Relationship between body composition and bone mineral density in women with and without osteoporosis: relative contribution of lean and fat mass

Different contributions of fat and lean indices to bone strength by sex

Bone strength depends on both bone density and quality. However, the differences in how body composition indices affect bone strength between men and women remains unclear. This study investigated the associations of various fat and lean indices with bone strength by sex. In this cross-sectional study involving 1,419 participants, bone mineral density (BMD) and body composition were measured using dual-energy X-ray absorptiometry. Bone quality was assessed using the trabecular bone score (TBS). Fat indices included total fat mass, body fat percentage, and waist circumference, while lean indices included appendicular lean mass (ALM) and hand grip strength. All fat indices demonstrated a positive association with BMD and a negative association with the TBS in both men and women. Fat indices were more strongly associated with BMD in women than in men. Furthermore, lean indices contributed more to BMD in men than in women. In women, ALM contributed more to BMD than hand grip strength, whereas in men, hand grip strength had a greater impact on BMD than ALM. Hand grip strength was also positively associated with the TBS in men. Overall, fat indices had a greater influence on BMD in women, while lean indices were more positively associated with bone strength in men. Considering different fat indices, ALM was more strongly associated with BMD in women, whereas hand grip strength played a greater role in men. Thus, maintaining both muscle mass and strength is crucial for preserving bone mass.

Relationship between Femur Mineral Content and Local Muscle Strength and Mass

Among the stimuli able to prevent early decreases in bone mineralization, exercise has a noticeable role per se as the source of mechanical stimulus or through lean tissue enlargement by its increasing of tensional stimulus. However, prevention strategies, including exercise, generally do not establish the moment in life when attention should begin to be paid to bone integrity, according to age group- and sex-related differences. Thus, this study analyzed the relationship between variables from the diagnosis of total and regional body composition, muscle strength, and bone mineral content (BMC) of femurs in young adult males. Thirty-four young Caucasian men (24.9 ± 8.6 years) had their body composition and bone density assessed by dual X-ray absorptiometry. The subjects performed a one-repetition maximum test (1-RM) in a bench press, front pulley, seated-row, push press, arm curl, triceps pulley, leg flexion, leg extension, and 45° leg press for the assessment of muscle strength in upper and lower limbs in single- and multi-joint exercises. Lean tissue mass in the trunk and upper and lower limbs were related to femoral BMC (Pearson coefficient ranging from 0.55 to 0.72, p < 0.01), and 1-RM values for different exercises involving both upper and lower limbs also correlated with femoral BMC (Pearson coefficients ranging from 0.34 to 0.46, p < 0.05). Taken together, these correlations suggest that muscle mass and strength are positively linked with the magnitude of femoral mass in men, even in early adulthood. Hence, the importance of an enhanced muscle mass and strength to the health of femoral bones in young adults was highlighted.

Effect of the body mass index, basal metabolic rate, and body fat on the radiofrequency echographic multi-spectrometry (REMS)-based bone mineral density and fracture risk: a cross-sectional study

Radiofrequency echographic multi-spectrometry (REMS) is a method to assess bone mineral density (BMD) of the axial skeleton, fragility score (FS), body mass index (BMI), basal metabolic rate (BMR), and body fat (BF) in %. The aim of the study was to investigate the influence of the BMI, BMR, and BF on the BMD and fracture risk with REMS. We conducted a cross-sectional study among 313 women, aged 20-90 years who underwent a screening for osteoporosis with REMS. Kruskal-Wallis was used to analyze the differences in BMI, BMR, and BF between the groups according to the BMD: normal BMD, osteopenia and osteoporosis and differences in the FS, fracture risk assessment (FRAX) for major osteoporotic fractures and for hip fractures (HF) according to the BMI groups: underweight, normal weight, overweight, obese, and extreme obese. Linear regression was used to assess the correlations BMI-BMD, BMR-BMD, and BF-BMD. BMI, BMR, and BF differed significantly between the groups according to the BMD (p < 0.001, p = 0.028, and p < 0.001, respectively). BMR showed high positive correlation to BMD (R = 0.765) with 95% confidence interval (CI) [0.715, 0.807] and significance of p < 0.001. BMI correlated significantly to BMD (p < 0.001), the correlation was low positive (R = 0.362) with 95% CI [0.262, 0.455]. In the BMI groups, there was significant difference in FRAX for HF and FS with p value 0.014 and < 0.001, respectively. Subjects with low BMI, BMR, and BF are at high risk for osteoporosis. Underweight women show significantly high fracture risk, assessed with FRAX and FS.

Efficacy and tolerability of a specific blend of amino acids in patients with anorexia nervosa treated in a hospital setting: study protocol for a randomized controlled trial

BACKGROUND

Specific blends of essential amino acids (EAA) containing a high percentage of branched-chain amino acids preserves mitochondrial metabolism and higher physical resistance in elderly mice, increasing their survival and improving physical performance and cognitive functions in malnourished elderly patients. However, no study has been yet done on patients with anorexia nervosa (AN) who regain weight with specialized intensive treatment. The present study aims to evaluate the efficacy of supplementation with EAA on the change in lean body mass (LBM) and other physical and psychological outcomes in patients with AN who are undergoing specialist treatment for eating disorders.

METHODS

This is a 13-week randomized, double-blind, placebo-controlled study. Patients will be randomized to either a mixture of a complex blend of EAA and intermediates of the tricarboxylic acid (TCA) cycle (citrate, malate, succinate) supplementation (or placebo) upon admission at the intensive residential and day-hospital treatment for eating disorders. Ninety-two participants with AN aged 16-50 years will be recruited from a specialized intensive treatment of eating disorders. Double-blind assessment will be conducted at baseline (T0) and the end of the 13 weeks of treatment (T1). The study's primary aim is to evaluate the efficacy of supplementation with EAA and TCA intermediates on the change in lean body mass (LBM) with weight restoration in patients with AN who are undergoing specialist treatment for eating disorders. The secondary aims of the study are to assess the effect of dietary supplementation on physical fitness, weight restoration, modification of AN and general psychopathology, and psychosocial impairment.

DISCUSSION

The study's results will inform researchers and clinicians on whether supplementing a mixture of EAA and TCA cycle intermediates will improve the increase of LBM and other important physical and psychological outcomes in patients with AN who regain weight with specialized intensive treatment.

TRIAL REGISTRATION

NCT, NCT05290285. Registered on 22 March 2022.

Changes in bone quality after switching from a TDF to a TAF based ART: A pilot randomized study

BACKGROUND

The impact of tenofovir disoproxil fumarate (TDF) antiretroviral (ART) regimens on bone health has been characterized mostly by bone mineral density (BMD), but recently also by bone quality (BQ). The aim of this pilot study is to assess the changes in BMD and BQ after switch from TDF to tenofovir alafenamide (TAF) ART.

METHODS

HIV individuals receiving TDF-based ART were randomized to switch to Bictegravir-TAF-Emtricitabine or to remain in the same regimen. At baseline and 24-weeks after randomization, participants underwent bone mineral density (BMD) by DXA and BQ assessment using bone microindentation, a validated technique that measures bone tissue quality expressed as bone material strength index (BMSi). A panel of plasma bone turnover biomarkers were measured by ELISA at the same time-points. Values are expressed as median [interquartile range] and non-parametric tests were used where appropriate.

RESULTS

A total of 24 HIV individuals were included in the study, 19 of which were men (80%). Median age at baseline was 43 years (IQR 38-54). Half of individuals were allocated in the TDF group while the other half changed to TAF treatment. No differences at baseline between both groups were detected in any parameter. Non-significant changes nor in lumbar or femoral BMD at week 24 was found in any regimen. In contrast, there was an increase in BMSi in the TAF arm at 24 weeks, and thus an improvement in BQ[81.6 (79-83) to 86 (80-88) (+5.1%);p=0.041], whereas the TDF arm remained stable from 82 (76-85) at baseline to 82 (73-83);p=0.812. Hence, at week 24 there were significant differences in BQ between arms (p=0.049). A reduction in bone formation markers was found at week 24 in both regimens: N-terminal propeptide of type-1 collagen decreased a 20% (-35 - -0.6); p=0.031 with TAF and -16% (-25 - -5); p=0.032 with TDF. Also a decrease in bone resorption marker C-telopeptide with TAF was detected [-10% (-19 - -5);p=0.028] but not with TDF (p=0.232), suggesting a less metabolically active bone after switching to TAF.

CONCLUSION

A bone quality improvement was found after switching from a TDF to a TAF based ART independently of BMD, suggesting that the bone health benefits of TAF may extend beyond BMD. Future research should be directed to confirm these findings and to identify the underlying mechanisms of ART related bone toxicity.

The effect of the exercise environment and the level of involvement on bone mineral health

INTRODUCTION

This study aimed to compare athletes practicing exercise in different environments with non-active young and elderly men and women regarding bone mineral density (BMD), hypothesizing that BMD values differ between athletes according to the environment of exercise practice, but those training in a low-gravitational environment have no different stimuli to BMD increasing if compared with healthy peers experiencing reduced exercise involvement, whatever the age group and sex.

