Total and regional fat-to-muscle mass ratio measured by bioelectrical impedance and risk of incident type 2 diabetes

Association of muscle mass, grip strength and fat-to-muscle ratio and metabolic dysfunction-associated steatotic liver disease in a middle-to-elderly aged population

OBJECTIVE

The association of appendicular skeletal muscle mass (ASM), grip strength and fat-to-muscle ratio (FMR) and the progression of metabolic dysfunction-associated steatotic liver disease (MASLD) are not well known.

MATERIALS AND METHODS

This study included participants older than 40 years who underwent bioelectrical impedance assessment in Prevalence of Metabolic Diseases and Risk Factors in Shunde (SPEED-Shunde). We measured grip strength with an electronic grip strength metre. ASM and grip strength were adjusted by dividing body mass index (BMI). FMR was calculated as total fat mass to total muscle mass. Liver steatosis and liver fibrosis were evaluated by vibration-controlled transient elastography. Multifactorial logistic regression was used to analyse the relationship between ASM, grip strength, FMR, and MASLD or MASLD-associated liver fibrosis. We performed subgroup analyses according to sex, age and BMI. Interaction tests and linear trend tests were also conducted.

RESULTS

This study included a total of 3277 participants. FMR was positively associated with MASLD (OR: 1.89, 95% CI: 1.66-2.15) and MASLD-associated liver fibrosis (OR: 1.70, 95% CI: 1.22-2.37). While ASM/BMI (OR: 0.59, 95% CI: 0.52-0.67) or grip strength/BMI (OR: 0.72, 95% CI: 0.66-0.78) were negatively associated with MASLD. Interactions were observed between ASM/BMI and age, grip strength and sex in MASLD, as well as FMR and MASLD-associated liver fibrosis.

CONCLUSION

In a middle-to-elderly aged population, FMR was positively associated with the risk of MASLD and MASLD-associated liver fibrosis, and muscle mass and grip strength were negatively associated with MASLD, rather than MASLD-associated liver fibrosis.

Impact of fat to muscle ratio with risk of disability on community-dwelling Japanese older adults: A 5-year longitudinal study

PURPOSE

Sarcopenic obesity is a combination of sarcopenia and obesity, which is associated with the onset of disability. Fat to muscle ratio (FMR) is a screening measure that assesses the ratio of muscle mass to fat mass. However, the relationship between the FMR and disability has not been investigated.

METHODS

This study included 11,427 community-dwelling older adults aged ≥65 years enrolled in NCGG-SGS (National Center for Geriatrics and Gerontology-Study of Geriatric Syndromes), a national cohort study in Japan. FMR was measured by the bioelectrical impedance analysis and calculated by dividing fat mass by muscle mass. Cox proportional hazard regression analysis adjusted for covariates was used to investigate the association between FMR and the risk of developing new care needs at 5 years. FMR was divided by about quintile, with quintile 5 as the high.

RESULTS

The high FMR group had the highest incidence of disability at 20.8 % for women and 20.1 % for men. In women, the association between FMR and disability was significantly different for the FMR (hazard risk [HR]: 1.43, 95 % confidence interval [CI]: 1.16-1.75). There was no association between FMR and disability in men (HR: 0.98, 95 %CI: 0.76-1.25). Lagged analyses accounting for reverse causality did not change the relationship.

CONCLUSIONS

FMR is associated with increased risk of disability in women community-dwelling older adults but not among men. Because the rate of decreased muscle strength is faster in men than in women, early decreased muscle strength may affect men's risk of disability more than muscle mass or fat mass.

Fatty liver index and somatic composition in subjects receiving medical health checkup

AIMS

To elucidate the relationship between fatty liver index (FLI) and somatic composition among health checkup recipients (4533 men and 4877 women).

METHODS

Fat (F) index, fat-free (FF) index, and fat mass to fat-free mass (F-FF) ratio was measured by bioimpedance analysis. Skeletal muscle mass (SMM) loss was defined as FF index <18 kg/m2 in men and FF index <15 kg/m2 in women. The impact of FLI on the somatic composition (i.e., F index, FF index, and F-FF ratio) was retrospectively investigated.

RESULTS

The median age in men and women was 54 and 52 years (p < 0.0001). The median body mass index in men and women was 23.4 and 21.1 kg/m2 (p < 0.0001). The prevalence of fatty liver on ultrasonography was 52.5% in men and 22.1% in women. The median FLI in men and women was 25.1 and 6.9 (p < 0.0001). Fatty liver index correlated significantly with F index (r > 0.5 in all analyses). In all analyses, the decreased SMM group had significantly lower FLI than the nondecreased SMM group. In receiver operating characteristic (ROC) curve analysis for the SMM decrease, in both genders, area under the ROCs of FLI were all over 0.80 (optimal cut-off point: 19.7 in men and 8.4 in women). The FLI correlated significantly with F-FF ratio (r > 0.5 in all analyses).

CONCLUSION

The FLI can be a good indicator of not only fat mass but also FF mass and body composition balance in health checkup subjects. The FLI may not be just a marker of hepatic steatosis.

Sex-specific associations between total and regional Fat-to-muscle Mass ratio and cardiometabolic risk: findings from the China National Health Survey

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.

A cohort study on the predictive capability of body composition for diabetes mellitus using machine learning

Purpose

We applied machine learning to study associations between regional body fat distribution and diabetes mellitus in a population of community adults in order to investigate the predictive capability. We retrospectively analyzed a subset of data from the published Fasa cohort study using individual standard classifiers as well as ensemble learning algorithms.

