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

Associations of Body Mass Index and Percent Body Fat with Osteoporosis, Sarcopenia, and Osteosarcopenia: A Retrospective Study Based on Postmenopausal Women in China

Background/Objectives: Alterations in the body mass index (BMI) and percent body fat (PBF) have been considered to be related to aging-induced changes in bone and muscle. This study aimed to evaluate the associations of the BMI and PBF with osteoporosis, sarcopenia, and osteosarcopenia in postmenopausal women. Methods: A total of 342 participants who underwent musculoskeletal function assessments at the First Affiliated Hospital of Sun Yat-sen University between January 2015 and December 2022 were retrospectively screened. The diagnosis of osteoporosis was based on the WHO criteria, and sarcopenia was diagnosed according to the 2019 consensus of the Asian Working Group for Sarcopenia. Results: The BMI was positively correlated with the musculoskeletal function assessment parameters (bone mineral density, relative skeletal muscle index, and grip strength) and identified as an independent protective factor for sarcopenia alone (OR = 0.592, 95% CI: 0.455-0.769) or osteosarcopenia (OR = 0.411, 95% CI: 0.319-0.529), with a moderate diagnostic accuracy (area under the curve [AUC] = 0.682) for the former and a high diagnostic accuracy (AUC = 0.823) for the latter. However, the PBF was negatively correlated with the relative skeletal muscle index and identified as a risk factor for osteosarcopenia (OR = 1.404, 95% CI: 1.007-1.959), with a moderate diagnostic accuracy (AUC = 0.613). Conclusions: A higher BMI and lower PBF were associated with a lower prevalence of osteosarcopenia in postmenopausal women. Further research is required to elucidate the independent effects of the BMI and PBF on bone health.

Vertebral marrow fat fraction is associated with circulating RANKL in postmenopausal females

Objective

To investigate the relationship between circulating receptor activator of nuclear factor-kappa B ligand (RANKL) levels and marrow adipose tissue in postmenopausal females.

Methods

A total of 164 postmenopausal females were included in the study. Serum levels of osteoprotegerin (OPG) and RANKL were measured using ELISA kits. Body composition and bone mineral density (BMD) were assessed using dual-energy X-ray absorptiometry. Complex-based chemical shift imaging-based MRI was employed to evaluate the vertebral marrow proton density fat fraction (PDFF). A multivariate linear regression model was utilized to analyze the predictive effects of PDFF and BMD on circulating levels of OPG and RANKL.

Results

Simple regression analysis showed significant associations among the marrow PDFF, BMD at either site, serum RANKL, and the RANKL/OPG ratio. In multivariate linear regression models, marrow PDFF was found to have a positive correlation (β = 3.15, 95% CI 2.60 to 3.70) and BMD had negative correlations (β = -0.200, 95% CI -0.348 to -0.051 for vertebral BMD; β = -0.383, 95% CI -0.589 to -0.177 for total hip BMD; and β =-0.393, 95% CI -0.598 to -0.188 for femoral neck BMD, all p < 0.01) with circulating soluble RANKL levels after adjusting for age, body mass index, physical activity, total fat mass, android/gynoid ratio, and lean mass. Similar results were observed for the RANKL/OPG ratio. Additionally, multivariate linear regression analyses revealed that marrow PDFF was a significant independent contributor of circulating soluble RANKL (β = 1.34, 95% CI 1.10 to 1.58, p < 0.001) after further controlling for BMD. However, marrow PDFF or BMD had no associations with circulating levels of OPG after adjusting for all potential confounders mentioned above.

Conclusions

Vertebral marrow fat fraction is independently associated with circulating soluble RANKL levels in postmenopausal females.

T-score discordance between hip and lumbar spine: risk factors and clinical implications

Background

T-score discordance is common in osteoporosis diagnosis and leads to problems for clinicians formulating treatment plans.

Objectives

This study investigated the potential predictors of T-score discordance and compared fracture risk among individuals with varying T-score discordance status.

Design

This was a single-center cross-sectional study conducted at Wan Fang Hospital, Taipei City, between 1 February 2020 and 31 January 2022.

Methods

The present study enrolled patients aged ⩾50 years who received advanced bone health examination. Participants with a history of fracture surgery or underlying musculoskeletal diseases were excluded. Bioelectrical impedance analysis and dual-energy X-ray absorptiometry were used to determine the body composition and T-score, respectively. Discordance was defined as different T-score categories between the lumbar spine and hip. The impact of discordance on an individual's fracture risk was assessed using the Fracture Risk Assessment Tool (FRAX).