MATERIALS AND METHODS

104 participants of both sexes were selected according to the environment of exercise practice [swimmers (N = 26) and judo fighters (N = 26)], and exercise level of involvement [non-active young (N = 26) and older adults (N = 26)]. Dual-energy X-ray absorptiometry provided BMD, lean mass, and fat mass (FM) for the whole body (WB), upper (UL), and lower limbs (LL).

RESULTS

For the BMD in WB, UL and LL no effects of group and sex were observed (p > 0.05). Post-hoc analyses detected higher values of BMD in UL for female swimmers compared to non-active older adults (p < 0.05), while judo fighters showed higher BMD in WB, UL, and LL than other participants whatever the sex (p < 0.01). Lower FM was observed for WB, UL, and LL when swimmers and judo fighters were compared to non-active young and older female peers (p < 0.01).

CONCLUSION

The findings emphasized that BMD stimuli with swimming are reduced when compared to judo, and despite the stimuli in swimming is not distinguishable from that affecting BMD in WB, UL and LL of non-active young, it is effective in differing BMD in UL among non-active older for women.

Novel Insight into the Relationship Between Muscle-Fat and Bone in Type 2 Diabetes Ranging from Normal Weight to Obesity

OBJECTIVE

Decreased bone mineral density (BMD) is a common complication in individuals with type 2 diabetes mellitus (T2DM). Body weight, mainly consisting of muscle and fat, is the main determinant of BMD and fracture risks but does not accurately describe nutritional status. Most studies suggest that skeletal muscle mass (SMM) promotes BMD, while body fat mass (BFM) decreases BMD. However, the combined effect of SMM and BFM on BMD is elusive. Thus, the study aims to explore the combined effect of fat and muscle by the ratio index SMM/BFM on BMD in T2DM.

METHODS

BFM and SMM were measured by the bioelectrical impedance analysis (BIA) method among 593 T2DM individuals ranging from normal weight and obesity. BMD was analyzed by DXA. Novel non-linear generalized additive models (GAMs) were used as the statistical analysis method.

RESULTS

The results demonstrated that BMD T score/Z score of both femur and lumbar vertebrae were significantly higher and waist-hip ratio (WHR) was significantly lower in the high SMM/BFM group of both normal weight and overweight groups in T2DM individuals. Hence, SMM/BFM might be a good factor indicating BMD in different weight ranges. Additionally, the relationship between muscle fat and BMD was not linear. Notably, this correlation was not influenced by hyperglycemia in T2DM since different analytic models adjusted with the age, gender, BMI and HbA1c were adopted in this study. Furthermore, the impact of trunk fat (central, visceral fat most) and non-trunk fat (peripheral, the sum of subcutaneous limb fat most) on BMD was inconsistent. BMD presented unlimited reduction with trunk BFM increasing, while sustaining minimal diminishment with non-trunk BFM accumulation.

CONCLUSION

Our study provided a novel viewpoint relationship between muscle-fat and bone, and SMM/BFM might be a potential biomarker for bone health and clinical treatments of diabetes and related metabolic syndromes.

Impact of Long-term, High-fat, and High-cholesterol Diet on Murine Vertebrae Bones

As the percentage of overweight individuals in the population rises, diseases associated with excess weight resulting from poor nutrition are becoming more and more widespread. So far, the influence of weight or nutrition on bone health has shown conflicting results. In the literature, the existing studies disagree about the effect of diet on bones. Therefore, this study investigated the impact of a long-term, high-fat, and high-cholesterol diet on the spine in a mouse model. Wild-type mice were randomly separated into two groups; one group received a high-fat and high-cholesterol diet, and a control group was fed with a regular diet since birth for a duration of 8 months. The first to fifth thoracic vertebrae were extracted and investigated using histology and micro-CT. Samples were analyzed regarding different parameters: percentage of bone structure compared to the whole vertebra and the amount and thickness of the trabeculae. Both methods of the analysis showed similar results. Diet did not have a significant impact on the bone density of the vertebrae. The micro-CT examination showed that the average bone percentage of the examined vertebra was 6% (p = 0.2330) higher in the control group compared to the diet group. The same tendency was demonstrated in histology even though with a smaller difference of only 5%. The results of both methods were comparable and showed trends for the influence of different diets but not significant impacts. In summary, this study showed that a high-fat and high-cholesterol diet has a slightly negative impact on bone density. In order to further analyze the effects of different diets on bone composition, structure, and density, additional long-term studies should be carried out, and more parameters such as movement and genetic factors should be analyzed. Furthermore, other parameters such as exercise and genetic factors that could have a secondary influence on obesity should be investigated.

Body Composition in Adolescents and Young Adults with Anorexia Nervosa: A Clinical Review

BACKGROUND

Anorexia nervosa is a serious health condition characterized by a significant low body weight and alteration in body composition components.

AIM

In the current paper, we aim to summarize the available literature concerning changes in body fat, lean, and bone masses, during anorexia nervosa and after complete weight restoration.

METHODS

Data were summarized using a narrative approach based on clinical expertise in the interpretation of the available evidence base in the literature.

RESULTS

The available data revealed three main findings. Firstly, anorexia nervosa causes a significant reduction in body fat mass, however it is completely restored after short-term weight normalization but with a central adiposity phenotype that does not seem to negatively influence treatment outcomes and appears to normalize after 1 year of normal weight maintenance. Secondly, anorexia nervosa causes a significant reduction in bone mineral density, but weight restoration is associated first (≈12 months) with stabilization of bone mineral density, followed by improvements (after ≈16 months); and finally, with complete normalization (after ≈30 months) after normal-weight maintenance. Thirdly, during anorexia nervosa loss of lean and skeletal body mass occurring in particular from the extremities rather than the central regions has been consistently reported, especially in patients with a Body Mass Index (BMI) ≤ 16.5 Kg/m2 however short-term weight restoration is associated with complete normalization.

CONCLUSION

Anorexia nervosa adversely affects body composition, however this medical complication seems to be reversible through the main treatment strategy of body weight restoration followed by normal weight maintenance, and this should be openly discussed with patients.

The Relationships Between Skeletal Muscle Index and Bone Variables in a Group of Young Adults

The purpose of this study was to investigate the relationships between skeletal muscle index (SMI) and bone variables in a group of young adults. Three hundred and thirty-five young adults (129 men and 206 women) whose ages ranged from 18 to 35 yr voluntarily participated in this study. Weight and height were measured, and body mass index (BMI) was calculated. Body composition, bone mineral content (BMC), bone mineral density (BMD), geometric indices of hip bone strength and trabecular bone score (TBS) were determined for each individual by Dual-energy X-ray absorptiometry (DXA). Appendicular skeletal mass (ASM, in kg) was calculated by summing the muscle masses of the 4 limbs, assuming that all nonfat and nonebone mass is skeletal muscle. Skeletal muscle index (SMI) was defined as ASM/height². In young men, SMI was positively correlated to WB BMC (r = 0.63; p < 0.001), WB BMD (r = 0.53; p < 0.001), L1-L4 BMC (r = 0.33; p < 0.001), L1-L4 BMD (r = 0.30; p < 0.001), L1-L4 TBS (r = 0.26; p < 0.01), TH BMC (r = 0.61; p < 0.001), TH BMD (r = 0.46; p < 0.001), FN BMC (r = 0.51; p < 0.001), FN BMD (r = 0.46; p < 0.001), FN cross-sectional area (CSA) (r = 0.56; p < 0.001), FN cross-sectional moment of inertia (CSMI) (r = 0.52; p < 0.001) and FN section modulus (Z) (r = 0.54; p < 0.001) but negatively correlated to FN strength index (SI) (r = -0.24; p < 0.01). In young women, SMI was positively correlated to WB BMC (r = 0.61; p < 0.001), WB BMD (r = 0.60; p < 0.001), L1-L4 BMC (r = 0.35; p < 0.001), L1-L4 BMD (r = 0.33; p < 0.001), L1-L4 TBS (r = 0.29; p < 0.001), TH BMC (r = 0.61; p < 0.001), TH BMD (r = 0.53; p < 0.001), FN BMC (r = 0.45; p < 0.001), FN BMD (r = 0.49; p < 0.001), FN CSA (r = 0.60; p < 0.001), FN CSMI (r = 0.52; p < 0.001), and FN Z (r = 0.40; p < 0.001) but negatively correlated to FN SI (r = -0.20; p < 0.01). The current study suggests that SMI is a positive determinant of bone mineral density and geometric indices of hip bone strength in young adults.

Bone Density and Body Fat Distribution in Postmenopausal Women

Background:

In postmenopause there are changes in metabolism of bone tissue and consequent decrease of bone density. With ageing redistribution of fat occurs and an increase in body weight. Because of hormone changes in postmenopause fat is redistributed from gluteofemoral area to the abdominal region.

