Analysis and correlation of urinary amino acids and nutritional status in Brazilian children

Abstract

Impairment in metabolic pathways is associated with cardiometabolic diseases such as obesity, diabetes and cardiovascular diseases. Obesity, for instance, is a multifactorial disease that is linked to physical, social, psychological and economic burdens being characterized as a health public problem. Childhood obesity is tightly related with obesity and cardiovascular problems in adulthood. Inadequate diet and lifestyle in early childhood can contribute to alterations in the metabolites levels and development of childhood obesity and associated diseases. In this cross-sectional study it was evaluated the profile of amino acids in urine of 110 children that were classified in into three groups of nutritional status according to their BMI (Body Mass Index), as normal weight (NW) (n=46), overweight (OW) (n=22) and obese (OB) (n=45). The 24 hours urine samples were submitted to LC–MS/MS for evaluation of 47 amino acids using the Amino Acids Analysis Kit (Zivak®, Turkey), values were corrected by creatinine concentration. Biochemical profile, cardiovascular parameters and anthropometric measurements were assessed following standard protocols. The following amino acids were found in higher concentrations in urine of children with overweight or obesity, when compared with normal weight group, glutamine (NW: 1024.3 vs OW: 1309.2 nmol/mg of creatinine, p=0.05), tryptophan (NW: 85.65, OW:113.55, OB:109.36 nmol/mg of creatinine; NW vs OW p=0.01; OW vs OB p=0.004), phenylalanine (NW: 43.04, OW:49.66, OB:72.08 nmol/mg of creatinine; NW vs OB p=0.01; OW vs OB p=0.04), Tyrosine (NW: 85.07, OW: 109.74, OB: 140.54 nmol/mg of creatinine; NW vs OB p<0.01; OW vs OB p=0.04).In addition, sarcosine showed reduced concentrations for obese participants (OW: 78.7 vs OB: 62.3, p=0.04). The urine levels of glutamine and of the aromatic amino acids were influenced by nutritional status being higher in OW and OB children. Interestingly, the tryptophan showed a positive correlation with the BMI of the participant's mother. Also, tryptophan andtyrosine were negatively correlated with HDL, while phenylalanine and tyrosine hada positive correlation with triglycerides levels. Tyrosine also showed a positive association with systolic blood pressure values. In our results, the correlation between the concentrations of the aromatic amino acids and the increase in children's obesity levels stands out, and this corroborates with the literature data and can represent markers of obesity.