Methods

We measured segmental body composition using the Tanita Analyzer BC-418 MA (Tanita Corp, Japan). The following features were input to our machine learning model: fat-free mass, fat percentage, basal metabolic rate, total body water, right arm fat-free mass, right leg fat-free mass, trunk fat-free mass, trunk fat percentage, sex, age, right leg fat percentage, and right arm fat percentage. We performed classification into diabetes vs. no diabetes classes using linear support vector machine, decision tree, stochastic gradient descent, logistic regression, Gaussian naïve Bayes, k-nearest neighbors (k = 3 and k = 4), and multi-layer perceptron, as well as ensemble learning using random forest, gradient boosting, adaptive boosting, XGBoost, and ensemble voting classifiers with Top3 and Top4 algorithms. 4661 subjects (mean age 47.64 ± 9.37 years, range 35 to 70 years; 2155 male, 2506 female) were analyzed and stratified into 571 and 4090 subjects with and without a self-declared history of diabetes, respectively.

Results

Age, fat mass, and fat percentages in the legs, arms, and trunk were positively associated with diabetes; fat-free mass in the legs, arms, and trunk, were negatively associated. Using XGBoost, our model attained the best excellent accuracy, precision, recall, and F1-score of 89.96%, 90.20%, 89.65%, and 89.91%, respectively.

Conclusions

Our machine learning model showed that regional body fat compositions were predictive of diabetes status.

Association of fat-to-muscle mass ratio with physical activity and dietary protein, carbohydrate, sodium, and fiber intake in a cross-sectional study

Higher fat-to-muscle mass ratio (FMR) is reported to be a risk factor for various diseases, including type 2 diabetes and cardiovascular diseases, and mortality. Although this association suggests that reducing FMR may help to prevent certain diseases and mortality, the relationship between FMR and lifestyle factors is unclear. Therefore, we performed a cross-sectional study with the aim to elucidate this relationship. This cross-sectional study included 1518 healthy Japanese adults aged 30 to 64 years. We measured FMR in the whole body, arms, legs, and trunk and assessed various lifestyle factors. Then, we performed forced entry multiple regression analyses for FMR with the following variables: sex, age, physical activity, dietary intake, sleep quality, cigarette smoking, stress levels, and body mass index. As a result, whole-body and regional FMRs were correlated with female sex (β = 0.71); age (β = 0.06); physical activity (β = - 0.07); dietary intake of protein (β = - 0.12), carbohydrate (β = 0.04), sodium (β = 0.13), and fiber (β = - 0.16); and body mass index (β = 0.70). The results suggest that in the Japanese middle-aged population, low FMR is associated with certain lifestyle factors, i.e. higher physical activity and a diet with higher protein and fiber and lower carbohydrate and sodium, independent of age, sex, and body mass index.

Long-term exposure to ambient air pollution and incident gout: A prospective cohort study in the UK Biobank

Gout is a chronic disorder characterized by the accumulation of uric acid in the body, leading to recurrent episodes of joint inflammation and pain. There remains a lack of studies investigating the association between long-term exposure to ambient air pollution and the incidence of gout. We conducted this prospective cohort study involving participants aged 38-70 from the UK Biobank who were enrolled in 2006-2010 and followed until 2023. Baseline residential concentrations of fine particulate matter (PM2.5), inhalable particulate matter (PM10), nitrogen dioxide (NO2) and nitrogen oxides (NOx) were predicted using land-use regression models. Cox proportional hazards models were employed to examine the relationship between air pollution and incident gout events. A total of 443,587 individuals were included in the analyses and a total of 6589 incident gout cases were identified over a follow-up of 6,130,439 person-years. There were significant associations between higher levels of air pollution and an increased incidence risk of gout. Higher risk of incident gout was associated with each interquartile range increase in concentrations of PM2.5 (hazard ratio:1.05, 95% confidence intervals: 1.02-1.09), PM10 (1.04, 1.00-1.07), NO2 (1.08, 1.05-1.12) and NOx (1.04, 1.02-1.07). The magnitude of associations was larger at higher concentrations. The association was more prominent among older adults, smokers, and individuals with lower and moderate physical activity. This prospective cohort study provides novel and compelling evidence of increased risk of incident gout associated with long-term air pollution exposures.

The association of a healthy lifestyle index and imaging-based body fat distribution with glycemic status and Type 2 diabetes in the Multi Ethnic Cohort: a cross-sectional analysis

INTRODUCTION

As several behaviors captured by the Lifestyle Risk Factor Index (LSRI) are protective against Type 2 diabetes (T2D) and may affect body fat distribution, we examined its relation with both outcomes.

METHODS

In a subset of the Multiethnic Cohort, participants from five ethnic groups (60-77 years) were assigned LSRI scores (one point each for consuming <1 (women)/<2 (men) alcoholic drinks/day, ≥1.5 physical activity hours/week, not smoking, and adhering to ≥3/7 dietary recommendations). All participants completed an extensive Quantitative Food Frequency Questionnaire to allow estimation of adherence to intake recommendations for fruits, vegetables, refined and whole grains, fish, processed and non-processed meat. Glycemic/T2D status was classified according to self-reports and fasting glucose. We estimated prevalence odds ratios (POR) of LSRI with glycemic/T2D status and DXA- and MRI-based body fat distribution using logistic regression.

RESULTS

Of 1713 participants, 43% had normoglycemia, 30% Pre-T2D, 9% Undiagnosed T2D, and 18% T2D. Overall, 39% scored 0-2, 49% 3, and 12% 4 LSRI points. T2D prevalence was 55% (POR 0.45; 95% confidence intervals 0.27, 0.76) lower for 4 vs. 0-2 LSRI points with weaker associations for abnormal glycemic status. Despite the low adherence to dietary recommendations (22%), this was the only component related to lower T2D prevalence. The inverse LSRI-T2D association was only observed among Latinos and Japanese Americans in ethnic-specific models. Visceral fat measures were higher in T2D patients and attenuated the LSRI-T2D association.

CONCLUSION

These findings support the role of a healthy lifestyle, especially diet, in T2D prevention with differences across ethnicity.