Objective:

The objective of this study was to examine the relationship between bone density and a body mass index (BMI), and distribution of the fat tissue in women in postmenopause (WHR).

Methods:

This research was prospective, and it included total of 83 women, 53 women were in the natural postmenopause and 30 women with the regular menstruation.

Results:

BMI in women in postmenopause was statistically significantly higher than BMI in women with the regular menstruations (p= 0,005). There was no statistically significant difference between waist hip ratio in women in the postmenopause in relation to the women with the regular menstruations. In women in the postmenopause significant positive correlation between BMI and density of the neck of femur was found (Z and T-score) (p=0,019; p=0,005). There was also significant negative correlation between the WHR and density of the lumbal spine (backbone) in women in the postmenopause (Z-score) (p=0,043). The identical analysis in women with regular menstruations, negative correlation between the density of the lumbal spine was found again (Z-score) and WHR , but the same was highly expressed (p=0,041). The observed correlation between BMI and bone density in this group of women was not statistically significant.

Conclusion:

Based on the presented results we conclude that the higher the BMI (p=0,019; p=0,005) the higher density of the femoral neck postmenopausal women have, and lower bone density of the lumbar spine the higher ratio waist / hip (p = 0.043). In the women with regular menstruation bone density of the lumbar spine is the lower the higher the ratio of waist and hip (p=0,041), while there was no correlation between BMI and bone density in this group of women.

Lean body mass, body fat percentage, and handgrip strength as predictors of bone mineral density in postmenopausal women

Objective:

This study was conducted to assess lean body mass, body fat percentage, and handgrip strength in the prediction of bone mineral density (BMD) in postmenopausal women.

Materials and Methods:

This cross-sectional study included 102 postmenopausal women aged between 45 and 80 years (mean age 58) who were screened for osteoporosis using a dual-energy X-ray absorptiometry scan at the lumbar spine. The lean body mass, body fat percentage, and handgrip strength were calculated.

Results:

The lean body mass, body fat percentage, and handgrip strength were having a positive association (correlation coefficient: 0.48, 0.29, and 0.3, respectively) with BMD.

Conclusion:

Lean body mass, body fat percentage, and handgrip strength can detect early loss of BMD in postmenopausal women leading to early screening for osteoporosis resulting in early interventions minimizing BMD loss over a much longer period after menopause.

Repository Describing an Aging Population to Inform Physiologically Based Pharmacokinetic Models Considering Anatomical, Physiological, and Biological Age-Dependent Changes

BACKGROUND

Aging is characterized by anatomical, physiological, and biological changes that can impact drug kinetics. The elderly are often excluded from clinical trials and knowledge about drug kinetics and drug-drug interaction magnitudes is sparse. Physiologically based pharmacokinetic modeling can overcome this clinical limitation but detailed descriptions of the population characteristics are essential to adequately inform models.

OBJECTIVE

The objective of this study was to develop and verify a population database for aging Caucasians considering anatomical, physiological, and biological system parameters required to inform a physiologically based pharmacokinetic model that included population variability.

METHODS

A structured literature search was performed to analyze age-dependent changes of system parameters. All collated data were carefully analyzed, and descriptive mathematical equations were derived.

RESULTS

A total of 362 studies were found of which 318 studies were included in the analysis as they reported rich data for anthropometric parameters and specific organs (e.g., liver). Continuous functions could be derived for most system parameters describing a Caucasian population from 20 to 99 years of age with variability. Areas with sparse data were identified such as tissue composition, but knowledge gaps were filled with plausible qualified assumptions. The developed population was implemented in Matlab^® and estimated system parameters from 1000 virtual individuals were in accordance with independent observed data showing the robustness of the developed population.

CONCLUSIONS

The developed repository for aging subjects provides a singular specific source for key system parameters needed for physiologically based pharmacokinetic modeling and can in turn be used to investigate drug kinetics and drug-drug interaction magnitudes in the elderly.

Association between renal function and bone mineral density in healthy postmenopausal Chinese women

BACKGROUND

The relationship between renal function and bone mineral density (BMD) is controversial. The aim of this study was to determine the relationship of renal function with BMD and osteoporosis risk in healthy postmenopausal Chinese women.

METHODS

A cross-sectional study was conducted in 776 healthy postmenopausal Chinese women. Dual-energy X-ray absorptiometry was used to measure BMDs. Clinical, demographic, and biochemical data were obtained at the time of image acquisition. Estimated glomerular filtration rate (eGFR) was calculated using a Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

RESULTS

Women with eGFR levels of at least 90 ml/min/1.73m² had a lower prevalence of osteoporosis compared with women with decreased eGFR levels (60 ml/min/1.73 m² ≤ eGFR < 90.0 ml/min/1.73 m²). BMDs at femoral neck and total hip were significantly lower in the lower eGFR class than the higher class (0.717 ± 0.106 vs 0.744 ± 0.125 g/cm², P < 0.01; 0.796 ± 0.116 vs 0.823 ± 0.129 g/cm², P < 0.01, respectively). eGFR was positively correlated with BMDs at femoral neck and total hip in unadjusted analysis (P < 0.05). After controlling for age, menopausal duration and body mass index (BMI), decreased eGFR was not associated with osteoporosis risk.

CONCLUSIONS

After adjustments for age, menopausal duration and BMI, the decline in renal function was not independently associated with osteoporosis risk in healthy postmenopausal Chinese women.

Comparison of 14 body size variables on adult skeletal age methods: how body mass, BMI, fat and muscle influence age estimations

Background: Skeletal age estimations consistently under-age individuals with low body mass and over-age individuals with high body mass.Aim: To assess the directional biases of body size variables, including fat and muscle tissue, on skeletal age estimates.Subjects and methods: CT scans of 420 age- and size-selected cadavers were assessed using the fourth rib and pubic symphysis age estimation methods. MANCOVA was used to test the effects of stature, body mass, circumference, and fat and muscle tissue area on age estimation biases.Results: For both methods, there were biases based on body mass, BMI, circumference and fat tissue area. Individuals with the lowest measurements for these variables were under-aged while individuals with the highest measurements were over-aged. Age estimation biases were not affected by stature, muscle area, or skeletal measurements of bi-iliac breadth, femoral head diameter, or femoral length.Conclusion: Increased body mass, and specifically fat tissue, accelerates skeletal ageing. Increased muscle area generally did not show a protective effect on skeletal ageing. The accuracy of age estimations would be improved by factoring in body mass. However, femoral head diameter and bi-iliac breadth are not good proxies for body mass. Osteological markers of obesity offer a promising new approach.

WOMEN’S FEMORAL MASS CONTENT CORRELATES TO MUSCLE STRENGTH INDEPENDENTLY OF LEAN BODY MASS

ABSTRACT Introduction There is limited consensus regarding the recommendation of the most effective form of exercise for bone integrity, despite the fact that weight training exercise promotes an increase in muscle mass and strength as recurrent responses. However, strength variations in women do not depend on muscle mass development as they do in men, but strength enhancement has shown the potential to alter bone mineral content (BMC) for both sexes. Objective This study analyzed the potential of muscle strength, as well as that of whole-body and regional body composition, to associate femoral BMC in young women. Methods Fifteen female college students (aged 24.9 ± 7.2 years) were assessed for regional and whole-body composition using dual-energy X-ray absorptiometry (DXA). Maximum muscle strength was assessed by the one-repetition maximum (1RM) test in the following exercises: bench press (BP), lat pulldown (LP), knee flexion (KF), knee extension (KE) and 45° leg press (45LP). Linear regression analyzed BMC relationships with regional composition and 1RM values. Dispersion and error measures (R 2 aj and SEE), were tested, defining p ≤0.05. Results Among body composition variables, only total lean body mass was associated with femoral BMC values (R 2 aj = 0.37, SEE = 21.3 g). Regarding strength values, 1RM presented determination potential on femoral BMC in the CE exercise (R 2 aj = 0.46, SEE = 21.3 g). Conclusions Muscle strength aptitude in exercises for femoral regions is relevant to the femoral mineralization status, having associative potential that is similar to and independent of whole-body lean mass. Therefore, training routines to increase muscle strength in the femoral region are recommended. In addition, increasing muscle strength in different parts of the body may augment bone remodeling stimulus, since it can effectively alter total whole-body lean mass. Level of Evidence II; Development of diagnostic criteria in consecutive patients (with universally applied reference ‘‘gold’’ standard).

