According to unadjusted logistic regression analysis, an increased risk of metabolic syndrome was associated with PAI-1 alleles ‘GA/5G5G’ (rs2227631/rs1799889), ‘GA/GG’ (rs2227631/rs6092), ‘AA/GA’ (rs2227631/rs2227694) and ‘GA/AA’ (rs2227631/rs1050955). The gene discussed is SERPINE1; the disease is metabolic syndrome.