Sex-specific associations between skeletal muscle mass and incident diabetes: A population-based cohort study

AIMS

To investigate the sex-specific associations between predicted skeletal muscle mass index (pSMI) and incident type 2 diabetes in a retrospective longitudinal cohort of Chinese men and women.

MATERIALS AND METHODS

We enrolled Chinese adults without diabetes at baseline from WATCH (West chinA adulT health CoHort), a large health check-up-based database. We calculated pSMI to estimate skeletal muscular mass, and measured blood glucose variables and assessed self-reported history to identify new-onset diabetes. The nonlinear association between pSMI and incident type 2 diabetes was modelled using the penalized spline method. The piecewise association was estimated using segmented linear splines in weighted Cox proportional hazards regression models.

RESULTS

Of 47 885 adults (53.2% women) with a median age of 40 years, 1836 developed type 2 diabetes after a 5-year median follow-up. In women, higher pSMI was associated with a lower risk of incident type 2 diabetes (Pnonlinearity  = 0.09, hazard ratio [HR] per standard deviation increment in pSMI: 0.79 [95% confidence interval {CI} 0.68, 0.91]). A nonlinear association of pSMI with incident type 2 diabetes was detected in men (Pnonlinearity  < 0.001). In men with pSMI lower than 8.1, higher pSMI was associated with a lower risk of incident type 2 diabetes (HR 0.58 [95% CI 0.40, 0.84]), whereas pSMI was not significantly associated with incident diabetes in men with pSMI equal to or greater than 8.1 (HR 1.08 [95% CI 0.93, 1.25]).

CONCLUSIONS

In females, a larger muscular mass is associated with a lower risk of type 2 diabetes. For males, this association is significant only among those with diminished muscle mass.

Glucose metabolism in gestational diabetes and their relationship with fat mass / muscle mass index

Introduction

During pregnancy, women experience metabolic changes that may induce insulin resistance, which can be traced to the blood glucose levels A number of factors may intervene in the metabolism of glucose in pregnant women; one of them is body composition. This factor is useful for studying metabolic diseases, for which the identification of the fat mass/muscle mass index (FMMMI) considered an especially relevant factor. Owing to their nature, techniques such as bioimpedance have been sparsely used for analysis during pregnancy.

Aim

This study aimed to identify the relationship between fat mass / muscle mass index and glucose metabolism in pregnant women.

Methods

This descriptive cross-sectional study included 231 women between the ages of 18 and 35 years and 24-28 weeks of gestation, who attended a state hospital for regular check-ups and exhibited risk factors for the development of gestational diabetes (GD) according to the Current Practice Guidelines in Primary Care. The participants underwent a physical examination, anthropometric measurements bio impedance were obtained, and oral glucose tolerance curves were constructed. FMMMI was calculated.

Results

The prevalence of gestational diabetes was observed to be 13.4%. Women with a GD diagnosis had a significantly higher FMMMI than in those with no GD (0.746 ± 0.168 vs 0.567 ± 0.167;p < 0.005). The assessment of the FMMMI tertiles revealed that GD prevalence was higher in tertile 3 than in tertiles 1 and 2 (tertile 1: 2.6%; tertile 2: 9.1%; tertile 3: 24%).

Conclusion

FMMMI is associated with glucose tolerance test response in pregnant women and a higher prevalence of GD.

Donor fat-to-muscle ratio and kidney transplant outcomes: A proposition of metabolic memory

AIMS

The impact of donor abdominal fat-to-muscle ratio (FMR) on kidney transplant (KT) outcomes was assessed. Given the transient nature of the donor's metabolic environment in transplant recipients, this study investigated the capacity of body composition to induce metabolic memory effects.

MATERIALS AND METHODS

KT patients (n = 895) who received allografts from living donors (2003-2013) were included. Donor fat and muscle were quantified using pre-KT abdominal computed tomography scans. Patients were categorised into donor FMR tertiles and followed up for graft outcomes. Additionally, genome-wide DNA methylation analysis was performed on 28 kidney graft samples from KT patients in the low- and high-FMR groups.

RESULTS

Mean recipient age was 42.9 ± 11.4 years and 60.9% were males. Donor FMR averaged 1.67 ± 0.79. Over a median of 120.9 ± 42.5 months, graft failure (n = 127) and death-censored graft failure (n = 109) were more frequent in the higher FMR tertiles. Adjusted hazard ratios for the highest versus lowest FMR tertile were 1.71 (95% CI, 1.06-2.75) for overall graft failure and 1.90 (95% CI, 1.13-3.20) for death-censored graft failure. Genome-wide DNA methylation analysis identified 58 differentially methylated regions (p < 0.05, |Δβ| > 0.2) and 35 genes showed differential methylation between the high- (FMR >1.91) and low-FMR (FMR <1.27) groups.

CONCLUSIONS

Donors with increased fat and reduced muscle composition may negatively impact kidney allograft survival in recipients, possibly through the transmission of epigenetic changes, implying a body-composition-related metabolic memory effect.

Fat-to-muscle ratio is associated with insulin resistance and cardiometabolic disorders in adults with type 1 diabetes mellitus

AIMS

This study aimed to investigate the correlation of the fat-to-muscle ratio (FMR) with insulin resistance (IR) and cardiometabolic disorders (CMD) in patients with type 1 diabetes mellitus (T1DM).

MATERIALS AND METHODS

We retrospectively recruited 420 adults with T1DM [52.6% men, median age 32.4 (24.5, 43.0) years]. Body composition was assessed by bioelectrical impedance analysis and FMR was calculated. The characteristics of the overall participants were compared between tertiles of FMR. Logistic regression analyses were performed to assess the association of FMR tertiles with IR and cardiometabolic risk factors.

