In the Spearman rank correlation test, the serum irisin of VD patients was significantly negatively correlated with age (r = −0.231, p < 0.001), gender (r = −0.174, p = 0.005), BMI (r = −0.159, p < 0.001), SBP (r = −0.254, p < 0.001), DBP (r = −0.217, p < 0.001), TC (r = −0.322, p = 0.013), TG (r = −0.283, p < 0.001), LDL-C (r = −0.195, p < 0.001) and FBG (r = −0.170. This evidence concerns the gene FNDC5 and sexually transmitted disease.