BONE HEALTH, MUSCLE STRENGTH AND LEAN MASS: RELATIONSHIPS AND EXERCISE RECOMMENDATIONS

ABSTRACT Although muscle strength, lean mass and bone mineral content/density (BMC/BMD) are consistently reported as major outcomes of resistance training (RT), there is still no agreement on the RT regimen that is capable of achieving this result in men and women of different ages. This study describes the effects of RT on muscle strength, lean mass and bone mineralization, highlighting the relationships between them and analyzing the effectiveness of the RT protocol. Information searches were conducted in open access online academic libraries, using the BMC/BMD indices combined with muscle strength, body composition, and resistance exercises. The results showed changes in BMC/BMD in 72% of the studies published in the last decade. Among these, 77% recommended loads ≥ 80% 1-RM, 61% involved older individuals (> 60 years) and 61% had planning protocols of between 3 and 5 months (~12-20 weeks). The results also highlight muscle strength as a promising index of variations in BMC/BMD, with a moderate to high level of association (r2>0.5), which are specific for men and women in relation to the body region with best responsiveness. Among the studies published in last decade, about 61% had protocols involving only RT, and of these, 82% observed combined changes in BMC/BMD, body composition and muscle strength. This review therefore concludes that RT is important for improving muscle strength, increasing lean mass (whole-body and regional) and preventing risk factors that could impair the mineral integrity of the bone tissue, in individuals of all ages and sexes. Level of Evidence I; Systematic review of Level I RCTs (and study results were homogenous).

Quantitative analysis of modified functional muscle-bone unit and back muscle density in patients with lumbar vertebral fracture in Chinese elderly men: a case-control study

OBJECTIVES

Bone mineral density (BMD) is associated with muscle mass and quality, but little research has been done on functional muscle-bone unit and back muscle density in patients with lumbar vertebral fracture. This study used the "modified functional muscle-bone unit" concept and measured back muscle density to investigate muscle-bone interaction difference between the fracture and control group.

METHODS

This was a case-control study. A total of 52 elderly male patients (mean age 75 years) with lumbar vertebral fracture (cases) and 52 control healthy subjects were enrolled. Cross-sectional area (CSA) and density of paravertebral muscle were measured in quantitative computed tomography (QCT) images to represent the muscle mass, while the bone mineral density measured by QCT was used to represent the bone mass. The modified functional muscle-bone unit was calculated as the value of volumetric BMD divided by muscle area.

RESULTS

People with vertebral fractures reported significantly lower values in the cross-sectional area and density of paravertebral muscle compared to control group. In the multivariate analysis, BMD (odds ratio, OR = 0.929; 95% confidence intervals, CIs 0.888-0.971), erector muscle density (OR = 0.698; 95% CI 0.547-0.892), and summated muscle CSA (OR = 0.963; 95% CI 0.93-0.991) were independent protective factors for the presence of a fracture. BMD resulted significantly and moderately associated with cross-sectional area and density of paravertebral muscle (r = 0.329-0.396).

CONCLUSIONS

There were significant differences between the modified functional muscle-bone unit and back muscle density between the fracture group and control group in elderly men. Lower BMD, loss of muscle mass and density are associated with increased presence of the lumbar vertebral fracture.

Body compositions differently contribute to BMD in different age and gender: a pilot study by QCT

The study was to investigate the correlation between body compositions and bone mineral density (BMD) and to evaluate the body composition contribution to BMD. In male, LM showed positive effect on BMD. In female, SAT showed positive, and FM and F/L showed negative effect on BMD.

PURPOSE

The purpose of the study was to investigate the correlation between body compositions and bone mineral density (BMD) performed by quantitative computed tomography (QCT), and to evaluate the body composition contribution to BMD.

METHODS

Three hundred ninety-four participants, including 122 male (31%) and 272 female (69%), were divided into groups by gender, age, and BMD. BMD and body compositions [including fat mass (FM), lean mass (LM), bone mass/lean mass ratio (B/L), fat mass/lean mass ratio (F/L), total adipose tissue (TAT), subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT)] were retrospectively compared among groups using one-way ANOVA or t test. A stepwise multivariate analysis was used to evaluate the body composition contribution to BMD and produced models.

RESULTS

In male, BMD got decreased with age (P < 0.05). LM increased before 30-49 years, then decreased (P < 0.05). TAT and SAT decreased with age (P < 0.05). LM in OP group was lower than those in the other two groups (P < 0.05). Through stepwise multivariate analysis, LM firstly got into model 1 (M1, β = 0.589). In female, BMD, LM TAT, and VAT were increased before 30-49 years, then decreased (P < 0.05). FM and F/L increased with age (P < 0.05). SAT decreased with age (P < 0.05). FM and F/L in OP group were higher than those in other groups. LM, B/L, TAT, and SAT in the OP group were lower than those in the other groups (P < 0.05). SAT entered the M1 with a maximum β value (β = 0.584).

CONCLUSIONS

BMD and body compositions displayed different characteristics with age. In male, LM showed positive effect on BMD. In female, SAT showed positive, and FM and F/L showed negative effect on BMD.

Lean Body Mass in the Prediction of Bone Mineral Density in Postmenopausal Women

Owing to conflicting results of the association between body composition and bone mineral density (BMD), we investigated the relationship between fat mass (FM), lean mass (LM), and BMD in New Zealand postmenopausal women. We hypothesized that increased LM will indicate a higher BMD. A cross-sectional study was performed examining the associations between body composition, anthropometric measures, activity energy expenditure, and bone health status (using dual-energy X-ray absorptiometry [DXA]). A total of 127 healthy postmenopausal women aged between 54 and 81 years. Both FM and LM were significantly associated with BMD at all sites. However, LM, not FM, was the strongest predictor of femoral neck (FN) BMD (β = 0.497, p < 0.001), hip BMD (β = 0.495, p < 0.001), spine BMD (β = 0.449, p < 0.001), and whole body BMD (β = 0.406, p < 0.001). Age was negatively associated with FN and hip BMD. LM was positively associated with FN, spine, hip, and whole body BMD. Our findings suggest the need to increase LM rather than FM highlighting the importance of physical activity for this age group.

Physical performance measures in screening for reduced lean body mass in adult females with obesity

BACKGROUND & AIMS

Little is known about the reduction of lean body mass (LBM) in obesity, or how to identify it in standard clinical settings. We therefore aimed to assess the prevalence of low LBM in adult females with obesity, and to identify the reliability of simple tools for its screening in this population.

METHODS AND RESULTS

Dual-energy X-ray absorptiometry (DXA) body composition assessment was used to categorise 147 female participants with obesity as with or without low LBM, according to the new definition that takes into account both appendicular lean mass (ALM) and body mass index (BMI)-ALM/BMI <0.512. Participants were also administered the six-minute walking test, handgrip-strength test and 4-metre gait-speed test. Of the sample of 147 participants, 93 (63.3%) met the criteria for reduced LBM. Stepwise multivariate logistic regression analysis showed that the six-minute walking test was the only independent test associated with low LBM (OR = 0.992, 95%CI 0.987-0.998). Receiver operating characteristic (ROC) curve analysis found that the discriminating cut-off points of the tests considered were 470 m, 3.30 s (gait speed = 1.2 m/sec) and 23.5 kg respectively; the 4-metre gait-speed test seems to provide the best balance of sensitivity and specificity, and the greatest discriminatory power at 90% sensitivity.

CONCLUSIONS

Treatment-seeking adult females with obesity display a great prevalence of reduced LBM. The six-minute walking test was the only independent test associated with low LBM, but the 4-metre gait-speed test seems to be the most accurate functional test for screening for this condition in that population.

Lean mass as a determinant of bone mineral density of proximal femur in postmenopausal women

OBJECTIVE

To verify which component of body composition (BC) has greater influence on postmenopausal women bone mineral density (BMD).

SUBJECTS AND METHODS

Four hundred and thirty women undergoing treatment for osteoporosis and 513 untreated women, except for calcium and vitamin D. Multiple linear regression analysis was performed in order to correlated BMD at lumbar spine (LS), total femur (FT), femoral neck (FN) with body mass (BM), total lean mass (LM) and total fat mass (FM), all determined by DXA.

RESULTS

BM significantly correlated with all bone sites in untreated and treated women (r = 0.420 vs 0.277 at LS; r = 0.490 vs 0.418 at FN, r = 0.496 vs 0.414 at FT, respectively). In untreated women, the LM correlated better than FM with all sites, explaining 179% of LS; 32.3% of FN and 30.2% of FT; whereas FM explained 13.2% of LS; 277% of FN, 23.4% of FT In treated women, correlations with BC were less relevant, with the LM explaining 6.7% of BMD at LS; 15.2% of FN, 16% of FT, whereas the FM explained 8.1% of LS; 179% of FN and 176% of FT.

CONCLUSION

LM in untreated women was better predictor of BMD than FM, especialy for distal femur, where it explained more than 30% of the BMD, suggesting that maintaining a healthy muscle mass may contribute to decrease osteoporosis risk. Treatment with anti-osteoporotic drugs seems to mask these relationships. Arch Endocrinol Metab. 2018;62(4):431-7.

Impact of cross-sex hormone therapy on bone mineral density and body composition in transwomen

OBJECTIVE

Cross-sex hormone therapy (CSHT) has been associated with changes in bone and lean/fat mass. This study assessed bone mineral density (BMD), appendicular lean mass (ALM), and total fat mass in transwomen undergoing CSHT.

