Association between Body Fat Composition and Serum Branched Chain Amino Acids in Obese Patients

Objective: This study investigated the correlation between serum branched-chain amino acids (BCAAs) and body fat composition—specifically visceral fat—in obese individuals and assessed their association with insulin resistance (IR). Methods: A total of 105 participants were enrolled and divided into three groups. The groups were as follows: obese individuals without type 2 diabetes mellitus (T2DM) (n=52), obese individuals with T2DM (n=32), and healthy controls (n=21). Anthropometric indices, biochemical parameters, and serum amino acid profiles were assessed. Associations were examined using correlation analyses and multiple linear regression. . Results: Serum BCAA levels remained drastically higher in both obese groups than in controls (p < 0.001). Valine showed the greatest increase (obese non-T2DM: 35.98±8.29 µg/mL; obese T2DM: 42.40±8.37 µg/mL; controls: 30.48±4.19 µg/mL). BCAAs were positively associated with visceral fat area (VFA), body mass index (BMI), body fat ratio, and IR-related markers (HOMA-IR, fasting insulin, and HbA1c) (all p<0.05). Valine demonstrated the strongest correlations with HOMA-IR (r=0.431, p<0.001) and VFA (r=0.445, p<0.001). Strong positive correlations were also observed between BCAAs and fasting glucose, fasting insulin, HbA1c, and lipid parameters. In multivariable models, free amino acids were independently associated with total body fat, whereas overall BCAA levels were not independent predictors of total body fat. Conclusion: Obesity is characterized by altered amino acid metabolism, which may contribute to metabolic complications. Elevated circulating BCAAs, particularly valine, are associated with visceral adiposity and insulin resistance and may represent biomarkers of metabolic risk in obesity. Clinical trial number: Not applicable