Relative importance of lean mass and fat mass on bone mineral density in a group of Lebanese postmenopausal women

Determinants of bone mass in older adults with normal- and overweight derived from the crosstalk with muscle and adipose tissue

Lower bone mass in older adults may be mediated by the endocrine crosstalk between muscle, adipose tissue and bone. In 150 community-dwelling adults (59-86 years, BMI 17-37 kg/m²; 58.7% female), skeletal muscle mass index, adipose tissue and fat mass index (FMI) were determined. Levels of myokines, adipokines, osteokines, inflammation markers and insulin were measured as potential determinants of bone mineral content (BMC) and density (BMD). FMI was negatively associated with BMC and BMD after adjustment for mechanical loading effects of body weight (r-values between -0.37 and -0.71, all p < 0.05). Higher FMI was associated with higher leptin levels in both sexes, with higher hsCRP in women and with lower adiponectin levels in men. In addition to weight and FMI, sclerostin, osteocalcin, leptin × sex and adiponectin were independent predictors of BMC in a stepwise multiple regression analysis. Muscle mass, but not myokines, showed positive correlations with bone parameters that were weakened after adjusting for body weight (r-values between 0.27 and 0.58, all p < 0.01). Whereas the anabolic effect of muscle mass on bone in older adults may be partly explained by mechanical loading, the adverse effect of obesity on bone is possibly mediated by low-grade inflammation, higher leptin and lower adiponectin levels.

Spine trabecular bone scores and bone mineral density of postmenopausal Taiwanese women

OBJECTIVES

The aims of the study were to determine the mean trabecular bone score (TBS) of postmenopausal Taiwanese women and to analyze the value of TBS in predicting osteoporosis.

METHODS

A total of 1,915 postmenopausal women with lumbar spine and hip bone mineral density (BMD) and spine TBS were enrolled from a single medical center into this study. The women's BMD and TBS were measured using dual x-ray absorptiometry (Discovery Wi; Hologic, Bedford, Mass) and iNsight software (Med-Imaps SASU, Merignac, France), respectively. The women's demographic characteristics; lumbar spine, total hip, and femoral neck BMD; and lumbar spine TBS were recorded, and correlations among the parameters were identified using a 2-tailed Pearson test, in which a P value less than 0.05 was considered statistically significant. We developed simple linear regression models to represent changes related to TBS and performed an analysis of variance on the selected variables.

RESULTS

The average age of the women was 62.5 ± 9.1 years (range, 25.7-93.7 years). The mean TBS was 1.300 ± 0.086 (range, 1.015-1.596). The TBS was weakly and negatively correlated with body mass index ( r = -0.078) and moderately and positively correlated with the lumbar spine BMD ( r = 0.619). The patients' lowest BMD values among those measured at multiple sites revealed a higher rate of osteoporosis (32.5%) than those measured at individual sites. Degraded TBS were noted in 21.2% of the participants, and a combination of BMD and TBS results predicted more individuals (7.8%) at a high risk of fracture than did the BMD result only. The rates of both osteoporosis and degraded TBS increased with age.

CONCLUSIONS

Bone mineral density and TBS can be used in combination to predict osteoporosis in a greater number of postmenopausal Taiwanese women. Because the incidence of osteoporosis is the highest among older women, clinicians should pay careful attention to TBS degradation among older patients without low BMD.

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.

Influence of the appendicular skeletal muscle mass index on the bone mineral density of postmenopausal women

BACKGROUND

The appendicular skeletal muscle mass index (ASMI) is an important risk indicator for osteoporosis because of the anatomical proximity and metabolic connection between muscle and bone mass. The present study investigated the relationship between ASMI and the bone mineral density (BMD) categories of postmenopausal women.

METHODS

In this cross-sectional study with a probabilistic sample, sociodemographic, lifestyle, menopause time, anthropometric, and physical activity variables were collected. ASMI and BMD were assessed by dual-energy X-ray absorptiometry (DXA). Participants were grouped according to BMD values into normal density, osteopenia, and osteoporosis. Multivariate logistic regression models were applied to verify the influence of ASMI on BMD. Data were analyzed using the SPSS statistical software, version 22. The significance level for all tests was set at 5%.

RESULTS

Of the 114 women analyzed, most were between 60 and 69.9 years of age (62.3%), on menopause for ≤19.0 (51.8%), self-declared brown race/color (49.1%), had < 4 years of education (41.2%), never smoked (69.0%) or drank alcohol (62.8%). Of these, 52.6% were classified as sufficiently active and 52.2% had regular sun exposure. Women with osteoporosis were older (p = 0.035), on menopause for a longer time (p = 0.011), underweight (p = 0.004), had adequate waist circumference (p = 0.017), and low ASMI values (p = 0.002). There was an association between the 1st tertile of ASMI and osteoporosis. However, after adjustments for age, race/color, and body mass index, the strength of association between BMD and ASMI was not maintained.

