The role of adipose tissue in liver fat accumulation: a sex-specific analysis in an exploratory cross-sectional study.

INTRODUCTION

Visceral (VAT), subcutaneous (SFT), and total body fat (FM) contribute to hepatic steatosis, yet their relative and sex-specific effects across total, regional, and site-specific levels remain unclear. We investigated associations between fat depots, standardized skinfold sites, and liver fat (LF) while adjusting for key metabolic covariates.

METHODS

In this secondary data analysis of a cross-sectional study, 48 adults (50% women; 49.6 ± 20.9 y; BMI 25.7 ± 3.7 kg/m²) underwent quantitative MRI to assess VAT and LF and ultrasound-based body mapping to quantify total and regional SFT as well as standardized skinfold sites. Bioelectrical impedance analysis determined FM. Regression analyses were conducted with LF as the dependent variable, identifying and controlling for significant covariates (diabetes mellitus [DM], arterial hypertension [aHT], hypercholesterolemia [HC], physical activity, age) (partial r). The Lindeman-Merenda-Gold (LMG) method decomposed total R² into fat-specific contributions. Total fat depots were adjusted for body surface area (BSA).

RESULTS

All regression models examining associations with LF showed total r values ranging from 0.63 to 0.79. In men, DM was the only significant covariate (p = 0.002). Values are given as: partial r, LMG share (% of R2). LF correlated with VAT/BSA (0.40, 51%), total SFT/BSA (0.38, 42%), and FM/BSA (0.36, 51%). Regionally, upper-body SFT (0.40, 45%) and SFT_arms (0.37, 47%) contributed most, whereas lower-body SFT (0.35, 13%) showed minimal impact. The triceps skinfold was the most influential site among skinfolds (0.45, 50%). In women, HC was the only significant covariate (p = 0.02). LF correlated with VAT/BSA (0.40, 49%), total SFT/BSA (0.51, 27%), and FM/BSA (0.47, 36%). Regional models yielded upper-body SFT (0.43, 36%), SFT_arms (0.38, 23%), and lower-body SFT (0.41, 9%). Among single sites, the umbilical skinfold was most relevant (0.43, 36%), followed by the biceps (0.42, 33%).

CONCLUSION

VAT remains pivotal for LF in both sexes, yet SFT exhibits clear sex- and region-specific relevance. Only subcutaneous fat of the upper-body and arms contributed meaningfully to liver fat. Simple skinfold assessments-particularly triceps in men-may serve as practical indicator for early risk stratification. Larger, prospective cohorts are needed to confirm these findings.

TRIAL REGISTRATION: Not applicable this study did not involve any health care intervention.