Results

This study enrolled 1402 participants (181 men and 1221 women). Of the 912 participants diagnosed with osteoporosis, 47 (5%) and 364 (40%) were categorized as having major and minor discordance, respectively. Multinomial logistic regression revealed that decreased walking speed was significantly correlated with major discordance but not osteoporosis in both the hip and lumbar spine (odds ratio of 0.25, p = 0.04). The adjusted FRAX scores for the major osteoporotic fracture risks of the major and minor discordance groups were approximately 14%, which was significantly lower than that of people having osteoporosis in both the hip and lumbar spine.

Conclusions

Walking speed exhibited the most significant correlation with major discordance in patients with osteoporosis. Although adjusted major fracture risks were similar between the major and minor discordance groups, further longitudinal studies are warranted to confirm this finding.

Registrations

This study was approved by the Ethics Committee of Taipei Medical University on 01/04/2022 (TMU-JIRB N202203088).

Associations of Fat Mass and Fat Distribution With Bone Mineral Density in Non-Obese Postmenopausal Chinese Women Over 60 Years Old

BACKGROUND

Bone mineral density (BMD) loss is a major complication of menopause, and this loss is closely associated with Fat mass (FM). The relationship between FM, fat distribution (FD), and BMD in postmenopausal women, however, remains incompletely understood. The present study was thus developed to explore these associations between body fat accumulation, FD, and BMD among non-obese postmenopausal women over the age of 60.

METHODS

This was a cross-sectional analysis of 357 healthy postmenopausal women between the ages of 60.2 and 86.7 years. Dual-energy X-ray absorptiometry (DXA) was utilized to measure total and regional BMD as well as fat-related parameters including total FM, android and gynoid fat, body fat percentage (BF%), and total lean mass (LM) for all subjects. The android-to-gynoid fat ratio (AOI) was used to assess FD. Pearson's correlation testing and multiple regression analyses were used to explore relationships among AOI, LM, FM, and BMD.

RESULTS

Both LM and FM were positively correlated with total and regional BMD in univariate analysis (all P < 0.01), whereas BMD was not significantly associated with AOI in any analyzed site other than the head. Multivariate linear regression models corrected for age, height, and years post-menopause, revealed a sustained independent positive relationship between FM and BMD (standard β range: 0.141 - 0.343, P < 0.01). The relationship between FM and BMD was unaffected by adjustment for LM (standard β range: 0.132 - 0.258, P < 0.01), whereas AOI had an adverse impact on BMD at most analyzed skeletal sites (total body, hip, femoral neck, arm, leg, and head) (standard β range: -0.093 to -0.232, P < 0.05). These findings were unaffected by using BF% in place of FM (standard β range: -0.100 to -0.232, P < 0.05).

CONCLUSIONS

In this cohort of non-obese postmenopausal women over the age of 60 from China, total FM was positively associated with BMD, while AOI was negatively correlated with BMD. As such, a combination of proper weight gain and the control of central obesity may benefit the overall bone health of women after menopause.

Fat distribution may predict intra- or extra-capsular hip fracture in geriatric patients after falling

INTRODUCTION

Hip fractures can be divided into intra-capsular and extra-capsular fracture based on fracture location; these two types of fracture have different pathogeneses, treatments and prognoses. Many factors influence the patterns of hip fractures, including the injury mechanism, areal bone mineral density and the geometry of the hip. However, the relationship between body composition and hip fracture pattern has not yet been discussed. In this investigation, an analysis of the body compositions of geriatric patients with hip fractures were conducted to identify differences between fat and muscle distributions between patients with intra- and extra-capsular hip fractures.

MATERIAL AND METHODS

From December 2017 to February 2019, 139 patients with a hip fracture were prospectively enrolled in this study. The groups of patients that were diagnosed as having intra- and extra-capsular hip fractures were compared in terms of patient demographics, pre-operative laboratory data, bone mineral density (BMD) and body composition including muscle and fat distributions obtained using dual-energy X-ray absorptiometry (DXA) .

RESULTS

Eighty-six and 53 patients were diagnosed with intra-capsular and extra-capsular hip fractures, respectively. A significantly higher serum glucose level, a lower hemoglobin level, a lower T-score level in the proximal femur region, a lower T-score of all parts of interest, and a lower percentage fat content on the region of bilateral proximal hips (gynoid region) and in the lower limb region, were observed in patients with an extra-capsular hip fracture than in those with an intra-capsular hip fracture. However, with all confounding factors controlled for, only the T-score at the proximal femur, percentage fat content in the region of bilateral proximal hips and the ratio of android fat content to gynoid fat content (A/G ratio) are the most relevant factors in predicting the patterns of hip fracture in geriatric patients after falling.