RESULTS

Median age and median haemoglobin A1c of all participants were 32.4 (24.5, 43.0) years and 7.4 (6.5, 8.7)%, respectively. The prevalence of IR and CMD was 18% and 38.6%. The FMR significantly differed between men and women [0.39 (0.31, 0.53) vs. 0.74 (0.63, 0.92), respectively, p < .001]. The proportion of IR and CMD gradually increased as the FMR increased. The multivariable-adjusted odd ratios for IR and CMD in FMR tertile 3 compared with tertile 1 were 4.8 [95% confidence interval (CI): (1.9, 12.1)] and 9.7 (95% CI: 4.2, 22.3), respectively, in men. For women, the corresponding odd ratios were 4.0 (95% CI: 1.2, 12.9) for IR and 5.8 (95% CI: 2.4, 13.6) for CMD.

CONCLUSIONS

FMR is associated with IR and CMD in adults with T1DM and could be used as a promising parameter for targeting treatment in T1DM.

The serum creatinine to cystatin C to waist circumference ratios predicts risk for type 2 diabetes: A Chinese cohort study

BACKGROUND

There is a lack of research regarding the relationship between creatinine to cystatin C to waist circumference ratio (CCR/WC ratios) and the development of type 2 diabetes mellitus (T2DM). We aimed to evaluate the association between CCR/WC ratios and incident T2DM in Chinese adults.

METHODS

This prospective study was from the China Health and Retirement Longitudinal Study (2011, 2013, 2015, and 2018). The participants were divided into three groups by tertiaries of the CCR/WC ratios. Cox proportional-hazards models were used to identify the relationship between CCR/WC and T2DM.

RESULTS

Overall, 5938 participants were included for analysis, 766 of whom developed T2DM between 2011 and 2018. Risk of incident T2DM was decreased with tertiaries 2, 3 versus tertiary 1 of the CCR/WC index (adjusted hazard ratio [HR] 0.772 [95% confidence interval 0.647-0.921] and 0.724 [0.596-0.880], p for trend = .001 across tertiaries of the CCR/WC index). The results were consistent excluding participants with T2DM in the first 2 years.

CONCLUSIONS

This study demonstrated that CCR/WC was negatively correlated with the risk of T2DM in Chinese adults. Early detection is necessary to control the development of T2DM in Chinese with low CCR/WC levels.

Total and Regional Fat/Muscle Mass Ratio and Risks of Incident Cardiovascular Disease and Mortality

Background To evaluate the sex-specific associations of total and regional fat/muscle mass ratio (FMR) with cardiovascular disease (CVD) incidence and mortality, and to explore the underlying mechanisms driven by cardiometabolites and inflammatory cells. We compared the predictive value of FMRs to body mass index. Methods and Results This population-based, prospective cohort study included 468 885 UK Biobank participants free of CVD at baseline. Fat mass and muscle mass were estimated using a bioelectrical impedance assessment device. FMR was calculated as fat mass divided by muscle mass in corresponding body parts (total body, trunk, arm, and leg). Multivariable Cox proportional hazards models and mediation analyses were used. During 12.5 years of follow-up, we documented 49 936 CVD cases and 4158 CVD deaths. Higher total FMR was associated with an increased risk of incident CVD (hazard ratios [HRs] were 1.63 and 1.83 for men and women, respectively), ischemic heart disease (men: HR, 1.61; women: HR, 1.81), myocardial infarction (men: HR, 1.72; women: HR, 1.49), and congestive heart failure (men: HR, 2.25; women: HR, 2.57). The positive associations of FMRs with mortality from total CVD or its subtypes were significant mainly in trunk and arm for male patients (P for trend <0.05). We also identified 8 cardiometabolites and 5 inflammatory cells that partially mediated FMR-CVD associations. FMRs were modestly better at discriminating cardiovascular mortality risk. Conclusions Higher total and regional FMRs were associated with an increased risk of CVD and mortality, partly mediated through cardiometabolites and inflammatory cells. Early monitoring of FMR should be considered to alleviate CVD risk. FMRs were superior to body mass index in predicting CVD mortality.

The association between muscle-to-fat ratio and cardiometabolic risks: The China National Health Survey

BACKGROUND

The relationship between muscle mass and fat mass might be an indicator to assess the cardiometabolic risk independently from overweight/obesity, but evidence from a representative general Chinese population is lacking.

OBJECTIVE

To understand the age- and sex-specific associations between muscle-to-fat ratio (MFR) and cardiometabolic risks in Chinese population.

METHODS

31,178 (12,526 men and 18,652 women) subjects from the China National Health Survey were included. Muscle mass and fat mass were assessed by a bioelectrical impedance device. MFR was calculated as muscle mass divided by fat mass. Systolic blood pressure (SBP) and diastolic blood pressure (DBP), serum lipids, fasting plasma glucose and serum uric acid were measured. General linear regressions, quantile regressions and restricted cubic-spline (RCS) regressions were applied to assess the effect of MFR on cardiometabolic profiles.

RESULTS

Per unit increase of MFR was associated with a 0.631 (0.759-0.502) mmHg SBP decrease in men, 2.648 (3.073-2.223) in women; 0.480 (0.568-0.392) mmHg DBP decrease in men, 2.049 (2.325-1.774) in women; a 0.054 (0.062-0.046) mmol/L total cholesterol decrease in men, 0.147 (0.172-0.122) in women; 0.084 (0.098-0.070) mmol/L triglycerides decrease in men, 0.225 (0.256-0.194) in women; a 0.045 (0.054-0.037) mmol/L low-density lipoprotein decrease in men, 0.183 (0.209-0.157) in women; a 2.870 (2.235-3.506) μmol/L serum uric acid decrease in men, 13.352 (14.967-11.737) in women; and a 0.027 (0.020-0.033) mmol/L high-density lipoprotein increase in men, 0.112 (0.098-0.126) mmol/L in women. The effect in overweight/obese people was much significant than in under/normal weight counterparts. The RCS curves revealed both linear and non-linear relationships between increased MFR and lower cardiometabolic risk.

