Amino Acid Signature in Urine is Associated With Cardiovascular Risk in Brazilian Children

Abstract

Childhood obesity is a complex multifactorial disease that contributes to higher cardiometabolic risk. Other important parameter is the pattern of fat distribution, even among normal weight children, those with central fat deposition show higher cardiovascular risk. The waist to height ratio (WHtR) is a useful and practical tool to assess central obesity and cardiovascular risk. Childhood obesity is associated with metabolic abnormalities which are mechanisms underlying cardiovascular diseases. The metabolomics can detect biomarkers for exposure, disease progression and susceptibility contributing to early intervention strategies. In this cross-sectional study it was evaluated the profile of amino acids in urine of children with different cardiovascular risk status according to WHtR. The 110 participants aged from 9 to 10 years were classified according to WHtR into the groups: high cardiovascular risk (n = 48) and normal cardiovascular risk (n = 62). The 24 hours urine samples were collected, and aliquots submitted to LC–MS/MS for evaluation of 47 amino acids using the Amino Acids Analysis Kit (Zivak®, Turkey), values were corrected by creatinine. 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 from high cardiovascular risk group, cystathionine (25 vs 21 nmol/mg of creatinine, p = 0.03), Lys (212 vs 160, p < 0.01) and the aromatic amino acids Tyr (131 vs 90, p < 0.01), Trp (109 vs 95, p =0.02) and Phe (65 vs 46, p = 0.04). Linear regression identified that cystathionine, Lys, Tyr, Trp and Phe presented weak but significant positive correlation with anthropometric measurements. Cystathionine, Trp and Lys negatively correlates with HDL while Phe and Tyr positively correlated with triglycerides. Also, Lys and Tyr were positively associated with higher systolic blood pressure. Findings corroborate to literature and indicate that there is a signature profile of amino acids in urine of children with increased cardiovascular risk associated to central obesity. The augmented Tyr and Lys may be the most significant markers once they were also associated to higher SBP.