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Purpose: The aims of the study were to develop sex- and age-specific percentiles for lean mass index (LMI), appendicular LMI (aLMI), fat mass index (FMI), and body fat distribution indices in Chinese adults using dual-energy X-ray absorptiometry (DXA), and to compare those indices with those of other ethnicities using the US NHANES data. Methods: Whole-body and regional lean mass and fat mass (FM) were measured using DXA in 5688 healthy males ( n = 1693) and females ( n = 3995) aged 20-90 years. Body fat distribution indices were expressed as % fat trunk/% fat legs, trunk/appendicular FM ratio (FMR), and android/gynoid FMR. Percentile curves of LMI, aLMI, FMI, and body fat distribution indices were obtained by the Lambda-Mu-Sigma method. Results: The aLMI and LMI were negatively associated with age, decreasing from the fifth decade for males, but were not associated with age in females. Females had more total FM than males, whereas males had greater central adiposity (% fat trunk/% fat legs ratio, trunk/appendicular FMR, and android/gynoid FMR) than females. Moreover, FMI and body fat distribution indices consistently increased with age in both sexes, especially in women. In comparison with white, black, and Mexican populations in the USA, Chinese adults had lower total FM, but had greater central adiposity (% fat trunk/% fat legs ratio and trunk/appendicular FMR). Additionally, older white and Mexican populations showed greater decreases for aLMI and LMI than their Chinese counterparts. Conclusions: We present the sex- and age-specific percentiles for aLMI, LMI, FMI, and body fat distribution indices by DXA in Chinese adults, which may refine the individual assessment of the nutritional status of Chinese adults. [ABSTRACT FROM AUTHOR]

Background: Being overweight or obese has become a serious public health concern, and accurate assessment of body composition is particularly important. More precise indicators of body fat composition include visceral adipose tissue (VAT) mass and total body fat percentage (TBF%). Study objectives included examining the relationships between abdominal fat mass, measured by quantitative computed tomography (QCT), and the whole-body and regional fat masses, measured by dual energy X-ray absorptiometry (DXA), as well as to derive equations for the prediction of TBF% using data obtained from multiple QCT slices., Methods: Whole-body and regional fat percentage were quantified using DXA in Chinese males (n = 68) and females (n = 71) between the ages of 24 and 88. All the participants also underwent abdominal QCT measurement, and their VAT mass and visceral fat volume (VFV) were assessed using QCT and DXA, respectively., Results: DXA-derived TBF% closely correlated with QCT abdominal fat percentage (r = 0.89-0.93 in men and 0.76-0.88 in women). Stepwise regression showed that single-slice QCT data were the best predictors of DXA-derived TBF%, DXA android fat percentage and DXA gynoid fat percentage. Cross-validation analysis showed that TBF% and android fat percentage could be accurately predicted using QCT data in both sexes. There were close correlations between QCT-derived and DXA-derived VFV (r = 0.97 in men and 0.93 in women)., Conclusion: Clinicians can assess the TBF% and android and gynoid fat percentages of Chinese women and men by analysing existing abdominal CT-derived data using the QCT technique., (© 2024. The Author(s).)

