Interactions between lifestyle and MTHFR polymorphisms on homocysteine concentrations in young adults belonging to the 1982 Pelotas Birth Cohort

Background/Objectives: Homocysteine (Hcy) is a key intermediate in methionine metabolism. A high plasma concentration of Hcy is an independent risk factor for cardiovascular diseases among other determinants. In this study, we aimed to investigate the interactions between methylenetetrahydrofolate reductase enzyme gene (MTHFR) polymorphisms and lifestyle variables (smoking, alcohol intake and physical activity) on Hcy concentrations in a young Brazilian population. Subjects/Methods: The study population comprised 3803 individuals from the Pelotas Birth Cohort, aged 22–23 years. Allelic discrimination assays and chemiluminescence immunoassays were performed for genotyping and serum Hcy measurements, respectively. Linear regression models were used to explore the effect of gene–lifestyle interactions on Hcy concentrations. Results: Men carrying the MTHFR 677TT genotype, who were also smokers and drinkers (⩾15 g of alcohol per day), had the highest concentration of Hcy ( P -value for the interaction