CONCLUSIONS

Muscle-to-fat ratio is independently associated with multiple cardiometabolic parameters among Chinese adults. Higher MFR is related with better cardiometabolic health, and the effect is much significant in overweight/obese people and women.

Relationships of BMI, muscle-to-fat ratio, and handgrip strength-to-BMI ratio to physical fitness in Spanish children and adolescents

This study aimed to determine the relationship of body mass index (BMI), muscle-to-fat ratio (MFR), and handgrip strength-to-BMI ratio to physical fitness parameters in an active young population according to sex across four different time points. A total of 2256 Spanish children and adolescents (aged 5-18) from rural areas participating in an extracurricular sport in different municipal sports schools participated in this study. Participants were divided into children (5-10 years) and adolescents (11-18 years), boys and girls, and across four different time points (2018, 2019, 2020, 2021). Data on anthropometric measures (BMI, MFR, appendicular skeletal muscle mass) and physical fitness (handgrip strength, cardiorespiratory fitness, and vertical jump) were collected. Boys who were overweight, but especially boys with obesity, had higher absolute handgrip strength in children and adolescents than their normal weight counterparts in 2020 and 2021. Boys and girls with normal weight presented higher cardiorespiratory fitness and vertical jump than their overweight and obese peers over the years. The MFR was directly correlated with the cardiorespiratory fitness and vertical jump variables, but not with handgrip strength, in boys and girls. The handgrip strength-to-BMI ratio in both sexes was positively correlated to the different physical fitness parameters.  Conclusion: BMI, MFR, and handgrip strength-to-BMI can be used as health and physical fitness indicators in this population. What is Known: • BMI is the main indicator commonly used as a proxy for obesity for many years. Nevertheless, it cannot differentiate between fat mass and fat-free mass. • There are other indicators such as MFR and handgrip strength-to-BMI that might be more accurate and can serve to monitor the health and fitness of children and adolescents. What is New: • MFR showed a positive and significant correlation with cardiorespiratory fitness and vertical jump in both sexes. On the other hand, the handgrip strength-to-BMI presented a positive correlation with cardiorespiratory fitness, vertical jump, and handgrip strength. • The use of these indicators obtained through different parameters of body composition and physical fitness can serve as a tool to identify the relationships of the paediatric population with physical fitness.

Age-specific and sex-specific associations of visceral adipose tissue mass and fat-to-muscle mass ratio with risk of mortality

BACKGROUND

Limited studies have explored the association between visceral adipose tissue (VAT) mass and fat-to-muscle mass ratio (FMR) and mortality. We aimed to evaluate the sex-specific association of VAT and FMR with all-cause and cause-specific mortality by age.

METHODS

A total of 438 896 participants (49.8% men, mean age ± standard deviation: 57 ± 8 years for men; 56 ± 8 years for women) were included from the UK Biobank cohort. The nature of VAT was predictive, as obtained by sex-stratified, non-linear prediction models. Fat and muscle mass were estimated using a bioelectrical impedance assessment device. FMR was calculated as the fat mass divided by the muscle mass in the whole body. VAT and FMRs were divided into quintiles in ascending order, and the 3rd quintile was used as the reference. Cox regression analyses were used to estimate the associations between VAT, FMR and mortality.

RESULTS

During a median of 12.4 years of follow-up, we documented 29 903 deaths. After adjusting for various covariates, the individuals in the highest quintiles of VAT and FMR had the highest hazard ratios (HRs) of all-cause mortality [1.24 (95% confidence interval: 1.17-1.33) for VAT and 1.24 (1.17-1.31) for FMR in men; and 1.11 (1.03-1.21) for VAT in women], except that the 1st quintile of FMR in women had the greatest HR [1.18 (1.09-1.27)]. Significant interactions were observed in both sexes according to age category (P for interaction < 0.05). Among men <50 years, participants in the 1st and 5th quintiles of VAT and FMR had significantly higher risks of mortality [1.30 (1.02-1.66) and 1.67 (1.27-2.19) in VAT; 1.25 (0.99-1.56) and 1.41 (1.11-1.79) in FMR, respectively]; in women, this phenomenon was observed in the ≥60 age group [1.16 (1.06-1.27) and 1.19 (1.08-1.31) in VAT; 1.18 (1.08-1.29) and 1.11 (1.01-1.22) in FMR, respectively]. VAT showed a linear positive association with mortality in women <60 years and a J-shaped association from respiratory disease in both sexes ≥60 years. FMR showed a linear positive association with mortality from cancer in men <60 years and a J-shaped association with mortality from cause-specific mortality in both sexes ≥60 years, except for mortality from cardiovascular disease in men.

CONCLUSIONS

Most associations of VAT and FMR with all-cause mortality were J-shaped and were significantly modified by age status (<50, 50-59 and ≥60 years). The clinical implication is that regarding body composition and VAT mass, different health strategies may be adopted for people of different sexes and ages.

Association between trunk-to-peripheral fat ratio and renal function in elderly Japanese men: baseline data from the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study

BACKGROUND

Central obesity as measured by waist-to-hip circumference ratio (WHR) has been reported to be associated with renal hemodynamics and function. However, the adipose component of WHR, which is a composite measure of fat mass and fat-free mass, is small, particularly in nonobese subjects. Trunk-to-peripheral fat ratio as measured using dual-energy absorptiometry (DXA) is a more precise method for evaluating central fat distribution than WHR. The present study investigated the cross-sectional association between DXA-measured trunk-to-peripheral fat ratio and estimated glomerular filtration rate (eGFR) in community-dwelling elderly Japanese men.

