The Complex Relation of Branched-Chain Amino Acids and Inflammation in the Obesity and Diabetes Context

In a scenario with increasing cases of obesity and diabetes worldwide, branched-chain amino acids (BCAA) metabolism has become an important factor in the understanding of these pathologies. More recently, its chronic high plasma levels have been postulated, alongside glucose, inflammatory factors, and other molecules, as an important predictive marker for developing insulin resistance. High-fat diet protocols and models mimicking obesity and type-2 diabetes have clarified our knowledge about how these conditions, which have an important inflammatory aspect, impact the BCAA catabolism in several tissues and its systemic effects. On the other hand, BCAA supplementation has been studied in several experimental models aiming to understand its role in inflammation. Evidence reveals that a chronic low-grade inflammatory state is an important factor in several age-related pathological conditions and that its presence, characterized by augmented proinflammatory cytokines, high glucose and BCAA levels, would be a determining factor. Although, the relationship between BCAA and inflammation is complex and our current knowledge cannot identify a causative role for these amino acids, as in the majority of the cases a previous or concomitant stimulus was necessary to demonstrate their role in the modulation of inflammation.