CONCLUSION

This work demonstrates that lower fat content in the region of bilateral proximal hips and a lower BMD on the proximal femur may predict greater vulnerability of geriatric patients to extra-capsular rather than intra-capsular hip fracture after a falling accident.

Association between high levels of gynoid fat and the increase of bone mineral density in women

Introduction: In women, bone mineral density (BMD) is related to age, estrogenic action, and appendicular skeletal muscle mass (ASMM). The gynoid fat distribution is linked to estrogenic action.Objective: This study aimed to assess whether an increase of gynoid fat is associated with high BMD independent of age and ASMM.Methods: An observational study was performed in women aged between 20 and 79 years. Fat mass, ASMM, and BMD were measured with dual-energy X-ray absorptiometry. The binned scatterplots and multivariate linear regression models were used to study the relationship between hip BMD and age, height, android fat, gynoid fat, and ASMM.Results: Of 673 women invited, 596 accepted to participate. Their mean age was 55.4 ± 12.8 years, weight 63.4 ± 9.4 kg, height 1.61 ± 0.06 m, body mass index 24.54 ± 3.59 kg/m², average hip BMD 0.914 ± 0.122 g/cm², android fat 2.12 ± 0.83 kg, gynoid fat 4.54 ± 1.07 kg, and ASMM 15.15 ± 1.97 kg. The final regression model included age (linear coefficient -0.004; 95% confidence interval [CI]: -0.005 to -0.003; p < 0.001), ASMM (linear coefficient 0.013; 95% CI: 0.009 to 0.018; p < 0.001), and gynoid fat (linear coefficient 0.013; 95% CI: 0.005 to 0.022; p < 0.002).Conclusion: Gynoid fat is associated with BMD in the hip independently of age and ASMM.

Contribution of Android and Gynoid Adiposity to Bone Mineral Density in Healthy Postmenopausal Thai Women

Dual-energy X-ray absorptiometry (DXA) is one of the major tools for assessing the whole body and regional body composition and body adiposity. Various body composition parameters including android fat mass (AFM), gynoid fat mass (GFM), and android-to-gynoid fat ratio (AG fat ratio) obtained from whole body DXA can be used as a reliable surrogate marker for regional body composition analysis. This study aimed to explore the contribution of android and gynoid adiposity to bone mineral density (BMD) in healthy postmenopausal Thai women. This cross-sectional study enrolled 1448 healthy Thai women, ages 40-90 without medication history or known disease affecting the BMD. Lumbar spine (LS), total femur, and femoral neck BMDs, AFM, GFM, and AG fat ratio were measured by DXA. To evaluate the contribution of android and gynoid adiposity with various measures of BMDs, univariable and multivariable linear regression analyses were used to estimate the regression coefficients. AFM, GFM, and AG fat ratio had a significant positive association with BMD of all measured sites (p < 0.001) in the univariate analysis. The strongest association was found between AG fat ratio and LS BMD (β = 0.156, p ≤ 0.001). In multivariate linear regression analysis, the results continued to show a positive association between AFM and GFM at all skeletal sites after adjusting for age, height, and total body lean mass. Relationship between AG fat ratio and BMD was found only in LS region. GFM had a strongest positive effect with BMD at the LS, total femur, and femoral neck regions. Higher android and gynoid adiposity was associated with higher BMD. GFM rather than AFM shows the strongest positive association with BMDs in postmenopausal Thai women.

Baseline bone health status in multi-ethnic South African postmenopausal breast cancer patients at initiation of aromatase inhibitor therapy: A descriptive study

Introduction

Osteoporosis (OP) risk factor assessment and bone mineral density (BMD) testing are frequently omitted at baseline in aromatase inhibitor (AI) studies, which may lead to misinterpretation of AI associated bone loss. The present study describes bone health of South African postmenopausal women of predominantly Mixed Ancestry, prior to AI treatment.

Methods

This descriptive baseline study, nested in a prospective AI cohort study, included postmenopausal women with endocrine sensitive breast cancer, aged 50 to 80 years. A baseline questionnaire documented demographic-, medical-, lifestyle- and fracture history. Body weight was assessed clinically, and body composition and BMD measured via dual energy absorptiometry (DXA). Data was analysed in STATA 14 using descriptive and inferential statistics.

