UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

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

Overweight and moderate obesity confer a survival benefit in chronic diseases such as coronary artery disease and chronic kidney disease, which has been termed the \"obesity paradox\". However, whether this phenomenon exists in trauma patients remains controversial. We performed a retrospective cohort study in abdominal trauma patients admitted to a Level I trauma center in Nanjing, China between 2010 and 2020. In addition to the traditional body mass index (BMI) based measures, we further examined the association between body composition-based indices with clinical severity in trauma populations. Body composition indices including skeletal muscle index (SMI), fat tissue index (FTI), and total fat-to-muscle ratio (FTI/SMI) were measured using computed tomography. Our study found that overweight was associated with a four-fold risk of mortality (OR, 4.47 [95% CI, 1.40-14.97], p = 0.012) and obesity was associated with a seven-fold risk of mortality (OR, 6.56 [95% CI, 1.07-36.57], p = 0.032) compared to normal weight. Patients with high FTI/SMI had a three-fold risk of mortality (OR, 3.06 [95% CI, 1.08-10.16], p = 0.046) and double the risk of an intensive care unit length of stay ≥ 5 d (OR, 1.75 [95% CI, 1.06-2.91], p = 0.031) compared to patients with low FTI/SMI. The obesity paradox was not observed in abdominal trauma patients, and high FTI/SMI ratio was independently associated with increased clinical severity.

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.

BACKGROUND: Although dyslipidaemia may have a crucial impact on cardiovascular health in adults, there is a lack of specific data in transitional-age youth. Therefore, this study attempted to evaluate the association of dyslipidaemia with fat-to-muscle ratio (FMR), and establish FMR thresholds for diagnosing dyslipidaemia in transitional-age youth.
METHODS: One thousand six hundred sixty individuals aged 16 to 24 years from the baseline of a subcohort in the Northwest China Natural Population Cohort: Ningxia Project were analysed. Anthropometric characteristics were gauged by a bioelectrical impedance analyser, and dyslipidaemia components were measured using a Beckman AU480 chemistry analyser. Additionally, this study used logistic regression to estimate the risk of dyslipidaemia based on FMR quintiles, and calculate the gender-specific ideal cut-off values of dyslipidaemia and its components by the receiver operating characteristic (ROC) curve.
RESULTS: Of the 1660 participants, aged 19.06 ± 1.14 years, 558 males and 1102 females. The prevalence of dyslipidaemia was 13.4% and was significantly associated with FMR quintiles among all participants (P < 0.05). The ideal values of FMR in diagnosing dyslipidaemia were 0.2224 for males and 0.4809 for females, while males had a higher AUC than females (0.7118 vs. 0.6656). Meanwhile, high FMR values were significantly associated with adverse outcomes of dyslipidaemia, hypercholesterolemia and hypertriglyceridaemia (P < 0.05).
CONCLUSIONS: The FMR was positively correlated with the prevalence of dyslipidaemia. The FMR can be used as an effective body composition index for diagnosing dyslipidaemia, especially in males, and preventive strategies should be initiated in transitional-age youth to decrease obesity-related dyslipidaemia.

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.
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.
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.
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.

UNASSIGNED: Age-related muscle mass and function decline are critical issues that have gained attention in clinical practice and research. Nevertheless, little is known regarding the time course of muscle health progression, and its determinants during this transition should be estimated.
UNASSIGNED: We enrolled community-dwelling adults aged ≥65 years during their regular health checkup. The participants\' body composition and muscle function were measured annually from 2015 to 2021. Presarcopenia was characterized by the loss of muscle mass only; dynapenia was defined as low muscle function without changes in muscle mass; and sarcopenia was indicated as a decline in both muscle mass and muscle function. We observed the natural course of muscle health progression during aging. The relationship between muscle health decline and different determinants among old adults was examined.
UNASSIGNED: Among 568 participants, there was 18.49%, 3.52%, and 1.06% of healthy individuals transited to dynapenia, presarcopenia, and sarcopenia, respectively. Significant positive correlations between age, fat-to-muscle ratio (FMR) and the dynapenia transition were existed [hazard ratio (HR) = 1.08 and HR = 1.73, all p < 0.05]. Serum albumin level had negative correlation with the dynapenia transition risk (HR = 0.30, p = 0.004). Participants with these three risk factors had the highest HR of dynapenia transition compared to those without (HR = 8.67, p = 0.001). A dose-response effect existed between risk factors numbers and the risk of dynapenia transition (p for trend < 0.001). This positive association and dose-response relationship remains after multiple covariates adjustment (HR = 7.74, p = 0.002, p for trend < 0.001). Participants with two or more than two risk factors had a higher risk of dynapenia transition than those with low risk factors (p = 0.0027), and the HR was 1.96 after multiple covariate adjustment (p = 0.029).
UNASSIGNED: Healthy community-dwelling old adults tended to transit to dynapenia during muscle health deterioration. Individuals with older age, higher FMR, lower albumin level had a higher risk of dynapenia transition; and a positive dose-response effect existed among this population as well.