PATIENTS AND DESIGN

We evaluated 142 transwomen (mean age: 33.7 ± 10.3 years; BMI: 25.4 ± 4.6; 86.6% with previous CSHT) during the first 3 months of regular oestrogen treatment (with or without anti-androgens). A reference group including 22 men and 17 cis women was also studied.

MEASUREMENTS

Clinical and hormonal evaluation and dual-energy X-ray absorptiometry (DXA).

RESULTS

Bone mineral density was similar in trans and reference women, and lower at all sites in transwomen vs men. Low bone mass for age was observed in 18% of transwomen at baseline vs none of the reference women or men. Appendicular lean mass and total fat mass were positively correlated with L1-L4 BMD, explaining 14.9% of the observed variation in lumbar spine BMD and 20.6% of the variation in total femur BMD. Appendicular lean mass was similar in trans and reference women, and lower in transwomen vs men. Total fat mass was lower in trans vs reference women. Densitometry was repeated after a mean of 31.3 ± 6.5 months in 46 transwomen. There was a significant increase in total fat mass and a significant decrease in ALM. Bone mineral density remained stable over time.

CONCLUSIONS

The fairly high prevalence of low bone mass in this sample of transwomen from southern Brazil seems to be related to lower ALM. Non-pharmacological lifestyle-related strategies for preventing bone loss could be beneficial for transgender women receiving long-term CSHT.

Association of High Anti-Cyclic Citrullinated Peptide Seropositivity and Lean Mass Index With Low Bone Mineral Density in Rheumatoid Arthritis

OBJECTIVE

Osteoporotic fractures are associated with high morbidity and mortality. Persons with rheumatoid arthritis (RA) have twice the risk of osteoporosis-related fracture than age-matched controls, the causes for which remain unknown. We investigated contributions of RA characteristics, medication use, and body composition to low bone mineral density (BMD) in patients with RA.

METHODS

Data were from the Arthritis, Body Composition, and Disability Study (n = 138; 82 women, 56 men). Demographic, clinical, laboratory, and functional variables were collected at study visits. Body composition (fat, lean muscle, and BMD) was measured by dual x-ray absorptiometry. Linear regression analyses evaluated the association between predictors and femoral neck BMD.

RESULTS

Average disease duration was 19 years, 70% of patients were rheumatoid factor positive, and 55% were high-positive anti-cyclic citrullinated peptide (anti-CCP). Age and high anti-CCP positivity were negatively associated with BMD after controlling for other variables (β = -0.003 and -0.055, respectively, P < 0.05). Appendicular lean mass index (ALMI) was positively associated with BMD (β = 0.053, P < 0.0001). In high anti-CCP positivity participants, increasing anti-CCP levels were associated with a negative linear trend in BMD (β = -0.011, P = 0.026).

CONCLUSION

High anti-CCP positivity and ALMI were strongly associated with BMD in patients with RA. The linear relationship of anti-CCP levels with lower BMD supports the hypothesis that processes specific to RA negatively impact BMD. In contrast, ALMI was positively associated with BMD, emphasizing the importance of this potentially modifiable risk factor. Our findings highlight the complicated interplay of RA disease-specific and functional factors and their impact on bone mass.

Distal radius microstructure and finite element bone strain are related to site-specific mechanical loading and areal bone mineral density in premenopausal women

While weight-bearing and resistive exercise modestly increases aBMD, the precise relationship between physical activity and bone microstructure, and strain in humans is not known. Previously, we established a voluntary upper-extremity loading model that assigns a person's target force based on their subject-specific, continuum FE-estimated radius bone strain. Here, our purpose was to quantify the inter-individual variability in radius microstructure and FE-estimated strain explained by site-specific mechanical loading history, and to determine whether variability in strain is captured by aBMD, a clinically relevant measure of bone density and fracture risk. Seventy-two women aged 21–40 were included in this cross-sectional analysis. High resolution peripheral quantitative computed tomography (HRpQCT) was used to measure macro- and micro-structure in the distal radius. Mean energy equivalent strain in the distal radius was calculated from continuum finite element models generated from clinical resolution CT images of the forearm. Areal BMD was used in a nonlinear regression model to predict FE strain. Hierarchical linear regression models were used to assess the predictive capability of intrinsic (age, height) and modifiable (body mass, grip strength, physical activity) predictors. Fifty-one percent of the variability in FE bone strain was explained by its relationship with aBMD, with higher density predicting lower strains. Age and height explained up to 31.6% of the variance in microstructural parameters. Body mass explained 9.1% and 10.0% of the variance in aBMD and bone strain, respectively, with higher body mass indicative of greater density. Overall, results suggest that meaningful differences in bone structure and strain can be predicted by subject characteristics.

•

Areal bone mineral density (aBMD) explains 51% of the variability in bone strain.

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Adult bone loading predicts greater cortical porosity and trabecular density.

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Greater body mass predicts greater aBMD and lower bone strain.

Positive Association of Obesity and Insulin Resistance With Bone Mineral Density in Tunisian Postmenopausal Women

The association of bone mineral density (BMD) with obesity and insulin resistance remains unclear. This study aimed to explore these associations in Tunisian menopausal women. Eighty-one postmenopausal women were recruited. Data were analyzed for obese (N = 57) and non-obese women (N = 24) and for insulin-resistant (N = 43) and non insulin-resistant women (N = 36). Anthropometric and biochemical parameters were recorded. BMD in different sites and body composition were measured using dual-energy X-ray absorptiometry. Higher BMD was observed in obese women than those non-obese in the left femur (p = 0.0067), right femur (p = 0.0108), total hip (p = 0.0077), and the whole body (p = 0.0276). Also BMD was significantly greater in insulin-resistant women than in non-insulin-resistant women when measured in the left femur and total hip. Positive correlations were recorded between BMD and anthropometric parameters, body composition parameters, and glycemia (r = 0.249, p < 0.05). Multiple linear regression analysis shows that only trunk fat (p < 0.05) and lean mass (p < 0.05) were independently and positively related to BMD, and the waist circumference was the only anthropometric parameter independently and negatively associated to BMD. BMD is improved in obese and insulin-resistant women. Also, trunk fat and lean mass are likely to be key positive independent factors for BMD.

The relationship between osteoporosis and body composition in pre- and postmenopausal women from different ethnic groups in China

OBJECTIVE

To investigate the ethnic differences in osteoporosis (OP) and body composition (BC) and their relationship in the Maonan, Mulam, Hmong, and Yao minorities in China.

DESIGN

A total of 860 Maonan, Mulam, Hmong, and Yao women were included in this cross-sectional study. Demographic, health history, and lifestyle information was collected using questionnaires. BC was measured through bioelectrical impedance analysis, and bone mineral density (BMD) was assessed via calcaneal quantitative ultrasound.

RESULTS

Compared with premenopausal women, postmenopausal women exhibited a lower fat-free mass (FFM), muscle mass (MM), limb muscle mass, and T-score but a higher waist-to-hip ratio and prevalence of OP in each minority (p < .05). After adjustment for age, Hmong women displayed the highest body mass index, fat mass, percentage of body fat, visceral fat, and subcutaneous fat contents, while Yao women presented the highest T-scores and lowest prevalence of OP among the four minorities (p < .05). Having a greater number of children and an older age were significant risk factors for OP in all ethnic groups (p < .05, OR > 1). In addition, our results revealed that FFM and MM exhibited exactly the same weak positive relationship with the T-score (r = 0.081, p < .05) after adjusting for menopausal status and age in all of the participants. Furthermore, significant ethnic differences in the relationship between BC and the T-score existed in the four minorities studied here.

CONCLUSIONS

BC and OP prevalence varied by menopausal status and ethnic group, and ethnic-specific relationships between BC and BMD were present in the four minorities. More research is needed to further investigate the ethnic differences in BC, OP, and risk factors for lower BMD to develop targeted prevention strategies to reduce the burden of OP across different ethnic groups in China.

Discordance between fat mass index and body mass index is associated with reduced bone mineral density in women but not in men: the Busselton Healthy Ageing Study

The obesity-BMD relationship is complex. In 3045 middle-aged adults, we found that in women (but not men) with discordant fat mass index (FMI)/BMI categories, higher body fat for BMI was associated with lower BMD, suggesting that increased fat mass without an accompanying increase in lean mass may be deleterious to bone.

INTRODUCTION

The relationship between obesity and BMD is complex. FMI (fat mass (kg) / height (m)²) is a more accurate measure of fatness than BMI, and depending on body composition, some individuals have discordant BMI/FMI categories. We examined associations between FMI, BMI and BMD in participants in the Busselton Healthy Ageing Study.

METHODS

Body composition and BMD of the hip, spine and total body were measured using DXA in 3045 participants (1644 females) aged 45-67 years. Using standard BMI/FMI categories, the participants were classified as underweight/fat deficit, normal, overweight/excess fat, obese I and obese II-III.

