Background: Hyperhomocysteinemia is a potential risk factor for the development of metabolic syndrome (MetS). Among genes involved in homocysteine metabolism, polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene are known to be associated with MetS incidence. However, effects of polymorphisms of other folate metabolism-related genes on MetS susceptibility are not well known yet.
Objective: This study was to determine whether methionine synthase (MTR) 2756A > G, methionine synthase reductase (MTRR) 66A > G, and thymidylate synthase enhancer region (TSER) 2R/3R polymorphisms might be associated with risks of MetS development in the Korean population.
Methods: Genotype analysis of the three polymorphisms was performed for a total of 483 subjects including 236 MetS patients and 247 unrelated healthy controls using polymerase chain reaction-restriction fragment length polymorphism technique.
Results: The present study revealed that MTRR and TSER polymorphisms were associated with susceptibility to MetS. Several genotypes and allele combinations from the three polymorphisms were also related to the MetS prevalence. When polymorphism data were stratified according to the risk components of MetS, MTR polymorphism was significantly associated with an increased risk of MetS in subjects with systolic blood pressure < 132.7 mmHg (AOR 1.842, 95% CI 1.039-3.266, P = 0.037) and fasting blood glucose level < 106.3 mg/dL (AOR 1.772, 95% CI 1.069-2.937, P = 0.027). MTRR polymorphism was significantly associated with a decreased risk of MetS in subjects with triglyceride level < 216.3 mg/dL (AOR 0.616, 95% CI 0.399-0.951, P = 0.029). To the best of our knowledge, this is the first to provide reliable evidence about the association of other folate metabolism-related gene polymorphisms besides MTHFR with MetS susceptibility and its risk factors.
Conclusion: Results of this study suggest that MTRR and TSER polymorphisms might be potential genetic markers for the risk of MetS development in Korean population.
Keywords: Association; MTR; MTRR; Metabolic syndrome; Polymorphism; TSER.