CONCLUSIONS

ASMI was not associated with the BMD of the postmenopausal women evaluated. Total body and muscle mass, in addition to bone mass, should be monitored during menopause treatment. Longitudinal studies must be conducted to elucidate the mechanisms and gaps in this relationship.

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.

Composite Indices of Femoral Neck Strength in Middle-Aged Inactive Subjects Vs Former Football Players

The purpose of this study was to compare composite indices of femoral neck strength ((compression strength index [CSI], bending strength index [BSI], and impact strength index [ISI]) in inactive middle-aged men (n = 20) and middle-aged former football players (n = 15). 35 middle-aged men participated in this study. Body composition and bone variables were evaluated by dual-energy X-ray absorptiometry. Composite indices of femoral neck strength (CSI, BSI, and ISI) were calculated. Handgrip strength, vertical jump, maximum power of the lower limbs (watts), horizontal jump, maximal half-squat strength, maximal bench-press strength, sprint performance (10 meters), and maximum oxygen consumption (VO₂ max, ml/min/kg) were evaluated using validated tests. CSI, BSI, and ISI were significantly higher in football players compared to inactive men. Vertical jump, horizontal jump, maximal half-squat strength, VO₂ max and sprint performance were significantly different between the 2 groups. CSI, BSI, and ISI remained significantly higher in football players compared to inactive men after adjusting for physical activity level. The current study suggests that former football practice is associated with higher composite indices of femoral neck strength in middle-aged men.

Contributions of fat mass and fat distribution to hip bone strength in healthy postmenopausal Chinese women

The fat and bone connection is complicated, and the effect of adipose tissue on hip bone strength remains unclear. The aim of this study was to clarify the relative contribution of body fat accumulation and fat distribution to the determination of proximal femur strength in healthy postmenopausal Chinese women. This cross-sectional study enrolled 528 healthy postmenopausal women without medication history or known diseases. Total lean mass (LM), appendicular LM (ALM), percentage of lean mass (PLM), total fat mass (FM), appendicular FM (AFM), percentage of body fat (PBF), android and gynoid fat amount, android-to-gynoid fat ratio (AOI), bone mineral density (BMD), and proximal femur geometry were measured by dual energy X-ray absorptiometry. Hip structure analysis was used to compute some variables as geometric strength-related parameters by analyzing the images of the hip generated from DXA scans. Correlation analyses among anthropometrics, variables of body composition and bone mass, and geometric indices of hip bone strength were performed with stepwise linear regression analyses as well as Pearson's correlation analysis. In univariate analysis, there were significantly inverse correlations between age, years since menopause (YSM), hip BMD, and hip geometric parameters. Bone data were positively related to height, body weight, LM, ALM, FM, AFM, and PBF but negatively related to AOI and amount of android fat (all P < 0.05). AFM and AOI were significantly related to most anthropometric parameters. AFM was positively associated with height, body weight, and BMI. AFM was negatively associated with age and YSM. AOI was negatively associated with height, body weight, and BMI. AOI positively associated with age and YSM. LM, ALM, and FM had a positive relationship with anthropometric parameters (P < 0.05 for all). PLM had a negative relationship with those parameters. The correlation between LM, ALM, FM, PLM, ALM, age, and YSM was not significant. In multivariate linear regression analysis, the hip bone strength was observed to have a consistent and unchanged positive association with AFM and a negative association with AOI, whereas its association with other variables of body composition was not significant after adjusting for age, years since menopause, height, body weight, and BMI. AFM may be a positively protective effect for hip bone strength while AOI, rather than android fat, shows a strong negative association with hip bone strength after making an adjustment for confounders (age, YSM, height, body weight, and BMI) in healthy postmenopausal Chinese women. Rational weight control and AOI reduction during menopause may have vital clinical significance in decreasing postmenopausal osteoporosis.

Body mass index at 11 years and bone mass at age 18: path analysis within the 1993 Pelotas (Brazil) birth cohort study

Background

We investigated whether Body Mass Index (BMI) at 11 years old has a direct effect on bone mass at age 18 operating through alterations to bone growth and development, or whether the association is mediated by concurrent BMI, fat mass (FM), and fat free mass (FFM).

Methods

Path analysis was used to explore the association between BMI at age 11 and whole-body bone mineral content (BMC) and bone mineral density (BMD) assessed by dual-energy x-ray absorptiometry (DXA) at age 18 in a prospective birth cohort study comprising 3,307 adolescents; we also evaluated the degree to which this association was mediated by BMI, FM (kg) and FFM (kg) assessed by plethysmography (BOD POD) at age 18.