RESULTS

BMI and FMI categories were concordant in 77.3 % of females and 71.2 % of males. There were 12.9 % females and 13.2 % males in a higher FMI than BMI category (high body fat for BMI), whereas 9.8 % females and 15.6 % males were in a lower category (low body fat for BMI). Females with high body fat for BMI had significantly lower covariate-adjusted BMD at the femoral neck, total hip and total body (differences of 3.8, 5.1 and 2.6 %, respectively, all P < 0.05) than females with low body fat for BMI and lower total body BMD than women with concordant FMI/BMI (by 1.4 %, P = 0.04). In males, BMD did not differ significantly between those who were concordant or discordant for FMI/BMI categories.

CONCLUSION

In women (but not men) with discordant FMI/BMI categories, higher body fat for BMI was associated with lower BMD, suggesting that increased fat mass without an accompanying increase in lean mass may be deleterious to bone.

Bone Mineral Density and Body Composition are Associated with Circulating Angiogenic Factors in Post-menopausal Women

Lean mass (LM) and fat mass (FM) are closely related to bone mass (BM) in post-menopausal women, although their relative importance is unclear. Angiogenic factors which control angiogenesis may influence BM, LM and FM. The aim of the study was to compare the contribution of LM and FM to bone mineral density (BMD) and the association between these tissues and circulating angiogenic factors. The study population comprised of 392 post-menopausal women aged mean [SD] 61.8 [6.4] years. BMD was measured at the lumbar spine (LS), neck of femur and total hip (TH) by dual-energy X-ray absorptiometry (DXA). DXA scan was also used to determine LM and FM. Angiopoietin-1 and 2 (ANG-1, ANG-2) were measured by sandwich enzyme-linked immunosorbent assay. Following adjustment for confounders, significant positive independent associations were seen between LM with BMD at all skeletal sites (TH: p < 0.0001) and FM with BMD at the hip sites (TH: p = 0.004). When BMD and LM were regressed against the angiogenic factors, positive associations were seen between ANG-2 with LM (p = 0.002) and LS BMD (p = 0.05). Negative associations were observed between the ratio of ANG-1/ANG-2 with LS BMD (p = 0.014), TH BMD (p = 0.049) and LM (p = 0.029). FM and fat distribution (android/gynoid fat ratio) were negatively associated with ANG-1 (p = 0.006) and ANG-2 (p = 0.004), respectively. ANG-1 and ANG-2 may be involved in the maintenance of bone, muscle and fat mass.

The Association between Trunk Body Composition and Spinal Bone Mineral Density in Korean Males versus Females: a Farmers' Cohort for Agricultural Work-Related Musculoskeletal Disorders (FARM) Study

The purpose of this study was proposed to identify the association of trunk body composition with spinal bone mineral density (BMD) in Korean male and female farmers. A total of 523 Korean farmers (259 males, 44 premenopausal females, and 220 postmenopausal females) were recruited. Computed tomography scans were acquired at the mid-L4 vertebral level, and total trunk muscle mass (TMM, cm³), back muscle mass (BMM), and abdominal wall muscle mass (AMM), total trunk fat mass (TFM), visceral fat mass (VFM), and subcutaneous fat mass (SFM) were assessed. Spinal BMD (g/cm²) was estimated from dual-energy X-ray absorptiometry at the L4 level. In terms of muscle mass, spinal BMD was significantly correlated with all the components of the trunk muscle mass (r = 0.171-0.360; P < 0.05, P < 0.001) in female farmers, while only with AMM (r = 0.181; P < 0.01) in male farmers. In terms of fat mass, spinal BMD was significantly correlated with all components of the trunk fat mass (r = 0.142-0.424; P < 0.05, P < 0.001) in male and premenopausal female farmers, while only with VFM (r = 0.132; P < 0.05) in postmenopausal females. Adjusted multivariate regression analysis showed that AMM in male and post-menopausal female farmers was closely associated with spinal BMD. There may be positive associations between trunk muscle and fat mass and spinal BMD with sexual dimorphism, and abdominal wall muscle mass was an explanatory variable closely related to spinal BMD in Korean farmers. Registered at the Clinical Research Information Service (CRIS, http://cris.nih.go.kr), number KCT0000829.

A comparison of bone mineral densities and body composition between Southeast Asia college students and Chinese college students

The aim of this study was to compare bone mineral densities (BMDs) and body composition between Southeast Asia college students and Chinese college students, in order to provide a certain reference enhancing college students' physical fitness.A total of 1694 Chinese college students (294 men and 1400 women, aged 18-22 years) and 250 Southeast Asia college students (148 men and 102 women, aged 19-22 years) were included in the study. Weight, height, and body mass index were measured anthropometrically. BMD values were determined by ultrasound bone densitometer and body composition was determined by body composition analyzer.Southeast Asia college students were overweight than Chinese college students (250 vs 1694) (P < 0.05). Chinese college students had a significantly lower body weight, fat mass, lean tissue mass, lean body weight, estimation of bone mass, protein, and metabolic rate but higher BMD at the calcaneus compared with Southeast Asia college students (P < 0.05 for all parameters). However, body water, intracellular fluid, and extracellular fluid were not significantly different between Chinese college students and Southeast Asia college students (P > 0.01 for all parameters).The results of this cross-sectional study suggest that Chinese college students had a higher BMD but lower body composition than Southeast Asia college students, which may be associated with genes, diet, exercise, and other factors.

Variations in fat mass contribution to bone mineral density by gender, age, and body mass index: the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2011

The relationship of body composition and bone mineral density is complex and controversial. When classifying Korean population based on gender, age, and body mass index, fat mass had varying contributions to bone mineral density.

INTRODUCTION

The relationship between body composition and bone mineral density (BMD) is complex, and it is uncertain how components of body mass variably affect BMD.

METHODS

This cross-sectional observational study was performed in subjects ≥20 years based on the Korea National Health and Nutrition Examination Survey (KNHANES) 2008 to 2011. Among 17,583 subjects, the mean ages were 49.1 ± 16.0 years (M, n = 7495) and 49.3 ± 16.3 years (F, n = 10,088). Subjects were divided into age groups, either <50 or ≥50 years for males, or menopausal state, either premenopausal or postmenopausal, for females. A further classification used BMI, either <25 or ≥25 kg/m(2). Anthropometric and body composition parameters were compared and evaluated to look for correlations with BMD. Further, appendicular lean mass (ALM), fat mass (FM), fat percentage (FP), and waist circumference (WC) were included for multivariate analysis with BMD, controlling for covariates in each age group and BMI subgroup.

RESULTS

Anthropometric and body composition parameters significantly correlated with BMD in all age groups for both genders. After adjusting for covariates, ALM strongly affected BMD in all age groups for both genders. FM, FP, and WC significantly affected BMD in both age groups of women and in older men, but they did not affect BMD in younger men. Fat indices positively affected BMD of all sites in all non-obese women and in non-obese older men. However, little contribution was found in obese subgroups of both genders and in non-obese younger men.

CONCLUSION

Considering different weights of covariates, ALM strongly contributed to BMD in all gender, age, and BMI groups. On the other hand, fat indices positively affected BMD of both age groups in women and older men with normal BMI, but they showed little contribution to BMD within the same age groups with high BMI or any BMI subgroups of younger men.

Association of sarcopenia and physical activity with femur bone mineral density in elderly women

[Purpose]

This study examined the association of femur bone mineral density (BMD) with body composition and physical activity in elderly women.

[Methods]

This was a cross sectional study involving 119 women with mean age of 73.1±5.5 years. Body composition parameters including body mass index (BMI), percent of body fat (%BF), appendicular skeletal muscle mass (ASM) index and femur BMD was measured by dual-energy X-ray absorptiometry (DXA). Physical activity was assessed by the uniaxial accelerometer for 7 consecutive days including weekends. Based on femur BMD T-scores, subjects were classified as optimal group, osteopenia group, and osteoporosis group. Based on ASM index, subjects were classified as normal group and sarcopenia group. According to WHO recommendations of physical activity for elderly, the subjects were classified as active group or inactive group. Logistic regression analyses were used to determine the odds ratio (OR) for osteopenia and osteoporosis.

[Results]

There were linear decreases for body composition parameters including weight (P=.023), BMI (P=.039), lean mass (P=.032), ASM index (P=.007) and physical activity parameters including daily of step (P<.001), low intensity physical activity (P<.001), moderate intensity physical activity (P=.001) across femur BMD levels. Compared to the normal group (OR=1), the sarcopenia group had a significantly higher OR (OR=4.823; P=.042), and the inactive group had a significantly higher OR (OR=5.478; P=.005) having osteopenia and osteoporosis when compared to the active group (OR=1).

[Conclusion]

The findings of this study suggested that physical activity along with a healthy nutrition should be promoted as a preventive strategy against osteopenia and osteoporosis in elderly women.

