Gender-Specific Body Composition Relationships between Adipose Tissue Distribution and Peak Bone Mineral Density in Young Chinese Adults

Linear and non-linear relationships between body fat mass distribution and bone mineral density in adults: The NHANES, 2011-2018

OBJECTIVE

The relationship between body fat mass and bone mineral density (BMD) remains controversial. This research aimed to explore the linear or non-linear relationship between body fat mass and BMD among adults in the United States.

METHODS

This cross-sectional study identified adults aged 18 years or older in the National Health and Nutrition Examination Survey from 2011 to 2018. After adjusting for covariates, linear relationships between body fat mass and BMD in different genders were tested by generalized linear models, and potential non-linear relationships were explored by generalized additive models and piecewise linear regression models.

RESULTS

The research included 4691 (57.9% of the total sample) males and 3417 (42.1% the of total sample) females. In both males and females, we found a negative association between android or total body fat mass and lumbar spine BMD and a positive association between appendicular, android, gynoid, or total body fat mass and whole body BMD (all P < 0.05). The relationships between body fat mass in all regions and lumbar spine BMD were U-shaped in males and inverted U-shaped in females (all Pnon-linear < 0.05). Inverted U-shaped relationships existed between body fat mass in all regions and whole body BMD in females (all Pnon-linear < 0.05).

CONCLUSIONS

Body fat mass was negatively and linearly associated with lumbar spine BMD, but positively associated with whole body BMD. Body fat mass had a U-shaped relationship with lumbar spine BMD in males and an inverted U-shaped association with lumbar spine and whole body BMD in females.

Bone health and body composition in transgender adults before gender-affirming hormonal therapy: data from the COMET study

PURPOSE

Preliminary data suggested that bone mineral density (BMD) in transgender adults before initiating gender-affirming hormone therapy (GAHT) is lower when compared to cisgender controls. In this study, we analyzed bone metabolism in a sample of transgender adults before GAHT, and its possible correlation with biochemical profile, body composition and lifestyle habits (i.e., tobacco smoke and physical activity).

METHODS

Medical data, smoking habits, phospho-calcic and hormonal blood tests and densitometric parameters were collected in a sample of 125 transgender adults, 78 Assigned Females At Birth (AFAB) and 47 Assigned Males At Birth (AMAB) before GAHT initiation and 146 cisgender controls (57 females and 89 males) matched by sex assigned at birth and age. 55 transgender and 46 cisgender controls also underwent a complete body composition evaluation and assessment of physical activity using the International Physical Activity Questionnaire (IPAQ).

RESULTS

14.3% of transgender and 6.2% of cisgender sample, respectively, had z-score values < -2 (p = 0.04). We observed only lower vitamin D values in transgender sample regarding biochemical/hormonal profile. AFAB transgender people had more total fat mass, while AMAB transgender individuals had reduced total lean mass as compared to cisgender people (53.94 ± 7.74 vs 58.38 ± 6.91, p < 0.05). AFAB transgender adults were more likely to be active smokers and tend to spend more time indoor. Fat Mass Index (FMI) was correlated with lumbar and femur BMD both in transgender individuals, while no correlations were found between lean mass parameters and BMD in AMAB transgender people.

CONCLUSIONS

Body composition and lifestyle factors could contribute to low BMD in transgender adults before GAHT.

Peak Bone Mass Formation: Modern View of the Problem

Peak bone mass is the amount of bone tissue that is formed when a stable skeletal state is achieved at a young age. To date, there are no established peak bone mass standards nor clear data on the age at which peak bone mass occurs. At the same time, the level of peak bone mass at a young age is an important predictor of the onset of primary osteoporosis. The purpose of this review is to analyze the results of studies of levels of peak bone mass in general, the age of its onset, as well as factors influencing its formation. Factors such as hormonal levels, body composition, physical activity, nutrition, heredity, smoking, lifestyle, prenatal predictors, intestinal microbiota, and vitamin and micronutrient status were considered, and a comprehensive scheme of the influence of these factors on the level of peak bone mass was created. Determining the standards and timing of the formation of peak bone mass, and the factors affecting it, will help in the development of measures to prevent its shortage and the consequent prevention of osteoporosis and concomitant diseases.

