Plasma Amino Acid Levels in Obese Adolescents: A Case-Control Study and the Review of the Literature

Optimal balance among amino acids in the circulation is important for body homeostasis. This study aims to evaluate and define the amino acids associated with obesity and insulin resistance. Fifty obese and 42 healthy adolescents aged 10-18 years were included in this study. Fasting plasma glucose, liver enzymes, thyroid function tests, insulin, and lipid levels were studied as routine laboratory examinations, and 26 plasma amino acids were studied as specific laboratory examinations. Isoleucine, leucine, lysine, tryptophan, glutamate, tyrosine, phenylalanine, alanine, methionine, argininosuccinic acid, histidine and valine were significantly higher in patients with obesity. Asparagine and citrulline levels were lower in patients with insulin resistance. The metabolic pathways of various amino acids are significantly impaired in obesity. Plasma concentrations of essential, non-essential, branchedchain, and aromatic amino acids were elevated in this study.