Multivariate logistic regression analysis using Model 2 with added serum insulin level and HOMA-IR also revealed an increased 0.5% risk of MetS (adjusted OR 1.005, 95% CI: 1.000–1.010, P=0.035) for every 1 pg/mL increase in FGF21 (Model 3). This evidence concerns the gene INS and metabolic syndrome.