ABSTRACT
AIM: The aim of this study was to investigate possible relationships among the A1298C (rs1801131) and C677T (rs1801133) polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and levels of homocysteine, vitamins B6, B12, folic acid and lipid profile, including oxidized low-density lipoprotein (ox-LDL), of adolescents at cardiovascular risk. METHODS: We recruited 115 adolescents (10-19 years old), 58.3% (n = 67) female, from a public school in Brazil who underwent anthropometric, biochemical and genetic tests as well as food consumption evaluation. RESULTS: An important prevalence of hyperhomocysteinemia (19.1%) and alterations in triacylglycerol (17.4%), total cholesterol (26.9%) and high-density lipoprotein (HDL) cholesterol (48.0%) concentrations were observed, as well as low vitamin B6 concentrations (23.5%). The categorization of homocysteine concentrations into tertiles revealed significant differences in serum concentrations of folate, vitamin B12 and HDL, waist circumference and intake of total and saturated fat among the tertiles. The presence of variant alleles regarding the MTHFR C677T polymorphism interfered with vitamin B6 and ox-LDL cholesterol concentrations. There was a trend for higher waist circumference values in T carriers (C677T), but not in C carriers (A1298C). CONCLUSIONS: The MTHFR C677T allele was associated with higher plasma vitamin B6 and ox-LDL compared to the CC genotype.