to analyze body composition. Results Percentage lean body mass (LBM), % fat and % trunk fat were not significantly different between postmenopausal GC patients and the control women. When groups with and without vertebral fractures were compared, % LBM and % fat were significantly higher and lower in groups with vertebral fractures, respectively, in postmenopausal GC patients, but not in the postmenopausal control women, although % trunk fat was not significantly different between groups with and without vertebral fractures. Femoral neck BMD was negatively correlated with % LBM and positively correlated with % fat. In premenopausal GC patients, % trunk fat was significantly higher in the fracture group, although % LBM and % fat were not significantly different between groups with and without vertebral fractures. Conclusion The present study revealed that body composition is related to vertebral fracture risk in GC-treated patients. Lower % fat can be included in the determination of vertebral fractures in postmenopausal GC-treated patients. The influence of body composition on vertebral fracture risk may be different between the pre- and postmenopausal state in GC patients.     

Contributions of lean mass and fat mass to bone mineral density: a study in postmenopausal women

Background  

The relative contribution of lean and fat to the determination of bone mineral density (BMD) in postmenopausal women is a contentious issue. The present study was undertaken to test the hypothesis that lean mass is a better determinant of BMD than fat mass.     

重庆地区围绝经期与绝经后妇女骨密度及身体成分相关指标分析

目的 调查重庆地区围绝经期与绝经后妇女(5~10年）骨密度及相关身体成分指标,分析身体成分指标与骨密度的关系,为本地区骨质疏松的防治提供线索。方法 ①选取2017年于本院进行健康体检年龄≥45岁的妇女956名(排除相关原发疾病）,其中围绝经期510名,绝经后446名,并分别记录身高、体重,计算出体质量指数(body mass index, BMI）;②使用美国GE公司双能X线骨密度仪测定受试者腰椎1~4、左侧股骨颈、大转子、股骨干、全髋的骨密度以及全身脂肪、肌肉含量与骨矿含量。结果 一般情况分析发现,重庆地区围绝经期妇女身高明显高于绝经后妇女［分别为(156.81 ± 5.27) cm、(153.32 ±5.51) cm］,而体质量指数无明显差异。 绝经后妇女肌肉含量(37.91 ± 6.42) kg、脂肪含量(17.84 ± 2.16) kg、骨矿含量(1.58±0.41) kg均较围绝经期妇女 [(37.88 ± 6.15) kg、(19.21 ± 2.07) kg、(1.75±0.20) kg ]降低。绝经后妇女诊断骨质疏松与低骨量的比例分别为28.92%、41.03%,高于围绝经期妇女低骨量的发生率(28.63%)。围绝经期妇女腰椎1~4和左侧股骨颈、大转子、股骨干及全髋骨密度 (bone mineral density, BMD)明显高于绝经后妇女［分别是(1.0 959 ± 0.1 603) g/m2和(0.8 410 ± 0.1 606) g/m2,(0.8 178 ± 0.1 577) g/m2和(0.7 872 ± 0.1 585) g/m2,(0.6 946 ± 0.1 252) g/m2和(0.6 728±0.1 274) g/m2,(1.0 329 ± 0.1 712) g/m2和(1.0 030±0.1 737) g/m2,(0.8 773 ± 0.1 448) g/m2和(0.8 495 ± 0.1 478) g/m2］。结论 绝经后妇女髋部、腰椎等部位BMD均较围绝经期妇女明显降低;骨质疏松及低骨量的发生率随年龄增加显著升高;和围绝经期妇女相比,绝经后妇女全身脂肪含量偏低;BMD与全身肌肉含量呈正相关性。     

Potential risk factors for development of postmenopausal osteoporosis — Examined over a 12-year period

In a longitudinal study, we investigated the influence of risk factors on bone mass at menopause and postmenopausal bone loss in 121 healthy postmenopausal women. These women had completed a 2-year prospective study in 1979 and a follow-up examination in 1989. Measurements of the bone mineral content in the distal forearm (single photon absorptiometry) were performed 9 times during the initial study and once at the follow-up examination. Bone mass at menopause (initial measurement), rate of early postmenopausal bone loss, and the subsequent rate of bone loss over 10 years were thus determined. In addition, the bone mineral density of the lumbar spine and proximal femur was measured by dual-energy X-ray absorptiometry (DXA) in 1989. Information about risk factors was assessed by standardized questionnaires and included reproductive history and lifestyle factors (intake of calcium and vitamin D supplements, consumption of alcohol and caffeine, smoking habits, and physical activity). Lactation, oral contraceptive use, and dietary calcium intake above 1500 mg per day was associated with significantly increased bone mass at menopause. The number of pregnancies reduced the rate of early postmenopausal bone loss, whereas moderate alcohol consumption reduced the subsequent rate of bone loss. Smoking significantly reduced femoral bone mineral density. In conclusion, the present prospective study showed that some of the examined putative risk factors positively influenced bone mass at menopause, especially calcium intake, whereas the postmenopausal bone loss was virtually unaffected. Assessment of risk factors in postmenopausal women thus seems to have limited value for reducing future risk of osteoporosis.     

