Urinary Metabolites and Their Link with Premature Arterial Stiffness in Black Boys: The ASOS Study.

Background And Aims: Black boys (6-8 years of age) were shown to have higher pulse wave velocity with potential early vascular compromise. We aimed to compare predefined urinary metabolites in black and white boys to explore associations of pulse wave velocity with these metabolites.

Methods And Results: We included 40 white and 40 black apparently healthy boys between the ages of 6 and 8 years. Femoral pulse wave velocity was measured along with various metabolites using liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography-time of flight-mass spectrometry (GC-TOF-MS) methods. Pulse wave velocity and diastolic blood pressure were higher in the black compared to the white boys (both ≤ 0.002). Isovalerylcarnitine was lower and 1-metylhistidine tended to be lower ( = 0.002 and = 0.073, respectively), whereas L-proline levels tended to be higher ( = 0.079) in the black compared to the white boys. In single, partial, and multiple regression analyses, pulse wave velocity correlated inversely with β-alanine (β = -0.414; = 0.008) and 1-methylhistidine (β = -0.347; = 0.032) and positively with L-proline (β = 0.420; = 0.008), threonic acid (β = 0.977; = 0.033), and malonic acid (β = 0.348; = 0.030) in black boys only.

Conclusion: Our study is the first to discover the associations of pulse wave velocity with β-alanine, 1-methylhistidine, and L-proline in children from South Africa, which may suggest potential early compromise in cardiac protective metabolic pathways in black boys as young as 6 years of age.