Assessment of Fat distribution and Bone quality with Trabecular Bone Score (TBS) in Healthy Chinese Men

Whether fat is beneficial or detrimental to bones is still controversial, which may be due to inequivalence of the fat mass. Our objective is to define the effect of body fat and its distribution on bone quality in healthy Chinese men. A total of 228 men, aged from 38 to 89 years, were recruited. BMD, trabecular bone score (TBS), and body fat distribution were measured by dual-energy X-ray absorptiometry. Subcutaneous and visceral fat were assessed by MRI. In the Pearson correlation analysis, lumbar spine BMD exhibited positive associations with total and all regional fat depots, regardless of the fat distribution. However, the correlation disappeared with adjusted covariables of age, BMI, HDL-C, and HbA1c%. TBS was negatively correlated with fat mass. In multiple linear regression models, android fat (and not gynoid, trunk, or limbs fat) showed significant inverse association with TBS (β = −0.611, P < 0.001). Furthermore, visceral fat was described as a pathogenic fat harmful to TBS, even after adjusting for age and BMI (β = −0.280, P = 0.017). Our findings suggested that body fat mass, especially android fat and visceral fat, may have negative effects on bone microstructure; whereas body fat mass contributes to BMD through mechanical loading.

Regional body fat depots differently affect bone microarchitecture in postmenopausal Korean women

SUMMARY

In a prospective community-based cohort study, we investigated the relationship between trabecular bone score (TBS) and regional fat depots in 1474 Korean postmenopausal women. TBS was positively related with subcutaneous fat and negatively related with visceral fat.

INTRODUCTION

The effect of fat distribution (visceral/subcutaneous) on bone quality or microarchitecture has rarely been investigated due to measurement difficulty. We aimed to investigate the relationship between TBS reflecting bone microarchitecture and regional fat depots in Korean women.

METHODS

Cross-sectional data evaluation was made from subjects participating in an ongoing prospective community-based cohort study since 2001. A total of 1474 postmenopausal women in the Ansung cohort were analyzed. Regional body fat mass, bone mineral density (BMD) at the lumbar spine, and total hip and lumbar spine TBS were measured by dual energy X-ray absorptiometry (DXA).

RESULTS

In an age-adjusted partial correlation analysis, TBS was not associated with total fat mass, but negatively associated with trunk fat mass. However, TBS was positively related with leg (r = 0.102, P < 0.05) and gynoid fat mass (r = 0.086, P < 0.05) and negatively related with android fat mass (r = -0.106; P < 0.05). In linear regression models controlling age, BMI, and physical activity, android fat was inversely associated with TBS (β = -0.595, P < 0.001), whereas gynoid fat was positively associated with TBS (β = 0.216, P < 0.001). Lumbar spine and total hip BMDs revealed positive associations with total and all regional fat depots regardless of fat distribution.

CONCLUSION

Our findings suggest that relatively large visceral fat and small subcutaneous fat may have a detrimental effect on TBS, a bone microarchitecture index.

Relationship of sarcopenia and body composition with osteoporosis

The purpose of the study is to investigate the relationship between sarcopenia and body composition and osteoporosis in cohorts of three different races with a total of 17,891 subjects. Lean mass and grip strength were positively associated with bone mineral densities (BMDs). Subjects with sarcopenia were two times more likely to have osteoporosis compared with normal subjects.

INTRODUCTION

The relationship between sarcopenia and osteoporosis is not totally clear. First, the present study assessed this relationship by using two different definitions for sarcopenia. Second, we examined the associations of body composition (including muscle mass as a major and important component) and muscle strength on regional and whole-body BMDs.

METHODS

In total, 17,891 subjects of African American, Caucasian, and Chinese ethnicities were analyzed. Sarcopenia was defined by relative appendicular skeletal muscle mass (RASM) cut points and also by the definition of the European Working Group on Sarcopenia in Older People (low RASM plus low muscle function). Multiple regression analyses were conducted to examine the association of fat mass, lean mass (including muscle mass), and grip strength with regional and whole-body BMDs. Multivariate logistic regression analysis was performed to explore the association between sarcopenia and osteopenia/osteoporosis.

RESULTS

BMDs were positively associated with lean mass and negatively associated with fat mass, after controlling for potential confounders. Grip strength was significantly associated with higher BMDs. Each standard deviation (SD) increase in RASM resulted in a ~37 % reduction in risk of osteopenia/osteoporosis (odds ratio (OR) = 0.63; 95 % confidence interval (CI) = 0.59, 0.66). Subjects with sarcopenia defined by RASM were two times more likely to have osteopenia/osteoporosis compared with the normal subjects (OR = 2.04; 95 % CI = 1.61, 2.60). Similarly, subjects with sarcopenia (low muscle mass and low grip strength) were ~1.8 times more likely to have osteopenia/osteoporosis than normal subjects (OR = 1.87; 95 % CI = 1.09, 3.20).

CONCLUSIONS

High lean mass and muscle strength were positively associated with BMDs. Sarcopenia is associated with low BMD and osteoporosis.

Fat Infiltration in the Leg is Associated with Bone Geometry and Physical Function in Healthy Older Women

The objective of this study was to estimate the associations between muscular fat infiltration, tibia bone mineral quantity and distribution, and physical function in healthy older women. Thirty-five women (aged 60-75 years, mean 70 years) were recruited from the community. Percent intramuscular fat (%IntraMF) within the right leg tibialis anterior, soleus, and gastrocnemius muscles and total intermuscular fat (IMF) were segmented from magnetic resonance imaging scans at the mid-calf. Intramyocellular lipid (IMCL) content in the right tibialis anterior was measured with proton magnetic resonance spectroscopy. Right tibia bone content, area, and strength were measured at the 4, 14, and 66% sites using peripheral quantitative computed tomography. Physical function was assessed by gait speed on the 20 m walking test. After adjusting for age, body size, and activity level, %IntraMF had a negative association with bone content and area at all tibia sites (r = -0.31 to -0.03). Conversely, greater IMF was associated with increased bone content and area (r = 0.04-0.32). Correlation coefficients for the association between IMCL and bone were negative (r = -0.44 to -0.03). All measures of fat infiltration had a negative association with observed physical function (r = -0.42 to -0.04). Our findings suggest that muscular fat infiltration in the leg of healthy postmenopausal women has a compartment-specific relationship with bone status and physical function. Minimizing fat accumulation within and between muscle compartments may prevent bone fragility and functional decline in women.

Associations of Bone Mineral Density with Lean Mass, Fat Mass, and Dietary Patterns in Postmenopausal Chinese Women: A 2-Year Prospective Study

Objective

To assess factors associated with bone mineral density (BMD) in postmenopausal women in a longitudinal study, and to examine the relative contribution of lean mass, fat mass, dietary patterns, and years since menopause to BMD.

Methods

Two hundred and eighty-two postmenopausal women were randomly selected from Hongqi Community Health Center, in Harbin City, China. All participants were followed up from 2009 to 2011. Dietary data were collected using a Food Frequency Questionnaire. BMD of the left hip, the lumbar spine, and the total body, and the body composition were measured by dual-energy X-ray absorptiometry at baseline and follow-up.

Results

Lean mass and fat mass were positively associated with BMD of the spine, hip, and the total body at both baseline and follow-up. The association between fat mass and BMD at the spine at baseline (P = 0.210) and at the spine (P = 0.116) and hip (P = 0.073) in the second year was not statistically significant when height was adjusted. Six dietary patterns were identified but only cereal grains-fruits pattern (P = 0.001 in the spine, P = 0.037 in hip) and milk-root vegetables pattern (P = 0.010 in hip) were associated with BMD of the spine and hip. The linear mixed model of follow-up data showed that lean mass, years since menopause, and age of menophania were the significant determinants of BMD of all sites. Moreover, lean mass was the best determinant of BMD (VIP = 1.936).

Conclusion

Lean mass, years since menopause, age of menophania and dietary patterns are the important determinants of BMD of the spine, hip, and the total body. Lean mass is the best determinant of BMD.

Comparison of body composition, nutritional status, functional status, and quality of life between osteoporotic and osteopenic postmenopausal women

BACKGROUND AND OBJECTIVE

Osteoporosis is a condition that affects body composition, physical activity, and psychological state. We aimed to examine the differences between osteoporotic and osteopenic postmenopausal women with respect to body composition, nutrition, functional status, and quality of life.

MATERIALS AND METHODS

A total of 102 osteopenic (Group 1) and 100 osteoporotic (Group 2) patients were enrolled in the study. Bone mineral density (BMD), fat tissue mass (FTM), lean tissue mass (LTM), and bone mineral content (BMC) were evaluated using dual-energy X-ray absorbtiometry. Nutritional status of the patients was assessed with the Mini Nutritional Assessment (MNA), functional status with the Nottingham Extended Activities of Daily Living (NEADL) scale, and quality of life with the assessment of health-related quality of life in osteoporosis (ECOS-16).

RESULTS

Group 2 had significantly lower FTM, LTM, and MNA scores than Group 1 (P<0.05). NEADL and ECOS-16 scores did not differ between the groups (P>0.05). A significant correlation was found between MNA and FTM, LTM, BMC, and BMD (P<0.05). Whereas the assessment of functional status showed a significant positive correlation with BMD and a significant negative correlation with age (P<0.05), no significant correlation was found between functional status and body composition (P>0.05).

