Aim/hypothesis: Leucine, isoleucine and valine are branched chain amino acids (BCAA). BCAAs areamong the 9 essential amino acids and are associated with beneficial health effects. However, previous studies have reported strong associations between increased BCAA levels, obesity and metabolic diseases such as type 2 diabetes. The objective of this study is to investigate the association between plasma BCAA levels, cardiometabolic risk factors and Metabolic Syndrome (MetS) in normal versus overweight/obese subjects. Methods: Mass spectrometry-based metabolite profiling of 200 samples using the Absolute ID p180 Kit was used to compare plasma BCAA levels between overweight/obese subjects with or without MetS and normal weight subjects without MetS. Results: Overweight/obese participants irrespective of their MetS status have higher plasma BCAA levels than normal weight participants (P< 0.0001). Obesity-associated MetS appears to worsen the difference with normal weight subjects. Leucine (P= 0.005) and isoleucine (P= 0.02) levels are correlated with HOMA-IR among obese individuals without MetS. Among obese subjects with MetSleucine levels (P= 0.04) are correlated to HOMA-IR whereas leucine and isoleucine are correlated with plasma glucose levels. Conclusions/interpretation: BCAAs are associated with obesity and MetS. Also, these results suggest that analyzing BCAAs separately may help for a better understanding of the association between BCAAs obesity and Mets.

Abbreviations: BCAA: Branched Chain Amino Acid; CVD: Cardio Vascular Disease; DBP: Diastolic Blood Pressure; IR: Insulin Resistance; MetS: Metabolic Syndrome; SBP: Systolic Blood Pressure; Total-C: Total Cholesterol; Tg: Triglycerides; T2D: Type 2 Diabetes; WC: Waist Circumference