Body Fat Distribution and Female Infertility: a Cross-Sectional Analysis Among US Women

At present, the effect of body fat distribution on female reproductive health is still inconclusive. The purpose of our study was to analyze the correlation between female infertility rates and the fat mass portion of the android region to the gynoid region (the A/G ratio) among US women of reproductive age. Female infertility is defined as a failure to get pregnant after 12 months of unprotected sexual activity. A total of 3434 women of reproductive age were included in this study as part of the 2013-2018 National Health and Nutrition Examination Survey (NHANES). The A/G ratio was used to assess the body fat distribution of participants. Based on the comprehensive study design and sample weights, it was determined that the A/G ratio was associated with female infertility primarily through logistic regression analyses. After adjusting for potential confounders, the multivariate regression analysis indicated an increase in the A/G ratio was correlated with an increase in the prevalence of female infertility (OR = 4.374, 95% CI:1.809-10.575). Subgroup analyses showed an increased prevalence of infertility in non-Hispanic Whites (P = 0.012), non-diabetic individuals (P = 0.008), individuals under 35 years old (P = 0.002), and individuals with secondary infertility (P = 0.01). The trend tests and smooth curve fitting illustrate a linear trend between the A/G ratio and female infertility. Future researches are warranted to confirm the causal relationship between body fat distribution and female infertility, which may provide an insight into future prevention and treatment of female infertility.

The association of body composition and fat distribution with dysmobility syndrome in community-dwelling older adults: Bushehr Elderly Health (BEH) program

BACKGROUND AND OBJECTIVE

Dysmobility Syndrome (DS) is characterized as an accumulation of clinical risk factors for functional disability, such as osteoporosis, sarcopenia, and obesity. Neurological disorders that affect the motor and sensory systems can also contribute to the condition, resulting in gait and muscle strength disturbances, as well as a history of falls and fractures. The study aimed to determine the association between fat distribution in different body areas and the odds of older adults developing DS, as there is still uncertainty about the accumulation of fat in which area is most closely linked to the condition.

METHODS

This cross-sectional study was conducted according to the data from the second phase of the Bushehr Elderly Health Cohort (BEH). Dysmobility Syndrome was defined based on the co-occurrence of at least three outcomes of its criteria. Body composition was measured using dual-energy X-ray absorptiometry (DXA) and anthropometric studies. For evaluating the relationship, multivariate logistic regression and adjusted univariate linear regression were used.

RESULTS

Of 2,359 who were recruited in the study, 1,277 participants (54.13%) had DS. According to the final logistic regression model in the limb region, FM and FM to FFM ratios were significantly associated with DS [OR (95%CI) = 1.04 (1.02 to 1.05), and 3.42 (1.95 to 5.99), respectively]. Also, In the trunk region, the FM and FM to FFM ratio were significantly related to the odds of DS, although this relationship was weaker than in the limbs region [OR (95%CI) = 1.02 (1.00 to 1.03), and 2.45 (1.36 to 4.39), respectively].

CONCLUSION

Our findings indicate that a higher regional and whole-body amount of fat mass rather than fat-free mass is closely linked to an increased risk of DS, particularly in the elderly population. Notably, higher fat mass in the limbs (especially in the legs) is associated with greater odds of DS, while a higher android-to-gynoid fat mass ratio is associated with lower DS risk. Screening fat mass distribution in older individuals can be a valuable strategy for promptly diagnosing DS, implementing interventions to prevent disabilities, and improving their quality of life.

Longitudinal relationship between body fat percentage and risk of type 2 diabetes in Chinese adults: Evidence from the China Health and Nutrition Survey

Objective

Body fat percentage (BF%) might be an alternative index of obesity which is the major risk factor for developing type 2 diabetes (T2D). We aim to longitudinally evaluated the relationship between BF% and risk of T2D.

Methods

A sample of 5,595 adults aged 18-65 who participated in two waves of China Health and Nutrition Survey (CHNS 2015 and 2018) was analyzed. Two level mixed-effects modified Poisson regression with robust estimation of variance stratified by sex was used to evaluate the risk ratios (RRs) for T2D according to quintiles of BF%, and the curves of receiver operating characteristic (ROC) were plotted to identify the optimal total and trunk BF% cut-off points for predicting an increased T2D risk.