Results

We found a positive association between BMI at age 11 and BMC (males [β = 179.7 g, 95% CI 161.4; 198.0]; females [β = 179.9 g, 95% CI 165.3; 194.6]) and BMD (males [β = 0.030 g/cm2, 95% CI 0.024; 0.035]; females [β = 0.029 g/cm2, 95% CI 0.025; 0.033]) at age 18. This association was largely mediated by BMI and FFM at age 18 in both female and male adolescents. FM at age 18 was not an important mediator.

Conclusions

Concurrent BMI and FFM were the main mediators of the association between BMC/BMD in late adolescence and BMI in early adolescence.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-015-0529-y) contains supplementary material, which is available to authorized users.

Lean mass is the strongest predictor of bone mineral content in type-2 diabetes and normal individuals: an eastern India perspective

Background

Impact of body fat distribution on bone mineral content (BMC) and density (BMD) at different sites has not been studied in type-2 diabetes (T2DM). This study aimed to compare BMC and BMD in normal (BMI < 25 kg/m²) and increased BMI (BMI ≥ 25 kg/m²) T2DM patients with age and BMI matched normal controls, and evaluate the impact of lean mass and body fat distribution parameters on them.

Methods

Seventy-six T2DM patients and 56 normal controls underwent anthropometric assessment, blood sampling and estimation of BMC, BMD, body fat and lean mass distribution by dual energy X-ray absorptiometry (DXA).

Results

Increased BMI individuals (n = 63) had significantly higher BMD, BMC, fat mass and significantly lower 25-hydroxy-vitamin-D (25OHD), as compared to normal BMI individuals (n = 69). Lean mass had stronger positive correlation with BMC and BMD, compared to fat mass. BMI, sagittal abdominal diameter (SAD) and Android/Gynoid (A/G) ratio had positive correlation with BMC and BMD. Percent body fat had negative correlation with BMC and BMD. T2DM patients had higher central obesity (A/G ratio). WC was the best predictor of A/G ratio. Regression analysis revealed lean mass to be the strongest predictor of BMC after adjusting for age, sex, BMI and 25OHD, in normal individuals and patients with diabetes, followed by fat mass. BMD right femur, BMC, lean mass and A/G ratios were significantly higher in males (n = 74). Fat mass and percent body fat were significantly higher in females (n = 58). Fat mass was the best predictor of BMC in males where as lean mass was the best predictor of BMC in females.

Conclusion

Increased BMI and T2DM are associated with increased BMC and BMD at different sites, with lean mass having the strongest impact on BMC in normal individuals and patients with diabetes. Males have higher BMC and BMD as compared to females, likely due to a greater lean mass, A/G ratio, along with lesser fat mass and percent body fat.

The influence of weight status on radial bone mineral density in Lebanese women

The aim of this study was to investigate the influence of the weight-status (obese, overweight and normal-weight) on bone mineral density of the forearm in Lebanese women. 3,989 Lebanese women (1,138 obese, 1,570 overweight and 1,281 normal weight) aged from 19 to 92 years old participated in this study. Weight and height were measured, and body mass index (BMI) was calculated. BMD of the ultra-distal (UD) radius, the 1/3 radius and the total radius was measured by DXA (GE Healthcare Lunar Prodigy). In the whole population, body weight was positively correlated to UD Radius BMD (r = 0.41; P < 0.001), 1/3 radius BMD (r = 0.35; P < 0.001) and total radius BMD (r = 0.48; P < 0.001) while age was negatively correlated to UD BMD (r = -0.42; P < 0.001), 1/3 Radius BMD (r = -0.52; P < 0.001) and total radius BMD (r = -0.42; P < 0.001). Using multiple linear regression analysis models, age and weight explained 36 %, 41 % and 42 of the UD radius BMD, 1/3 radius BMD and total radius BMD variances respectively. UD radius BMD, 1/3 radius BMD and total radius BMD values were significantly different among the three groups (P < 0.001). UD Radius BMD, 1/3 radius BMD and total radius BMD values were higher in obese and overweight women compared to normal-weight women (P < 0.001) and in obese women compared to overweight women (P < 0.001). These differences among the three groups remained significant after adjusting for age and height (P < 0.001). This study suggests that obesity is associated with higher UD radius, 1/3 radius and total radius BMD values in Lebanese women. Thus, obesity seems to be protective against forearm osteopenia in Lebanese women.

