Abstract

Objective: Obesity is characterized by increased levels of plasma free fatty acids (FFAs) that interfere with insulin signaling. The aim of our study was to assess the FFA profile in obese children and adolescents and to determine their relation with different degrees of insulin resistance. Methods: A transversal study was conducted of 51 children and adolescents (mean age, 11.7 +/- 1.6 years; 47% males) with obesity (body mass index >= 95 percentile). Anthropometric, clinical, and biochemical parameters were assessed. Insulin resistance was determined using the homeostasis model assessment of insulin resistance (HOMA-IR) index. Plasma fatty acids were quantified by high-performance liquid chromatography with heptadecanoic acid as the internal standard. Results: The mean concentration of myristic acid, linoleic acid, palmitic acid, oleic acid, stearic acid, and total fatty acids was 9.3 +/- 2.2, 86.5 +/- 38.3, 93.0 +/- 35.5, 177.0 +/- 83.6, 48.5 +/- 14.9, and 414.3 +/- 160.9 mu mol/L, respectively. Total fatty acids and unsaturated fatty acids such as oleic acid and linoleic acid showed an inverse significant correlation with insulin resistance. Children with high insulin resistance (HOMA-IR >2.5) showed a decrease in unsaturated fatty acids compared with children having a HOMA-IR of <2.5. There were no changes in saturated fatty acid concentrations between those groups. Conclusions: A decrease in unsaturated fatty acids was correlated with insulin resistance in childhood obesity.