Elevated serum eNAMPT levels were found in RA patients compared with healthy controls (P = 0.000). In addition, eNAMPT concentrations positively correlated with insulin (r = 0.303, P = 0.05), HOMA-IR (r = 0.346, P = 0.029), HOMA-B (r = 0.434, P = 0.005), cholesterol (r = 0.501, P = 0.001), TG (r = 0.471, P = 0.002), LDL-C (r = 0.319, P = 0.045), and the disease activity score (DAS moderate: r = 0.329, P = 0.038; DAS severe > 5: r = 0.528, P = 0.003). A negative correlation was also found between eNAMPT levels and HDL-C (r = −0.398, P = 0.011) and adiponectin (r = −0.686, P = 0.000). This evidence concerns the gene INS and rheumatoid arthritis.