BACKGROUND: The fat-to-muscle mass ratio (FMR), integrating the antagonistic effects of fat and muscle mass, has been suggested as a valuable indicator to assess cardiometabolic health independent of overall adiposity. However, the specific associations of total and regional FMR with cardiometabolic risk are poorly understood. We aimed to examine sex-specific associations of total and regional FMR with single and clustered cardiometabolic risk factors (CRFs).
METHODS: 13,505 participants aged 20 years and above were included in the cross-sectional study. Fat mass and muscle mass were assessed using a bioelectrical impedance analysis device. FMR was estimated as fat mass divided by muscle mass in corresponding body parts (whole body, arm, leg, and trunk). Clustered CRFs was defined as the presence of two or more risk factors, including hypertension, elevated blood glucose, dyslipidemia, insulin resistance (IR), and hyperuricemia. IR was assessed by the triglyceride glucose (TyG) index. Multivariable logistic regression models were applied to explore the associations of FMR in the whole body and body parts with single and clustered CRFs.
RESULTS: The odds ratios (ORs) increased significantly for all single and clustered CRFs with the per quartile increase of total and regional FMR in both sexes (P for trend < 0.001), following adjustment for confounders. Among the regional parts, FMRs of the legs presented the strongest associations for clustered CRFs in both men and women, with adjusted OR of 8.54 (95% confidence interval (CI): 7.12-10.24) and 4.92 (95% CI: 4.24-5.71), respectively. Significant interactions (P for interaction < 0.05) were identified between age and FMRs across different body parts, as well as between BMI status and FMRs in different regions for clustered CRFs. Restricted cubic splines revealed significant non-linear relationships between FMRs of different body parts and clustered CRFs in both sexes (P for nonlinear < 0.05).
CONCLUSIONS: FMRs in the whole body and different regions were significantly associated with single and clustered CRFs in the general Chinese population. The association between FMR and clustered CRFs was more pronounced in youngers than in the elderly.

Previous studies have yielded inconsistent results regarding the relationship between obesity and bone mineral density (BMD). The aim of this study was to determine the influence of body composition on BMD and the serum sclerostin level in overweight and obese adults. The study had a cross-sectional design and included 90 men and 118 women with a body mass index ≥25. Fat mass, lean mass, and spinal and pelvic BMD were measured using dual-emission X-ray absorptiometry. Subcutaneous fat, visceral fat, and lean mass were measured between L2 and L3 by 16-slice spiral computed tomography. The serum sclerostin level was determined by enzyme-linked immunosorbent assay. Pearson analysis showed that fat mass and appendicular lean mass were positively correlated with spinal BMD in both sexes. A positive association of both fat mass and lean mass with pelvic BMD, which was stronger in women, was also found. Partial correlation analysis showed the positive association between fat mass and BMD was significantly attenuated but the positive association between lean mass and pelvic BMD remained after adjustment for age and body weight. A negative correlation was observed between visceral fat and spinal and pelvic BMD only in women, and the positive association between lean mass with pelvic BMD was more obvious in women than in men, indicating body composition seemed to have a greater impact on the BMD in women. The serum sclerostin level was positively associated with BMD but not with body composition. These findings suggest that the correlation between body composition and BMD is influenced by sex and skeletal site.

UNASSIGNED: Many studies define obesity based on body mass index (BMI) and explore its relationship with adult asthma. However, BMI only considers height and weight, ignoring other factors such as body fat, which may have a greater impact on health. We investigated the relationship between body fat distribution and adult asthma using both a cross-sectional study and bidirectional Mendelian randomization (MR) analysis.
UNASSIGNED: Weighted logistic regression models were used to examine the relationship between body fat distribution measurements and adult asthma in the cross-sectional study from National Health and Nutrition Examination Survey (NHANES) 2011-2018. Restricted cubic spline (RCS) curves were employed to explore the dose-response relationship between them. The inverse-variance weighted (IVW) method was used as the main method of MR analysis to explore the causal effect of exposure on outcome.
UNASSIGNED: After adjusting for all covariates, weighted logistic regression analysis indicated that fat mass in the left arm, left leg, right arm, right leg, trunk, and total body is associated with an increased risk of developing adult asthma (p < 0.05). RCS curves showed that all six fat mass indicators exhibit a J-shaped relationship with adult asthma. Forward MR analysis found a causal effect of six fat mass indicators on the increased risk of adult asthma (p < 0.05). However, reverse MR did not reveal any causal effect of adult asthma on these six fat mass indicators (p > 0.05).
UNASSIGNED: Our study supports a positive correlation and a unidirectional causality between body fat distribution measurements and the risk of adult asthma. Further studies are needed to validate our findings.