Body fat, lean mass and bone density of the spine and forearm in women

The aim of this study was to determine the relative contributions of fat mass and lean mass to the variability of bone mineral density (BMD) of the lumbar spine and proximal 1/3 forearm in Bulgarian women. 180 women aged 21 through 76 years participated (mean age 50.8 ± 9.7 years). 130 of them were postmenopausal. Lumbar spine and forearm BMD were measured by dual-energy X-ray absorptiometry, followed by a whole-body scan for body composition examination (Hologic QDR 4500 A device, software version 1.26). The strongest linear correlation was found with body weight (r2=0.231, p<0.001). Using this model, 18.1 % of the variability of lumbar spine BMD was attributable to fat mass and 16.0 % to lean mass. The relative influence of fat mass on L1-L4 BMD was greater than that of lean mass (standardized regression coefficient 0.291 versus 0.199). There were weak correlations of body weight, fat and lean mass with the forearm BMD. Lean mass correlated slightly better (r=0.187, p=0.050) to forearm BMD than fat mass (r=0.162, p=0.055). In conclusion, the differentiation between fat and lean mass does not strengthen the BMD correlations beyond that with total body weight.

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.

Age-related changes in body composition and their relationship with bone mineral density decreasing rates in central south Chinese postmenopausal women

The purpose of this work is to investigate the age-related changes in body composition and their relationship with bone mineral density decreasing rates (BDR) in central south Chinese postmenopausal women. BDR is the percentage of bone mineral density (BMD) decreasing value relative to the peak bone mass. A cross-sectional study was conducted on 779 healthy postmenopausal women, aged 50-77. Lumbar spine, total hip, and femoral neck BMD and body composition were measured by dual-energy X-ray absorptiometry. In women under 65, lean mass levels showed a stable downward trend, and were significantly higher than those of the 65-70 and >70 age groups; however, the fat mass levels showed no significant difference between the age groups. After controlling for age, age at menopause, and height, both fat mass and lean mass positively correlated with BDR at the lumbar1-4 spine, the femoral neck and the total hip. When BDR at the lumbar1-4 spine was used as the dependent variable, a higher R (2) change and partial R (2) were seen in fat mass than the age, age at menopause or lean mass, indicating that fat mass was the most significant determinant of BDR at this site. When BDR at the femoral neck or total hip was used as the dependent variable, respectively, lean mass was a more significant determinant than that of fat mass. We found that with advancing age, lean mass begins to decrease in women aged over 65 years, but fat mass levels show no significant difference between the age groups. Both fat mass and lean mass positively correlate with BDR, with site-specific differences. Fat mass is the most significant determinant of BDR at the lumbar spine, whereas lean mass is the most significant determinant of BDR at the femoral neck and total hip.

The associations of body composition and fat distribution with bone mineral density in elderly Italian men and women

This study aimed to investigate the associations of body composition and fat distribution with bone mineral density (BMD) in elderly Italian subjects. In 866 women (age 64.2±6.5yr) and 168 men (age 65.1±6.1yr), we measured BMD at lumbar spine, at femur, at the total body, and at the right hand. In all subjects, we also measured sex hormones, 25-hydroxyvitamin D, bone markers, and calcium intake. In both men and women, all body composition parameters had significant positive correlations with BMD at all sites after adjusting for age only; after adjusting also for body weight only lean mass (LM) remained positively associated with BMD at all sites except BMD at lumbar spine. In males, LM was associated with BMD at all sites, whereas android fat was associated with BMD at lumbar spine, at femur, and at whole body. In females, fat mass (FM) was positively and age inversely associated with BMD at all sites, whereas gynoid fat and alkaline phosphatase were inversely associated with BMD at lumbar spine and at femur. In conclusion, the role of LM seems more important in males, whereas in women the role of FM prevails with negative associations between gynoid fat and BMD.

Effect of fat mass and lean mass on bone mineral density in postmenopausal and perimenopausal Thai women

BACKGROUND

The purpose of this study was to investigate the association between fat mass, lean mass, and bone mineral density (BMD) in postmenopausal and perimenopausal Thai women.

METHODS

A cross-sectional study was conducted in 1579 healthy Thai women aged 40-90 years. Total body, lumbar spine, total femur, and femoral neck BMD and body composition were measured by dual x-ray absorptiometry. To evaluate the associations between fat mass and lean mass and various measures of BMD, multivariable linear regression models were used to estimate the regression coefficients for fat mass and lean mass, first in separate equations and then with both fat mass and lean mass in the same equation.

RESULTS

Among the study population, 1448 subjects (91.7%) were postmenopausal and 131 (8.3%) were perimenopausal. In postmenopausal women, after controlling for age, height, and duration of menopause, both fat mass and lean mass were positively correlated with BMD when they were analyzed independently of each other. When included in the same equation, both fat mass and lean mass continued to show a positive effect, but lean mass had a significantly greater impact on BMD than fat mass at all regions except for total body. Lean mass but not fat mass had a positive effect on BMD at all skeletal sites except the lumbar spine, after controlling for age and height in perimenopausal women.

CONCLUSION

Lean mass had a significant beneficial effect on BMD in both postmenopausal and perimenopausal women and can be considered as one of the determinants of bone mass. The effect of the fat mass was related to menopausal status, but only demonstrated a positive impact in perimenopausal women.

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.