Results

In males, compared with subjects in the first quintile of total BF%, those in the third (RR = 2.03, 95% CI 1.09-3.79), fourth (RR = 2.56, 95%CI 1.46-4.48), and fifth (RR = 2.16, 95%CI 1.22-3.82) quintile had higher risk of T2D after adjusting for all potential confounders (p-trend < 0.001). For females, the RR (95% CI) was 1.92 (1.14, 3.24) in the fifth quintile (p-trend = 0.014). Males and females with a trunk BF% >25.5 and 34.4% (≥ quintile 4), respectively, were at significantly increased risk of T2D (p-trend = 0.001). Besides, the optimal cut-off values of total and trunk BF% were 21.9 and 25.2% for males, and 36.7 and 30.3% for females, respectively.

Conclusions

The incident risk of T2D significantly increased over specific level of total and trunk BF% in both Chinese males and females, and the optimal BF% cut-off values were valuable for clinical application of BF% based on sex difference, which may be a cost-effective implementation for prevention and treatment of T2D in China.

The associations between body composition and vital capacity index of medical students in Shenyang of China: a cross-sectional survey

Objectives

This study aimed to examine the associations between body composition and vital capacity index (VCI) among medical students of Shenyang, China.

Study design

The design of this study is a cross-sectional study.

Methods

Participants were 2063 individuals (17–25 years) from a medical college in Shenyang, who participated in this survey from April to May 2017. Height, weight, fat mass (FM), fat free mass (FFM), protein mass (PM), total body water (TBW), mineral mass (MM), vital capacity were measured, then BMI and VCI were calculated. Stepwise multiple linear regression analysis was used to evaluate the effect of body composition on VCI of participants in different genders. In addition, subgroup analysis was carried out according to BMI levels.

Results

Male students showed significantly higher height, weight, BMI, FFM, PM, TBW, MM, VC, and VCI, but lower FM in comparison with female students. Stepwise multiple linear regression analysis showed that in both sexes FM was negatively correlated with VCI which represents pulmonary function (r < 0; P < 0.001). After dividing the whole participants by BMI, further correlation analysis showed FM was positively correlated with VCI only for male subgroups with BMI < 18.5 (r > 0; P = 0.050).

Conclusion

Overall, FM is highly negatively correlated with the VCI of Chinese medical students of both genders. However, there was a positive correlation between FM and VCI among low-weight male students.

Sex Differences in Bone Health Among Indian Older Adults with Obesity, Sarcopenia, and Sarcopenic Obesity

Age-related changes in fat and lean mass contribute to bone health, but these associations may be influenced by sex and ethnicity. This study investigated sex-specific associations of obesity and sarcopenia with bone mineral density (BMD) and bone mineral apparent density (BMAD) among Indian older adults. 1057 adults aged ≥ 50 years were included. Dual-energy X-ray absorptiometry (DXA) measured BMD at the hip, spine and whole-body, and BMAD was calculated as BMD/√bone area. Obesity was defined by body fat percentage (cut points; > 25% for men and > 35% for women), and sarcopenia was defined using the revised Asian Working Group for Sarcopenia classification with low hand grip strength (< 28 kg for men and < 18 kg for women) and appendicular lean mass index (< 7.0 kg/m² for men and < 5.4 kg/m² for women). Participants were classified into four groups: controls (no obesity or sarcopenia), obesity, sarcopenia, or sarcopenic obesity. Linear regression (β-coefficients and 95%CI) analyses were performed with adjustments for age, smoking status, protein intake, and socioeconomic status. Prevalence of sarcopenia (37%) and sarcopenic obesity (6%) were higher in men than women (17% and 4%, respectively). Compared with controls, men with obesity had lower whole-body BMD and BMAD, but women with obesity had higher hip and spine BMD and BMAD (all p < 0.05). Men, but not women, with sarcopenic obesity, had lower hip and whole-body BMD and BMAD (all p < 0.05) than controls. Men with sarcopenia had lower BMD and BMAD at the hip only, whereas women had lower BMD at all three sites and had lower BMAD at the hip and spine (all p < 0.05), compared with controls. Obesity, sarcopenia, and sarcopenic obesity have sex-specific associations with BMD and BMAD in Indian older adults. With the aging population in India, it is important to understand how body composition contributes to poor bone health among older adults.