BACKGROUND: Postmenopausal osteoporosis and fractures are widely prevalent. However, the relationship of body composition with bone health in this population remains unclear. The aim of this study was to investigate the association of body composition with bone mineral density (BMD) and 10-year probability of hip fracture in postmenopausal women.
METHODS: This is a cross-sectional study. A total of 1285 subjects were included in our study. Body composition and BMD were assessed using dual-energy X-ray densitometry. The 10-year probability of hip fracture of participants was calculated. All participants were categorized into four groups: sarcopenic-obese (SO) group, sarcopenic-nonobese (S) group, nonsarcopenic-obese (O) group, or nonsarcopenic-nonobese control (C) group. Multivariate analyses and binary logistic regression were conducted to explore the relationship of body composition with BMD and 10-year probability of hip fracture.
RESULTS: Participants in S group were 2.8, 4.7 and 4.8 times more likely to develop osteoporosis in the lumbar spine, the total hip and femoral neck sites, respectively. Lean mass was positively correlated with BMD, wherein lumbar spine BMD was significantly affected by appendicular lean mass, while total hip BMD and femoral neck BMD were mainly influenced by trunk lean mass. Total fat mass was positively associated with total hip and femoral neck BMD, but not with lumbar spine BMD. A significant correlation was observed between lean mass and 10-year probability of hip fracture.
CONCLUSIONS: Changes in body composition in postmenopausal women could affect bone health. A decrease in regional lean mass may be associated with an increased risk of osteoporosis and fractures.

BACKGROUND: Bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) serves as common modalities for body composition assessment. This study was aimed to evaluate the agreement between BIA and DXA measures in UK Biobank.
METHODS: UK Biobank participants with body fat mass (FM) and fat-free mass (FFM) estimates obtained through BIA (Tanita BC418MA) and DXA concurrently were included. Correlation between BIA and DXA-derived estimates were assessed with Lin\'s concordance correlation coefficients. Bland-Altman and Passing-Boblok analyses were performed to quantify the difference and agreement between BIA and DXA. Multivariable linear regression was used to identify predictors influencing the differences. Finally, prediction models were developed to calibrate BIA measures against DXA.
RESULTS: The analysis included 34437 participants (female 51.4%, mean age 64.1 years at imaging assessment). BIA and DXA measurements were highly correlated (Lin\'s concordance correlation coefficient 0.94 for FM and 0.94 for FFM). BIA (Tanita BC418MA) underestimates FM overall by 1.84 kg (23.77 vs. 25.61, p < 0.01), and overestimated FFM overall by 2.56 kg (52.49 vs. 49.93, p < 0.01). The BIA-DXA differences were associated with FM, FFM, BMI and waist circumference. The developed prediction models showed overall good performance in calibrating BIA data.
CONCLUSIONS: Our analysis exhibited strong correlation between BIA (Tanita BC418MA)- and DXA-derived body composition measures at a population level in UK Biobank. However, the BIA-DXA differences were observed at individual level and associated with individual anthropometric measures. Future studies may explore the use of prediction models to enhance the calibration of BIA measures for more accurate assessments in UK Biobank.