METHODS

Participants were 575 men aged ≥65 years at the time of the baseline survey of the second Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) cohort study. Trunk-to-appendicular fat ratio (TAR) was calculated as trunk fat divided by appendicular fat (sum of arm and leg fat), and trunk-to-leg fat ratio (TLR) as trunk fat divided by leg fat.

RESULTS

eGFR values significantly decreased from the lowest to the highest quintile of TAR/TLR. After adjusting for potential confounding factors including whole-body fat, the highest quintile of both TAR and TLR showed statistically significant odds ratios for the risk of eGFR <60 ml/min/1.73 m², relative to the lowest quintile. In addition, a significant decreasing trend was observed for eGFR values from the lowest to the highest quintile of TAR/TLR after adjusting for confounding factors including whole-body fat.

CONCLUSION

Elderly men with a large trunk-to-peripheral fat ratio tended to have a lower eGFR. This association occurred independently of that between whole-body fat and eGFR.

Current Knowledge on the Pathophysiology of Lean/Normal-Weight Type 2 Diabetes

Since early times, being overweight and obesity have been associated with impaired glucose metabolism and type 2 diabetes (T2D). Similarly, a less frequent adult-onset diabetes in low body mass index (BMI) people has been known for many decades. This form is mainly found in developing countries, whereby the largest increase in diabetes incidence is expected in coming years. The number of non-obese patients with T2D is also on the rise among non-white ethnic minorities living in high-income Western countries due to growing migratory flows. A great deal of energy has been spent on understanding the mechanisms that bind obesity to T2D. Conversely, the pathophysiologic features and factors driving the risk of T2D development in non-obese people are still much debated. To reduce the global burden of diabetes, we need to understand why not all obese people develop T2D and not all those with T2D are obese. Moreover, through both an effective prevention and the implementation of an individualized clinical management in all people with diabetes, it is hoped that this will help to reduce this global burden. The purpose of this review is to take stock of current knowledge about the pathophysiology of diabetes not associated to obesity and to highlight which aspects are worthy of future studies.

Fat-to-Muscle Ratio Is Independently Associated with Hyperuricemia and a Reduced Estimated Glomerular Filtration Rate in Chinese Adults: The China National Health Survey

BACKGROUND

The effects of the fat-to-muscle ratio (FMR) on hyperuricemia and a reduction in the estimated glomerular filtration rate (eGFR) are still unclear.

METHODS

Data from the China National Health Survey were used to explore the associations of the FMR with hyperuricemia and reduced eGFR. The fat mass and muscle mass were measured through bioelectrical impedance analysis. Mediation analysis was used to estimate the mediated effect of hyperuricemia on the association between the FMR and reduced eGFR.

RESULTS

A total of 31171 participants were included. For hyperuricemia, compared with the Q1 of the FMR, the ORs (95% CI) of Q2, Q3 and Q4 were 1.60 (1.32-1.95), 2.31 (1.91-2.80) and 2.71 (2.15-3.43) in men and 1.91 (1.56-2.34), 2.67 (2.12-3.36) and 4.47 (3.40-5.89) in women. For the reduced eGFR, the ORs (95% CI) of Q2, Q3 and Q4 of the FMR were 1.48 (1.18-1.87), 1.38 (1.05-1.82) and 1.45 (1.04-2.04) in men aged 40-59, but no positive association was found in younger men or in women. Hyperuricemia mediated the association between the FMR and reduced eGFR in men. The OR (95% CI) of the indirect effect was 1.08 (1.05-1.10), accounting for 35.11% of the total effect.

CONCLUSIONS

The FMR was associated with hyperuricemia and reduced eGFR, and the associations varied based on sex and age. The effect of the FMR on the reduced eGFR was significantly mediated by hyperuricemia in men.

Total and regional fat-to-muscle mass ratio and risks of incident all-cause dementia, Alzheimer's disease, and vascular dementia

BACKGROUND

The fat-to-muscle mass ratio (FMR), which integrates the antagonistic effects of fat and muscle mass, has been proposed as a useful indicator to assess disease risk independent of overall obesity. However, little is known about the association between FMR and dementia risk. We aimed to prospectively investigate the sex-specific associations between total and regional FMR and incident dementia.

METHODS

A total of 491 420 participants (223 581 men and 267 839 women; mean age 56.7 ± 8.2 and 56.3 ± 8.0 years old, respectively) free of dementia at baseline from the UK Biobank were included. Fat mass and muscle mass were measured using a bioelectrical impedance assessment device. Cox regression analyses were used to examine the associations of total and regional FMR with incident all-cause dementia, Alzheimer's disease (AD) and vascular dementia (VD). The shape of the associations of the continuous scale of FMR and incident dementia were examined using restricted cubic spline analysis.

RESULTS

During a median 8.65 years of follow-up, we documented 2 225 incident all-cause dementia cases, including 836 AD and 468 VD cases. There was an L-shaped association between whole body FMR and all-cause dementia risk in both sexes after adjusting body mass index (BMI) and other covariates (P for non-linear <0.001 in men and women), where all-cause dementia risk decreased steeply with increasing FMR and levelled off at around the medians (0.35 in men, 0.61 in women) with a hazard ratio (HR) of 0.78 (95% CI: 0.64, 0.96; P = 0.019) and 0.60 (0.47, 0.77; <0.001) per 1 standard deviation (SD) increase in men and women, respectively. Compared with other body parts, FMR of the leg showed the strongest inverse associations [HR (95% CI; P) per 1 SD below the medians: 0.60 (0.48, 0.75; <0.001); 0.61 (0.47, 0.79; <0.001) in men and women, respectively]. Specifically, the inverse associations of whole body FMR on all-cause dementia risk were significant only among participants over the age of 60 (P for trend <0.001). Multivariable adjusted Cox models showed inverse associations of whole body FMR with AD in men only (P for trend = 0.003), whereas no statistically significant decrease was detected in VD among men and women.

