Genetic polymorphism of methylenetetrahydrofolate reductase is associated with insulin resistance in Egyptian women with polycystic ovary syndrome

Background A common polymorphism (677C to T; Ala to Val) in the methylenetetrahydrofolate reductase (MTHFR) gene is associated with decreased specific MTHFR activity and elevation of homocysteine. The present study aimed to investigate the association between a single nucleotide polymorphism (SNP) in the MTHFR 677C>T gene and insulin resistance in women with polycystic ovary syndrome (PCOS). Methods Two-hundred patients with PCOS were included in this case-control study: 100 patients with insulin resistance and 100 patients without insulin resistance were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis. Results The TT genotype for the MTHFR 677C>T polymorphism was significantly more frequent in PCOS patients with insulin resistance than in PCOS patients without insulin resistance (19% versus 6%, p = 0.002), whereas there was no significant difference between both groups for CT and there was a statistically significant increase in the T allele in PCOS patients with insulin resistance compared to PCOS patients without insulin resistance (p = 0.002, odds ratio = 1.95 and 95% confidence interval = 1. 29-2.93). Regarding the relationship between MTHFR 677C>T genotypes and the characteristics of insulin resistance in PCOS patients, we found that there was no significant difference in age, waist-hip ratio and total testosterone between the different genotypes of the MTHFR 677C>T polymorphism. The mean values for body mass index and the Homeostatic Model Assessment of Insulin Resistance were significantly higher in the TT genotype of MTHFR 677C>T compared to the CC genotype in PCOS patients with insulin resistance (p < 0.001). Conclusions We have demonstrated an association of the MTHFR 677C>T gene polymorphism with insulin resistance in Egyptian women with PCOS.