UNASSIGNED: Non-alcoholic fatty liver disease (NAFLD) poses a significant global health challenge, necessitating comprehensive exploration of its etiology. This study investigates the intricate relationship between body composition and NAFLD prevalence, focusing on the balance between muscle mass and fat content.
UNASSIGNED: Employing a retrospective cross-sectional design, 2,493 participants undergoing routine health examinations were analyzed. Body compositions, including muscle mass and fat, were measured using bioelectrical-impedance analysis. The prevalence of NAFLD was assessed based on clinical guidelines.
UNASSIGNED: This study included 2,493 patients, including 1,601 (64.2%) men and 892(35.8%) women. The average age of these participants was 46.0 ± 13.1 years, with a mean body mass index of 25.0 ± 3.6 kg/m2. The levels of fat free mass (FFM) to fat mass (FM) ratio (FFM/FM) and appendicular skeletal muscle mass index (ASMI) demonstrated a negative association with the prevalence of NAFLD (OR (95% CI): 0.553 (0.427-0.704) and 0.850 (0.730-0.964), p < 0.001 and p = 0.022, respectively). Liver function further elucidates the multifaceted impact of body composition on hepatic health. In contrast to other parameters, FFM/FM displayed a negative association with liver damage indicators, including a negative association with alanine aminotransferase (Beta±SE: -1.00 ± 0.17, p < 0.001), with aspartate aminotransferase showing borderline significance (Beta±SE: -0.26 ± 0.15, p = 0.084). Similar associations were also evident in terms of liver productive function and bilirubin metabolism.
UNASSIGNED: Our study offers novel insights into the nuanced interplay between body composition and NAFLD. Recognizing the significance of the balance between muscle and fat provides a foundation for tailored interventions that may reshape the landscape of NAFLD prevention and management.

UNASSIGNED: Despite the high risk of eating disorder (ED)-related attitudes and behaviors among female dancers, targeted scientific dietary regimens are currently inadequate. Time-restricted eating (TRE), a popular intermittent fasting protocol, has been shown to be effective in enhancing body composition and exercise performance in athletes. In this study, TRE was employed as a dietary regimen to improve body composition and exercise performance and address ED attitudes and behaviors in DanceSport dancers.
UNASSIGNED: Twenty female DanceSport dancers were recruited and divided into two groups: TRE (n = 10) and normal diet (ND) (n = 10). The TRE group consumed their self-selected necessary energy intake exclusively between 11 a.m. and 7 p.m. (utilizing a 16-hour fasting and 8-hour eating window) for 6 weeks, while the ND group maintained their regular dieting patterns. The consumption of water, black tea, or coffee without added sugar or milk was not restricted. Physical activity and calorie intake were systematically recorded during the TRE intervention. Body composition, aerobic and anaerobic performance, and ED attitudes and behaviors were assessed before and after the TRE intervention. The trial was registered in the Chinese Clinical Trial Registry under the identifier ChiCTR2200063780.
UNASSIGNED: The fixed effects tests (p < 0.0001) and estimates for the intercept (p < 0.0001) of hunger level indicated a noticeable effect on the initial state of hunger during TRE. No significant differences were observed in ED attitudes or behaviors (p > 0.05). TRE resulted in a reduction in hip circumference (p = 0.039), fat mass (kg) (p = 0.0004), and body fat percentage (p = 0.0005), with no significant decrease in fat-free mass (p > 0.05). No significant improvement was observed in aerobic performance (p > 0.05). The average power (AP) (p = 0.01) and AP/Body weight ratio (p = 0.003) significantly increased. Additionally, the power drop decreased significantly (p = 0.019). Group-by-time interactions were observed for fat mass (kg) (p = 0.01), body fat percentage (p = 0.035), and AP/Body weight (p = 0.020).
UNASSIGNED: TRE can be considered a feasible nutritional strategy for DanceSport dancers, facilitating improvements in body composition without compromising aerobic and anaerobic exercise performance or exacerbating ED attitudes and behaviors. Moreover, TRE may facilitate more favorable physiological adaptations, potentially contributing to improved exercise performance.

UNASSIGNED: This study aimed to investigate the glycometabolism, fat mass, and lean mass in primary aldosteronism (PA) during disease progression.
UNASSIGNED: Patients diagnosed with PA and healthy controls (HCs) were enrolled. A flash glucose monitoring system (FGMS) and dual-energy X-ray absorptiometry (DEXA) were used to measure glucose variability and glucose target rate along with fat mass and lean mass. Comparative analysis of FGMS- or DEXA-derived parameters along with correlation analyses between these parameters and PA progression were performed.
UNASSIGNED: Increased glucose variability and poor glucose target rate, along with an increased proportion of truncal fat mass, and decreased proportion of appendicular lean mass, were identified in PA group compared to those in HCs. Plasma aldosterone concentration was positively correlated with glucose variability and poor glucose target rate. Plasma renin concentration was positively correlated with the proportion of truncal fat mass and lean mass, and negatively correlated with the proportion of appendicular fat mass. Aldosterone-to-renin ratio was negatively correlated with the proportion of truncal fat mass and lean mass, and positively correlated with the proportion of appendicular fat mass.
UNASSIGNED: Patients with PA presented significant differences in glycometabolism, fat mass, and lean mass compared with HCs, and these alterations correlated with PA progression.