Relationship between oseteoporosis with fatty infiltration of paraspinal muscles based on QCT examination

INTRODUCTION

To investigate the correlation between paraspinal muscles features and osteoporosis in lumbar spine.

MATERIALS AND METHODS

A total of 367 subjects who underwent quantitative computed tomography (QCT) examination were enrolled in this study. QCT pro workstation was used to obtain the mean bone mineral density (BMD) of the lower lumbar spine. Fat fraction (FF) and cross-section area (CSA) of the paraspinal muscles at the corresponding levels were measured. All participants were divided into normal, osteopenia, and osteoporosis groups. One-way ANOVA and independent samples t tests were performed to compare differences between groups. Pearson and Spearman correlation coefficients and partial correlation analysis after controlling for confounding factors were used to analyze the correlation between BMD and paraspinal muscles measurements.

RESULTS

Among the 367 participants included, 116 were in the normal group, 130 in the osteopenia group and 121 in the osteoporosis group. There were significant differences among the three groups for the mean and multifidus FF. BMD showed negative correlations with the FF of the paraspinal muscles. Multifidus and mean FF showed the best correlation (r = - 0.654, - 0.777). There were also significant differences in the mean and multifidus FF between different age groups, while after controlling for confounding factors, there was no correlation between age and FF of the paraspinal muscles.

CONCLUSION

This preliminary study demonstrated the association of BMD with fatty infiltration of paraspinal muscles. Different muscles might have specific effects in different sex and age groups.

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.

Association of Body Compositions and Bone Mineral Density in Chinese Children and Adolescents: Compositional Data Analysis

The purpose of this study was to investigate the relationship between body compositions and bone mineral density (BMD) and the effect of composition substitution among Chinese children and adolescents without the influence of multicollinearity. A dual-energy X-ray absorptiometry scan was used to determine the amount of truncal fat (TF), nontruncal fat (NTF), fat-free mass (FFM), and BMD. The compositional data analysis and the compositional proportional substitution analysis were conducted to determine the effect of each part of body compositions on BMD and its substitution effects. Four hundred sixty-six (466) (boys: 51.9%) participants completed this cross-sectional study. For girls, in the overweight group, the relationship between TF and the BMD was positive (β = 2.943e - 01, p = 0.006) while the NTF showed the opposite trend (β = -2.358e - 01, p = 0.009). When 4% NTF or FFM was substituted by TF, the BMD increased by about 0.1 and 0.05 units (p < 0.05), respectively. For boys, the association between FFM and BMD was statistically positive (β = 4.091e - 02, p = 0.0001). There was a positive correlation between TF and BMD (β = 7.963e - 02, p = 0.036). But with the increase of BMI, this correlation shifted in the opposite direction. In conclusion, compared to TF and NTF, FFM had a better protective effect on BMD, especially for boys. The risk of NTF accumulation on BMD was greater than that of TF accumulation. Compared with girls, boys were more sensitive to the amount of TF.

The Gender-Specific Relationship between Nutritional Status, Physical Activity and Functional Mobility in Irish Community-Dwelling Older Adults

Research suggests that both nutrition and physical activity can protect mobility in older adults, but it is yet to be determined whether these relationships are affected by gender. Thus, we investigated the gender-specific relationship between nutritional status, physical activity level and functional mobility in Irish older adults. A cross-sectional study was undertaken in 176 community-dwelling older adults (73.6 ± 6.61 years) living in Cork, Ireland. Nutritional status was measured using the Mini Nutritional Assessment-Short Form (MNA-SF) and physical activity was assessed via the Physical Activity Scale for the Elderly (PASE). Functional mobility was measured using the Timed Up and Go (TUG) test. The gender-stratified relationship between variables was assessed using Pearson's correlations and multiple linear regression. Partial correlations (p < 0.05) were observed for TUG with PASE score in both genders, and with MNA-SF score in females, only. Multiple regression showed that physical activity was a predictor of TUG in both genders (β = 0.257 for males, β = 0.209 for females, p < 0.05), while nutritional status was a predictor of TUG in females, only (β = -0.168, p = 0.030). Our results suggest that physical activity is associated with functional mobility in both genders, while the relationship between nutritional status and mobility may be specific to older females. These findings may be of interest for the design of functional preservation strategies.