Objectives: This study was an attempt to investigate the variation trend of body composition with ageing and explore the association between regional body composition and bone mineral density (BMD)., Design: Cross-sectional study., Setting and Participants: A total of 5749 healthy adults aged 20-95 years was recruited from 2004 to 2017., Primary Outcome Measures: Whole-body lean mass (LM), fat mass (FM), android FM, gynoid FM, appendicular lean mass (ALM) and BMD in the lumbar spine, femoral neck and total hip were obtained by dual-energy X-ray absorptiometry (DXA). The android/gynoid fat mass ratio (A/G FMR) based on DXA scan was calculated as an indicator of adipose distribution. Pearson correlation and multiple linear regression analyses were used to determine the associations between body composition, adipose distribution, and BMD of each skeletal site., Results: Whole-body FM, percentage of whole-body FM, Android FM and A/G FMR consistently increased with age in both genders, especially in women, and ALM began to decrease in the fifth decade for both men and women. In multivariable linear regression models with age, body mass index, A/G FMR and ALM as predictor variables, ALM was associated with the most BMD variance of all skeletal sites in men (standard β ranged from 0.207 to 0.405, p<0.001), although not the largest but still a positive predictor of BMD in women (standard β ranged from 0.074 to 0.186, p<0.05). A/G FMR was an inverse predictor of BMD at all skeletal sites for women (standard β ranged from -249 to -0.052, p<0.01) but not in men., Conclusions: In this large cohort of Chinese adults, ALM had a strong positive association with BMD in both genders. A/G FMR as an indicator of central adipose accumulation was inversely associated with BMD in women but not in men., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: To develop predictive equations of lean body mass (LBM) suitable for healthy southern Chinese adults with a large sample. LBM measured by dual-energy X-ray absorptiometry (DXA) are considered as the standard ones., Methods: Retrospective analysis was conducted on the consecutive people who did total body measurement with DXA from July 2005 to October 2015. People with diseases that might affect LBM were excluded and overall 12,194 subjects were included in this study. Information about the 10,683 subjects (2,987 males and 7,696 females) from July 2005 to November 2014 was used to establish equations. These subjects were grouped by sex and then subdivided according to their body mass index (BMI). The female group was divided into another two subgroups: the premenopausal and postmenopausal subgroups. Equations were developed through stepwise multilinear regression analysis of height, weight, age, and BMI. Information about the 1,511 subjects (395 males and 1116 females) from December 2014 to October 2015 was used to verify the established equations., Results: BMI, height, weight, and age were introduced into the equations as independent variables in the male group, while age was proved to have no influence on LBM in the female group. Regrouping according to BMI or menopause did not increase the predictive ability of equations. Good agreement between LBM evaluated by equation (LBM&#95;PE) and LBM measured by DXA (LBM&#95;DXA) was observed in both the male and female groups., Conclusion: Predictive equations of LBM suitable for healthy southern Chinese adults are established with a large sample. BMI was related to LBM content; however, there is no need for further group based on BMI or menopause while developing LBM questions.

Background: This study aimed to establish gender-related differences and the percentile curves for total body fat mass percentage (Total FM%), trunk/appendicular fat mass ratio (TrAppFMR), and fat mass ratio as % fat trunk/% fat lower limb (TrLLFMR) in Chinese children and adolescents using dual-energy X-ray absorptiometry (DXA)., Methods: Children (n = 1541; 764 girls) and adolescents aged 5 to 19 years were recruited from southern China. Total FM% and regional FM were measured by DXA. TrAppFMR values were calculated as trunk FM divided by appendicular FM, and TrLLFMR values were calculated as the ratio between the percentage of trunk FM and the percentage of lower limb FM., Results: Total FM% peaks for boys were at approximately age 11 years and continued to increase for girls throughout adolescence. Median Total FM% at the age of 19 years was 15.53% and 28.06% for boys and girls, respectively. Median TrAppFMR and TrLLFMR increases were 61% and 81% from 5 to 19 years of age in boys compared with those in girls, 31% and 54%. The curves for median TrAppFMR and TrLLFMR in girls were relatively flat, with TrAppFMR and TrLLFMR remaining near 1.0 after 16 years of age, whereas in boys, median TrAppFMR and TrLLFMR increased with age until approximately 19 years., Conclusions: Gender differences in the patterns of proportion and distribution of body fat were found. We present sex-specific percentile curves for Total FM%-age, TrAppFMR-age, and TrLLFMR-age relationships in this population.

We investigated age-related changes in estimated bone strength and cross-sectional structure of the femoral neck (FN) in mainland Chinese men and women (according to age and sex) using dual-energy X-ray absorptiometry (DXA). A total of 3855 healthy adults (2713 women, 1142 men; ages 25-91years) were analyzed by FN bone mineral density (BMD) assessment and hip structural/strength analysis (HSA), including cross-sectional moment of inertia (CSMI), cross-sectional area (CSA), section modulus (Z), periosteal diameter (PD), endocortical diameter (ED), and cortical thickness (CT) using DXA. HSA differences between age and sex groups were adjusted for body weight, height and FN BMD. Trends according to age were estimated by linear regression analysis. There was no inverse correlation between HSA parameters and age in young adults. Some HSA parameters (CSMI, CSA, Z, CT) decreased significantly with age, whereas PD and ED increased significantly. Older adults had less estimated bone strength and CT and higher PD and ED (p<0.05) than young adults. Men had greater increases in PD and ED than women across all ages. FN strength decreases with age in both sexes, caused by FN cross-sectional structural deterioration. Indirect comparison of our data with those from other populations showed less age-related FN periosteal apposition in Chinese than Caucasian men, but similar amounts in women. This may partly explain different male/female hip fracture rates among ethnic groups. Chinese men have more structural disadvantages regarding FN geometry during aging than Caucasian men, possibly conferring added susceptibility to hip fracture., (Copyright © 2015 Elsevier Inc. All rights reserved.)