UNASSIGNED: The oxidative balance score (OBS) is important for determining the cause of obesity and its complications. We aimed to evaluate the association between OBS and obesity and other segmental body composition parameters among young and middle-aged U.S. adults.
UNASSIGNED: 9,998 participants from the National Health and Nutrition Examination Survey 2011-2018 were included. Lean mass percentage (LM%) and FM% were evaluated by dual-energy x-ray absorptiometry. Obesity was defined as body FM% ≥25% in men and ≥ 35% in women. The OBS was scored by 5 pro-oxidant and 21 antioxidant factors. Associations of quartiles of OBS with obesity risk were estimated using multivariable logistic regression models. Multivariable linear regression was conducted to estimate the association between OBS and segmental body composition measures including the arm LM%, leg LM%, torso LM%, whole LM%, arm FM%, leg FM%, torso FM% and total FM%.
UNASSIGNED: Compared to participants in the lowest quartile of OBS, those in the highest quartile of OBS were associated with a lower risk of BMI-defined obesity BMI-defined obesity [0.43 (0.36, 0.50)] and FM%-related obesity [0.43 (0.35, 0.52)]. Additionally, OBS was negatively associated with FM% of the limb and torso but positively associated with the percentage of lean mass (LM%) of the limb and trunk.
UNASSIGNED: OBS was negatively associated with the risk of obesity and segmental FM%, but was positively associated with segmental LM% among US adults, indicating that adhering to an anti-oxidative diet and lifestyle management may be beneficial for preventing segmental obesity.

OBJECTIVE: The findings from previous epidemiological studies of the association between regional body fat and depressive symptoms have been unclear. We aimed to determine the association between the body fat in different regions and depressive symptoms based on data from the National Health and Nutrition Examination Survey (NHANES).
METHODS: This study included 3393 participants aged ≥ 20 years from the NHANES performed during 2011-2018. Depressive symptoms were assessed using the Patient Health Questionnaire-9. The fat mass (FM) was measured in different regions using dual-energy X-ray absorptiometry to determine the total FM, trunk FM, arm FM, and leg FM. The FM index (FMI) was obtained by dividing the FM in kilograms by the square of the body height in meters. Weighted data were calculated in accordance with analytical guidelines. Linear logistic regression models were used to quantify the association between regional FMI and depressive symptoms. Univariate and stratified analyses were also performed.
RESULTS: The participants in this study comprised 2066 males and 1327 females. There were 404 (11.91%) participants with depressive symptoms, who were aged 40.89 ± 11.74 years and had a body mass index of 30.07 ± 7.82 kg/m². A significant association was found between total FMI and depressive symptoms. In the fully adjusted multivariate regression model, a higher total FMI (odds ratio = 2.18, 95% confidence interval [CI] = 1.08-4.39) was related to a higher risk of depressive symptoms, while increased total FMI (β = 1.55, 95% CI = 0.65-2.44, p = 0.001), trunk FMI (β = 0.57, 95% CI = 0.04-1.10, p = 0.036), and arm FMI (β = 0.96, 95% CI = 0.33-1.59, p = 0.004) were significantly associated with PHQ-9 (Patient Health Questionnaire-9) scores, whereas the leg FMI was not (p = 0.102). The weighted association between total FMI and depressive symptoms did not differ significantly between most of the subpopulations (all p values for interaction > 0.05). The risk of having depression was higher in individuals who were non-Hispanic Whites, smokers, drinkers, obese, and had diabetes and thyroid problems (p < 0.05).
CONCLUSIONS: These findings suggest that the population with a higher regional FMI is more likely to have depressive symptoms, especially in those who also have an increased total FMI. The association is more pronounced in individuals who are smokers, drinkers, obese, and have diabetes and thyroid problems.