Association between Homocysteine and Polymorphisms in MTHFR in Brazilian Obese Women

Background: Brazilian national surveys have indicated a rise in obesity and cardiovascular disease in women. Objective: To determine the frequency of 677C>T and 1 298A>C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene in obese Brazilian women and to assess the potential association of these polymorphisms with serum concentrations of homocysteine (Hcy), folate and cobalamin after fortification of wheat and corn flour with folic acid in Brazil. Methods: A cross-sectional study was conducted from 2008 to 2009 with 133 obese women. Commercial kits were employed to perform laboratory analyses including measurement of lipids and glucose using enzymatic methods, total Hcy and serum folate using a competitive immunoassay and cobalamin based on chemiluminescence. Genotyping was performed by PCR, followed by restriction fragment length polymorphism analysis. Results: The average age of participants was 39.0±4.4 years and mean body mass index was 32.5±2.1 kg/m². The distributions of the genotypes were CC (47%), CT (44%), and TT (9%) for the position MTHFR 677 and AA (60%), AC (35%), and CC (5%) for the position 1 298. Hcy levels correlated negatively with serum folate in the group displaying the 677CT, 1 298AC, or 1 298CC genotypes (r=-0.554, p<0.01). Conclusion: Our findings suggest that obese Brazilian women with genotypes 677TT have higher Hcy concentrations than those carrying the genotypes 677CT and 677CC. Additionally, genotypes 1 298CC are associated with higher Hcy concentrations than genotypes 1 298AC and 1 298AA.