CONCLUSIONS

Our analyses provide strong evidence for L-shaped associations of total and regional FMR with the development of dementia among participants aged 60 years or older independent of overall obesity.

The impact of body composition and fat distribution on blood pressure in young and middle-aged adults

Background

The relative contributions of each component of body composition to blood pressure (BP) remain unclear.

Objective

We aimed to comprehensively investigate the impact of body composition and fat distribution on BP and quantify their relative contributions to BP in a large cohort with young and middle-aged adults.

Methods

14,412 participants with available data on whole-body DXA measurement from the National Health and Nutrition Examination Survey were included. Multiple stepwise linear regressions of BP on components of body composition and fat distribution were built. Then, relative importance analysis was performed to quantify the contributions of each component to BP.

Results

The median age of participants was 36 years and there were 50.7% women. Linear regression with mutual adjustment showed that total fat mass, total muscle mass, and trunk fat mass significantly and positively associated with BP; however, arm and leg fat mass significantly and negatively associated with BP. In men, after further adjusted for potential covariates, SBP were significantly determined by trunk fat mass (β = 0.33, P < 0.001), leg fat mass (β = − 0.12, P < 0.001), and total muscle mass (β = 0.10, P < 0.001); and DBP were significantly determined by trunk fat mass (β = 0.52, P < 0.001), leg fat mass (β = −0.15, P < 0.001), arm fat mass (β = −0.23, P < 0.001), and total muscle mass (β = 0.06, P < 0.001). Similar results were observed in women. Relative importance analysis showed that trunk fat mass was the major contributor (38–61%) to both SBP and DBP; meanwhile, total muscle mass also made relatively great contribution (35–43%) to SBP.

Conclusion

Both fat mass and muscle mass independently associated with and substantially contributed to SBP in both men and women. After full adjustment, trunk fat mass positively associated with both SBP and DBP, and was the most dominant contributor to BP; however, leg fat mass negatively associated with both SBP and DBP.

Short Sleep Duration Was Associated with Increased Regional Body Fat in US Adults: The NHANES from 2011 to 2018

Background: The relationship between sleep duration and different regional fat is unclear. We aimed to investigate the association between sleep duration and different regional fat mass (FM) among a population of US adults. Methods: 9413 participants were included from the National Health and Nutrition Examination Survey (NHANES), from 2011 to 2018. The sleep duration was divided into short sleep (<7 h/day), normal sleep (7−9 h/day) and long sleep (>9 h/day). Different regional FM was measured by dual-energy X-ray absorptiometry, including trunk FM, arms FM and legs FM. Fat mass index (FMI) was obtained by dividing FM (kg) by the square of body height (m2). Multiple linear regression was used to evaluate the relationship between sleep duration and regional FMI. Results: The mean sleep duration was 7.1 ± 1.5 h/day. After adjusting for socio-demographic, lifestyle information, comorbid diseases and medications, short sleepers had higher trunk FMI (β = 0.134, 95% confidence interval (CI): 0.051−0.216, p = 0.001), arms FMI (β = 0.038, 95% CI: 0.016−0.06, p < 0.001) and legs FMI (β = 0.101, 95% CI: 0.044−0.158, p < 0.001) compared to normal sleepers, whereas no significant difference was found in long sleepers. The similar results were also observed in men, while short sleepers only had higher arms FM in women (all p < 0.01). In addition, compared to normal sleepers, short sleepers had higher arms FMI and legs FMI in the obese group (all p < 0.05), while no relationship was observed in non-obese group. Conclusions: Short sleep duration, but not long sleep duration, was independently related to the increased different regional body fat in US adults, especially in men and those with obesity.

Bioelectrical Impedance Analysis for the Assessment of Body Composition in Sarcopenia and Type 2 Diabetes

Sarcopenia is emerging as a severe complication in type 2 diabetes (T2DM). On the other hand, it has been documented that nutritional aspects, such as insufficient protein or total energy intake, increase sarcopenia risk. The analysis of body composition is a relevant approach to assess nutritional status, and different techniques are available. Among such techniques, bioelectrical impedance analysis (BIA) is particularly interesting, since it is non-invasive, simple, and less expensive than the other techniques. Therefore, we conducted a review study to analyze the studies using BIA for body composition analysis in T2DM patients with sarcopenia or at risk of catching it. Revised studies have provided important information concerning relationships between body composition parameters (mainly muscle mass) and other aspects of T2DM patients’ conditions, including different comorbidities, and information on how to avoid muscle mass deterioration. Such relevant findings suggest that BIA can be considered appropriate for body composition analysis in T2DM complicated by sarcopenia/muscle loss. The wide size of the patients’ cohort in many studies confirms that BIA is convenient for clinical applications. However, studies with a specific focus on the validation of BIA, in the peculiar population of patients with T2DM complicated by sarcopenia, should be considered.

Muscle strength and prediabetes progression and regression in middle-aged and older adults: a prospective cohort study

BACKGROUND

Prediabetes progression is associated with increased mortality while its regression decreases it. It is unclear whether muscle strength is related to prediabetes progression or regression. This study investigated the associations of muscle strength, assessed by grip strength and chair-rising time, with prediabetes progression and regression based on the China Health and Retirement Longitudinal Study (CHARLS) enrolling middle-aged and older adults.