BACKGROUND: Altered body composition is known to be related to abnormal metabolism. The aim of this study was to determine the association between the fat-to-muscle ratio (FMR) and metabolic disorders in type 2 diabetes (T2DM) population.
METHODS: In total, 361 T2DM participants aged ≥ 18 years were included in our research. A bioelectrical impedance analyzer was applied to measure fat mass and muscle mass. FMR was calculated as body fat mass (kg) divided by muscle mass (kg). The performance of FMR to assess metabolic disorders in T2DM was conducted using ROC curves. The independent association between FMR and metabolic syndrome (MS) was tested by logistic regression analysis.
RESULTS: The FMR was significantly higher in patients with MS than in those without MS (p < 0.001). The optimal FMR cutoff point for identifying MS was higher in females than in males (0.465 vs. 0.296, respectively). In addition, the areas under the ROC curve (AUCs) for the evaluation of MS by FMR, fat mass, muscle mass, BMI and waist circumference were further compared, indicating that the AUC of FMR (0.843) was the largest among the five variables in females, but the AUC of waist circumference (0.837) was still the largest among other variables in males. Based on the derived FMR cutoff point, patients with a high FMR exhibited more cardiometabolic risk indicators (all p < 0.05). Using a low FMR as a reference, the relative risk of a high FMR for MS was 2.861 (95% CI 1.111-7.368, p = 0.029) in males and 9.518 (95% CI 2.615-34.638, p = 0.001) in females following adjustment for confounding factors.
CONCLUSIONS: The fat-to-muscle ratio is independently and positively associated with metabolic disorders in T2DM. FMR may serve as an optimal method for screening T2DM patients coupled with a high risk of abnormal metabolism, especially in females, providing a new perspective for the prevention and treatment of cardiovascular complications in Chinese type 2 diabetes.

Maintaining optimal low-density lipoprotein (LDL) cholesterol levels is necessary to prevent cardiovascular disease (CVD). Excessive fat mass and decreased muscle mass are both associated with increased risks of developing dyslipidemia. Thus, we investigated the longitudinal relationship between the fat-to-muscle ratio (FMR) and the non-achievement of LDL cholesterol targets. We analyzed a total of 4386 participants aged 40-69 years from the Korean Genome and Epidemiology Study. FMR was defined as the ratio of total fat mass to total muscle mass, measured by bioelectrical impedance. The non-achievement of an LDL cholesterol target was defined as an LDL cholesterol level higher than the established target level according to individual CVD risk. The adjusted hazard ratios and 95% confidence interval for the incidence of non-achievement of LDL cholesterol targets for the sex-specific middle and highest tertiles vs. the referent lowest tertile of FMR were 1.56 (1.29-1.90) and 1.86 (1.47-2.31) in men and 1.40 (1.18-1.66) and 1.31 (1.06-1.62) in women after adjusting confounders. Our findings suggest that FMR, a novel indicator of the combined effects of fat and muscle mass, is useful for predicting non-achievement of LDL cholesterol targets.

UNASSIGNED: Insulin resistance (IR) assessment is important in treating type 2 diabetes mellitus (T2DM). We thus compared body muscle-to-fat ratio (BMFR) and fat-to-muscle ratio (FMR) values against M/I values as clinical index of IR.
UNASSIGNED: Subject included 118 untreated T2DM patients. Hyperinsulinemic-euglycemic clamp examination was performed to calculate the M/I as index of IR. Body composition was measured by impedance analysis using InBody770.
UNASSIGNED: Simple linear regression analyses confirmed correlations between M/I and BMFR (B: 0.756 (P < 0.01), coefficients of determination (R2): 0.572, mean absolute error (MAE): 3.19, and root mean squared error (RMSE): 4.14), and between M/I and FMR (B: -0.601 (P < 0.01), R2: 0.362, MAE: 3.97, and RMSE: 5.05). Against the M/I values, BMFR also showed better goodness-of-fit than did FMR. In comparing correlation coefficients, the BMFR absolute B value was significantly larger than that of FMR (P = 0.027).
UNASSIGNED: BMFR is more useful than FMR in quantifying IR in patients with T2DM because the correlation between BMFR and the insulin sensitivity index M/I is significantly greater than that between FMR and M/I.