CONCLUSIONS

We found lower FTM and LTM values and a poorer nutritional status in osteoporotic patients than in osteopenic ones. Nutritional status was correlated with body composition and BMD, and functional status was correlated with age and BMD.

Positive Association Between Adipose Tissue and Bone Stiffness

Obesity is often considered to have a protective effect against osteoporosis. On the other hand, several recent studies suggest that adipose tissue may have detrimental effects on bone quality. We therefore aimed to investigate the associations between body mass index (BMI), waist circumference (WC), visceral adipose tissue (VAT) or abdominal subcutaneous adipose tissue (SAT), and bone stiffness. The study involved 2685 German adults aged 20-79 years, who participated in either the second follow-up of the population-based Study of Health in Pomerania (SHIP-2) or the baseline examination of the SHIP-Trend cohort. VAT and abdominal SAT were quantified by magnetic resonance imaging. Bone stiffness was assessed by quantitative ultrasound (QUS) at the heel (Achilles InSight, GE Healthcare). The individual risk for osteoporotic fractures was determined based on the QUS-derived stiffness index and classified in low, medium, and high risk. Linear regression models, adjusted for sex, age, physical activity, smoking status, risky alcohol consumption, diabetes, and height (in models with VAT or abdominal SAT as exposure), revealed positive associations between BMI, WC, VAT or abdominal SAT, and the QUS variables broadband-ultrasound attenuation or stiffness index. Moreover, BMI was positively associated with speed of sound. Our study shows that all anthropometric measures including BMI and, WC as well as abdominal fat volume are positively associated with bone stiffness in the general population. As potential predictors of bone stiffness, VAT and abdominal SAT are not superior to easily available measures like BMI or WC.

Relative Importance of Lean and Fat Mass on Bone Mineral Density in Iranian Children and Adolescents

BACKGROUND

Body weight is made up of lean and fat mass and both are involved in growth and development. Impression of these two components in bone density accrual has been controversial.

OBJECTIVES

The aim of this study was to evaluate the relationship between fat and lean mass and bone density in Iranian children and adolescents.

PATIENTS AND METHODS

A cross-sectional study was performed on 472 subjects (235 girls, 237 boys) aged 9-18 years old in Fars Province. The participants' weight, height, waist circumference, stage of puberty, and level of physical activity were recorded. Bone Mineral Content (BMC), Bone Mineral Density (BMD), total body fat and lean mass were measured using dual-energy X-ray absorptiometry.

RESULTS

Results showed that 12.2% of boys and 12.3% of girls were overweight and 5.5% of boys and 4.7% of girls were obese. Obese individuals had greater total body BMD (0.96 ± 0.11) than normal-weight ones (0.86 ± 0.11) (P < 0.001). We found the greatest correlation between total body BMD and total body lean mass (R = 0.78. P < 0.001) and the least correlation with total body fat percentage (R = 0.03, P = 0.44). Total lean mass in more active boys was 38.1 ± 10.9 and in less active boys was 32.3 ± 11.0 (P < 0.001). The results of multiple regression analysis showed that age and total body lean mass were independent factors of BMD in growing children and adolescents.

CONCLUSIONS

These findings suggest that lean mass was the most important predictor of BMD in both genders. Physical activity appears to positively impact on lean mass and needs to be considered in physical education and health-enhancing programs in Iranian school children.

Associations between body mass index, lean and fat body mass and bone mineral density in middle-aged Australians: The Busselton Healthy Ageing Study

Low BMI is a risk factor for osteoporosis, but it is not clear if relationships between BMI, lean mass (LM), fat mass (FM) and BMD are consistent across different levels of BMI. We studied 1929 Caucasian participants (1014 females) aged 45-66years in the Busselton Healthy Ageing Study in Western Australia. Body composition and BMD of total body, lumbar spine, total hip and femoral neck were measured using DXA. From generalized additive models, the positive relationships between BMI and BMD were weaker at high BMI, particularly at the spine and in males. In the entire cohort, adjusting for relevant covariates, LM and FM were significant predictors of all BMD measures in both genders. In men, analysis by tertiles of BMI showed that LM and FM (in kg) were positively associated with BMD (in mg/cm(2)) in tertile 1 except for LM and spine BMD (LM β: 5.18-6.80, FM β: 3.38-9.24, all P<0.05), but not in the middle or upper tertiles (LM β: -3.12-3.07, FM β: -4.75-1.82, P>0.05). In women, LM was positively associated with BMD in each tertile of BMI, except for spine BMD in the upper tertile, with regression coefficients lower in the upper tertile (β: 5.16-9.95, 5.76-9.56 and 2.80-5.78, respectively, all P<0.05). FM was positively associated with total body, spine and total hip BMD in women in BMI tertile 1 (β: 2.86-6.68, P<0.05); these associations were weaker or absent in the middle and upper tertiles. In conclusion, in middle-aged adults the positive relationships between lean or fat mass with BMD among those with higher BMI are absent in males and weaker in females.

High fat diet promotes achievement of peak bone mass in young rats

The relationship between obesity and bone is complex. Epidemiological studies demonstrate positive as well as negative correlation between obesity and bone health. In the present study, we investigated the impact of high fat diet-induced obesity on peak bone mass. After 9 months of feeding young rats with high fat diet, we observed obesity phenotype in rats with increased body weight, fat mass, serum triglycerides and cholesterol. There were significant increases in serum total alkaline phosphatase, bone mineral density and bone mineral content. By micro-computed tomography (μ-CT), we observed a trend of better trabecular bones with respect to their microarchitecture and geometry. This indicated that high fat diet helps in achieving peak bone mass and microstructure at younger age. We subsequently shifted rats from high fat diet to normal diet for 6 months and evaluated bone/obesity parameters. It was observed that after shifting rats from high fat diet to normal diet, fat mass, serum triglycerides and cholesterol were significantly decreased. Interestingly, the gain in bone mineral density, bone mineral content and trabecular bone parameters by HFD was retained even after body weight and obesity were normalized. These results suggest that fat rich diet during growth could accelerate achievement of peak bone mass that is sustainable even after withdrawal of high fat diet.

Relationships of serum lipid profiles and bone mineral density in postmenopausal Chinese women

OBJECTIVES

Recent studies suggest that serum lipid profiles are related to bone mineral density (BMD). But data about this relationship on Chinese population are scarce. We investigated the relationships between serum lipid and BMD in postmenopausal Chinese women.

METHODS

A cross-sectional study was conducted in 790 Chinese postmenopausal women. BMDs were measured by dual X-ray absorptiometry. Serum lipid profiles were obtained after a 12-h fasting.

RESULTS

Women with serum high-density lipoprotein cholesterol (HDL-C) levels of at least 1·55 mmol/l had a greater prevalence of osteoporosis compared with women with lower HDL-C (≤1·54 mmol/l). After controlling for age, menopausal duration, body mass index, serum creatinine levels, outdoor activity, smoking and alcohol intake, high HDL-C levels were associated with osteoporosis (OR = 1·64, 95%CI 1·16-2·33, P < 0·01). BMD at femoral neck and total hip was significantly lower in the higher HDL-C class than the lower class (0·722 ± 0·118 vs 0·744 ± 0·120 g/cm(2) , P < 0·01; 0·800 ± 0·126 vs 0·824 ± 0·125 g/cm(2) , P < 0·01, respectively). No association was found between total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) with BMD.

CONCLUSIONS

In Chinese postmenopausal women, elevated levels of serum HDL-C had a greater probability of being osteoporosis than the lower HDL-C levels. Our analysis showed higher HDL-C level that is favourable for cardiovascular diseases should be regarded as a risk factor for osteoporosis.

Associations of fat mass and fat distribution with bone mineral density in Chinese obese population

The purpose of the study was to investigate the associations of fat mass (FM) and fat distribution with bone mineral density (BMD) in Chinese obese population. Three hundred and forty-seven Chinese obese females and 339 males aged 20-39 years were analyzed. Lean mass (LM), FM, percent body fat (%BF), android FM, gynoid FM, and total and regional BMD were measured using dual-energy X-ray absorptiometry. Fat distribution was assessed by android-to-gynoid FM ratio (AOI). As a result, increased central body fat had an inverse association with total and leg BMD in females but not in males. Increased FM and %BF were positively associated with arm, trunk, and pelvic BMD in Chinese obese females. Increased FM was positively associated with total, rib, and trunk BMD in Chinese obese males. The results remained almost unchanged after adjusting for LM, and LM was significantly positively associated with spine BMD in female group. FM was positively associated with trunk BMD in male group after adjusting for LM. AOI was inversely associated with total and leg BMD, and %BF was positively associated with arm, trunk, and pelvic BMD when replacing FM with %BF in female group. The results remained almost unchanged after adjusting for LM. There is no significant association in male group when replacing FM with %BF. In conclusion, our findings demonstrate that there are different associations of FM and fat distribution with BMD, and AOI has a negative association with BMD.