METHODS

We included 2623 participants with prediabetes from CHARLS, who were followed up 4 years later with blood samples collected for measuring fasting plasma glucose and haemoglobin A1c. Grip strength (normalized by body weight) and chair-rising time were assessed at baseline and categorized into tertiles (low, middle, and high groups). Prediabetes at baseline and follow-up was defined primarily using the American Diabetes Association (ADA) criteria and secondarily using the World Health Organization (WHO) and International Expert Committee (IEC) criteria. Multinomial logistic regression analysis was applied to obtain the odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The mean age of included participants was 59.0 ± 8.6 years, and 46.6% of them were males. During follow-up, 1646 participants remained as prediabetes, 379 progressed to diabetes, and 598 regressed to normoglycaemia based on ADA criteria. Participants who progressed to diabetes had lower normalized grip strength than those who remained as prediabetes (0.49 ± 0.15 vs. 0.53 ± 0.15, P < 0.001), but participants who regressed to normoglycaemia showed the opposite (0.55 ± 0.16 vs. 0.53 ± 0.15, P = 0.003). However, chair-rising time was comparable across different groups (P_overall  = 0.17). Compared with participants in low normalized grip strength or high chair-rising time group, those in high normalized grip strength or low chair-rising time group had decreased odds of progression to diabetes (OR 0.62, 95% CI 0.44 to 0.87; and OR 0.69, 95% CI 0.51 to 0.93, respectively) after multivariable adjustment. However, both were unrelated to the odds of regression to normoglycaemia (OR 0.94, 95% CI 0.71 to 1.25; and OR 0.84, 95% CI 0.65 to 1.07, respectively). These outcomes remained generally comparable when prediabetes was defined by WHO or IEC criteria. Higher normalized grip strength but not lower chair-rising time was prospectively associated with lower blood pressure, better glycaemic condition, and lower inflammation (all P ≤ 0.04).

CONCLUSIONS

High muscle strength is associated with reduced odds of progression to diabetes but does not predict regression to normoglycaemia in prediabetes. Future studies are warranted to assess whether increases in muscle strength promote prediabetes regression.

Correlation of body composition in early pregnancy on gestational diabetes mellitus under different body weights before pregnancy

OBJECTIVE

The prediction of gestational diabetes mellitus (GDM) by body composition-related indicators in the first trimester was analyzed under different body mass index (BMI) values before pregnancy.

METHODS

This was a retrospective analysis of pregnant women who were treated, had documented data, and received regular perinatal care at the Third Affiliated Hospital of Zhengzhou University from January 1, 2021, to December 31, 2021. Women with singleton pregnancies who did not have diabetes before pregnancy were included. In the first trimester (before the 14th week of pregnancy), bioelectric impedance assessment (BIA) was used to analyze body composition-related indicators such as protein levels, mineral levels, fat volume, and the waist-hip fat ratio. The Pearman's correlation coefficient was used to evaluate the linear relationship between the continuous variables and pre-pregnancy body mass index (BMI). In the univariate body composition analysis, the association with the risk of developing GDM was included in a multivariate analysis using the relative risk and 95% confidence interval obtained from logarithmic binomial regression, and generalized linear regression was used for multivariate regression analysis. Furthermore, the area under the curve (AUC) was calculated by receiver operating characteristic (ROC) curves. The optimal cutoff value of each risk factor was calculated according to the Youden Index.

RESULTS

In a retrospective study consisting of 6698 pregnant women, we collected 1109 cases of gestational diabetes. Total body water (TBW), protein levels, mineral levels, bone mineral content (BMC), body fat mass (BFM), soft lean mass (SLM), fat-free mass (FMM), skeletal muscle mass (SMM), percent body fat (PBF), the waist-hip ratio (WHR), the visceral fat level (VFL), and the basal metabolic rate (BMR) were significantly higher in the GDM group than in the normal group (P<0.05). Under the pre-pregnancy BMI groupings, out of 4157 pregnant women with a BMI <24 kg/m², 456 (10.97%) were diagnosed with GDM, and out of 2541 pregnant women with a BMI ≥24 kg/m², 653 (25.70%) were diagnosed with GDM. In the generalized linear regression model, it was found that in all groups of pregnant women, pre-pregnancy BMI, age, gestational weight gain (GWG) in the first trimester, and weight at the time of the BIA had a certain risk for the onset of GDM. In Model 1, without adjusting for confounders, the body composition indicators were all positively correlated with the risk of GDM. In Model 3, total body water, protein levels, mineral levels, bone mineral content, soft lean mass, fat-free mass, skeletal muscle mass, and the basal metabolic rate were protective factors for GDM. After Model 4 was adjusted for confounders, only the waist-hip ratio was positively associated with GDM onset. Among pregnant women with a pre-pregnancy BMI <24 kg/m², the body composition-related indicators in Model 2 were all related to the onset of GDM. In Model 3, total body water, soft lean mass, fat-free mass, and the basal metabolic rate were negatively correlated with GDM onset. In the body composition analysis of among women with a pre-pregnancy BMI ≥ 24 kg/m², only Model 1 and Model 2 were found to show positive associations with GDM onset. In the prediction model, in the basic data of pregnant women, the area under the receiver operating characteristic curve predicted by gestational weight gain for GDM was the largest (0.795), and its cutoff value was 1.415 kg. In the body composition results, the area under the receiver operating characteristic curve of body fat mass for predicting GDM risk was larger (0.663) in all pregnant women.

CONCLUSIONS

Through this retrospective study, it was found that the body composition-related indicators were independently associated with the onset of GDM in both the pre-pregnancy BMI <24 kg/m² and pre-pregnancy BMI ≥24 kg/m² groups. Body fat mass, the visceral fat level, and the waist-hip ratio had a higher correlation with pre-pregnancy BMI. Total body water, protein levels, mineral levels, bone mineral content, soft lean mass, fat-free mass, skeletal muscle mass, and the basal metabolic rate were protective factors for GDM after adjusting for some confounders. In all pregnant women, the waist-hip ratio was found to be up to 4.562 times the risk of GDM development, and gestational weight gain had the best predictive power for GDM. Gestational weight gain in early pregnancy, body fat mass, and the waist-hip ratio can assess the risk of GDM in pregnant women, which can allow clinicians to predict the occurrence of GDM in pregnant women as early as possible and implement interventions to reduce adverse perinatal outcomes.