Results

101 participants were recruited, with a mean age of 61±7 years. Nearly a third (n = 32) of women at baseline fulfilled global criteria for bone protection (BMD T-score ≥-2SD (n = 18); BMD T-score -1.5SD to < -2SD with risk factors (n = 14). Lower body weight, body mass index (BMI), fat mass index and lean mass index were significantly associated with the participants with a BMD measurement in keeping with a diagnosis of OP (p <0.001). Low vitamin D was present in 93% of the cohort tested (n = 95), whilst deficient vitamin D status (<20ng/ml) was documented in 52 women (55%).

Conclusions

In this study, a third of postmenopausal women considered for AI therapy fulfilled international criteria for bone protective pharmacological intervention. This emphasizes the need for clinical risk and BMD assessment in postmenopausal breast cancer patients at baseline. Body composition and bone health associations highlight bone fragility associated with lower body weight.

Modifications in the spectrum of bone mass predictive factors with menopausal status

PURPOSE

Fat mass (FM) is a source of adipocytokines, with both positive and negative bone consequences. We aimed to investigate the role of body composition and adipokines as predictive factors for bone mass in women.

METHODOLOGY

This cross-sectional study included 93 women (38 premenopausal and 55 postmenopausal). Bone mineral density (BMD) and body composition were assessed by dual-energy X-ray absorptiometry. Serum levels of leptin, adiponectin, resistin, and also of the phosphocalcic markers parathormone and vitamin D were measured.

RESULTS

Only lean mass (LM) was an independent predictor of BMD in premenopausal women (r² = 0.381, p < 0.001 for femoral neck BMD, r² = 0.2, p < 0.01 for whole-body BMD) in both unadjusted and age-adjusted models. The effect of total FM upon BMD became nonsignificant when LM was added to the models assessed. In postmenopausal women, although LM, trunk-to-leg fat ratio, and resistin were initially associated with BMD in unadjusted models, only the trunk-to-leg fat ratio independently predicted BMD at various sites (r² = 0.171, p < 0.01 for lumbar BMD, r² = 0.078, p < 0.05 for radius BMD, r² = 0.094, p < 0.05 for whole-body BMD) after adjusting for age.

CONCLUSIONS

While in premenopausal women the effect of LM upon bone is prevalent, after menopause, the fat distribution reflected by trunk-to-leg fat ratio is a major determinant of bone mass at different sites. Our study also stresses that the relationship between total FM and BMD is not mediated by adipokines in women irrespective of menopausal status and body composition, but it is largely mediated by LM only in young premenopausal women.

Association between obesity and femoral neck strength according to age, sex, and fat distribution

Indicators of total and abdominal obesity were negatively associated with femoral neck strength indices. There are age-, sex-, and fat distribution-specific differences in the magnitude of these associations. These suggested that indicators of obesity with different magnitude according to age, sex, and fat distribution associated with poor bone health.

INTRODUCTION

Fat regulates bone metabolism, but the associations of total and abdominal obesity with bone health are inconsistent. We investigated the association between indicators of obesity and composite indices of femoral neck (FN) strength reflecting the risk of hip fracture.

METHODS

This population-based cross-sectional study examined data from the Korea National Health and Nutrition Examination Surveys. Participants were divided into groups according to age (25-49/≥50 years) and sex. We examined total fat mass (TFM) and percentage fat mass (pFM) as indicators of total obesity and truncal fat mass (TrFM) as an indicator of abdominal obesity. We calculated the composite indices of FN strength and anthropometric clinical indicators of abdominal obesity.

RESULTS

TFM, pFM, and TrFM were negatively associated with the composite indices, irrespective of age and sex (P < 0.001-0.005). Most anthropometric clinical indicators of abdominal obesity showed negative associations with the composite indices regardless of age and sex (P < 0.001-0.048), except for women aged 25-49 years. In men, magnitudes of the negative contributions of TFM to the composite indices were significantly stronger at age 25-49 years than at age ≥50 years. Magnitudes of negative associations of TFM with the composite indices were greater in men than in women. TrFM had a more detrimental effect than TFM on FN strength in men aged 25-49 years and in women of both ages.

CONCLUSION

Indicators of total and abdominal obesity negatively associated with FN strength, and magnitudes of their effects on bone health differed according to age, sex, and fat distribution.

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.

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.