Lifelong risk factors for osteoporosis and fractures in elderly women with low body mass index--a population-based study

Low body weight is associated with an increased risk for osteoporosis and fractures, but the contribution of other lifestyle related factors have not been previously studied within lean elderly women. The present study evaluated the association between lifelong lifestyle factors and bone density, falls and postmenopausal fractures in elderly women with low body mass index (BMI). A population-based sample of 1,222 women aged 70 to 73 years was stratified by BMI tertiles, and all 407 women in the lowest tertile participated. Data on falls and postmenopausal fractures, physical activity, functional capacity, calcium intake, smoking, alcohol intake and medical factors at different ages were obtained by a questionnaire. Calcaneum bone mass as broadband ultrasound attenuation (BUA) was assessed with a quantitative ultrasound (QUS) device, and bone mineral density (BMD) at the distal radius was measured with a dual-energy X-ray absorptiometry (DXA). Low current physical activity was associated with lower calcaneum BUA and factors associated with higher BUA were body weight, low lifetime occupational physical activity, hormone replacement and type 2 diabetes. Weight, type 2 diabetes and thiatzide use were associated with higher radius BMD. The final multivariate model consisted of four independent factors associated with fractures: low lifetime habitual physical activity (OR 3.7, 95% CI 1.9-7.1), diabetes (OR 0.2, 95% CI 0.1-1.0), living alone (OR 1.7, 95% CI 1.0-3.0) and calcaneum BUA (1.8, 95% CI 1.3-2.4). Poor functional ability and symptoms of depression were associated with recent falling. In elderly women with low BMI, lifelong physical activity may protect from fractures, while low calcaneum bone mass and living unpartnered appear to be associated with an increased risk for fractures. Poor functional ability and presence of depression may be associated with risk of falling. Type 2 diabetes may modify the risk of low bone mass and low-trauma postmenopausal fractures. Albeit that the results of this study need to be confirmed in prospective follow-up studies, multifactorial program with the emphasis on physical and social activation in the primary care setting for preventing falls and fractures in lean elderly women is recommended.     

Effects of tobacco use on axial and appendicular bone mineral density

Tobacco use has been identified as being a risk factor for the development of osteoporosis. While some data have suggested an effect on peripheral bone mass there are little previous data examining the role of tobacco use in axial skeletal bone loss. We examined tobacco use in relation to lumbar spine and proximal femur bone mineral density and forearm bone mineral content in 203 women. Data from identical twin pairs, comprising a subgroup of the larger group as well as a small number of male twin pairs, was also analyzed. The data show a difference in lumbar and proximal femur BMD of 0.03 and 0.06 g/cm2 respectively between smoking and nonsmoking identical twins. There was however no difference in the cross-sectional studies and no significant deleterious effect detected of tobacco use on forearm bone mineral content. The effect of smoking on lumbar and proximal femur bone mineral density, in identical twins discordant for tobacco use, was equivalent on average to 3 to 4 years of normal postmenopausal bone loss.     

Leptin, Fat Mass, and Bone Mineral Density in Healthy Pre- and Postmenopausal Women

The purpose was to examine relationships between age, fat mass, and bone mineral density (BMD) with resting leptin levels in premenopausal and postmenopausal women. Young (aged 18–30 yr, n = 30) and estrogen-deficient postmenopausal (aged 55–75 yr, n = 43) women were recruited. Total body and segmental fat mass and bone-free lean body mass (BFLBM) and total body, lumbar spine, and proximal femur BMD were assessed using dual-energy X-ray absorptiometry. Serum-resting, fasted leptin levels were measured by Immunoradiometric Assay (IRMA), and leptin-to-fat mass ratios were calculated. Young and older women had similar amounts of BFLBM, but older women had greater (p < 0.05) amounts of fat mass and 35% higher leptin levels. Age differences in leptin concentrations were no longer significant after controlling for fat mass. Older women had significantly (p < 0.05) lower hip BMD values. Age was negatively related (r = −0.29, p < 0.05) to leptin:trunk fat ratio. Increases in fat mass, not menopause per se, contributes to higher leptin levels in older women. Relationships between leptin and BMD may be age dependent.