Plasminogen activator inhibitor-1 4G/5G and the MTHFR 677C/T polymorphisms and susceptibility to polycystic ovary syndrome: A meta-analysis

The aim of this study was to explore whether the plasminogen activator inhibitor-1 (PAI-1) 4G/5G and the methylenetetrahydrofolate reductase (MTHFR) 677C/T polymorphisms are associated with susceptibility to polycystic ovary syndrome (PCOS). Meta-analyses were conducted to determine the association between the PAI-1 4G/5G and MTHFR 677C/T polymorphisms and PCOS using: (1) allele contrast (2) homozygote contrast, (3) recessive, and (4) dominant models. For meta-analysis, nine studies of the PAI-1 4G/5G polymorphism with 2384 subjects (PCOS, 1615; controls, 769) and eight studies of the MTHFR 677C/T polymorphism with 1270 study subjects were included. Meta-analysis of all study subjects showed no association between PCOS and the PAI-1 4G allele (OR = 0.949, 95% CI = 0.671-1.343, p = 0.767). Stratification by ethnicity, however, indicated a significant association between the PAI-1 4G allele and PCOS in Turkish and Asian populations (OR = 0.776, 95% CI = 0.602-0.999, p = 0.049; OR = 1.749, 95% CI = 1.297-2.359, p = 2.5 × 10^-5 respectively). In addition, meta-analysis indicated an association between PCOS and the PAI-1 4G4G + 4G5G genotype in Europeans (OR = 1.406, 95% CI = 1.025-1.928, p = 0.035). However, meta-analysis of all study subjects showed no association between PCOS and the MTHFR 677T allele (OR = 0.998, 95% CI = 0.762-1.307, p = 0.989), including Europeans (OR = 0.806, 95% CI = 0.610-1.063, p = 0.126). Meta-analysis showed no association between PCOS and the MTHFR 677C/T polymorphism using homozygote contrast, and recessive and dominant models. In conclusion, meta-analysis suggests the PAI-1 4G/5G polymorphism is associated with susceptibility to PCOS in European, Turkish, and Asian populations, but the MTHFR 677C/T polymorphism is not associated with susceptibility to PCOS in Europeans.