Neither YKL-40 nor MCP-1 correlated significantly with BMI, WHR, triglyceride, FFA, HbA1c, or HOMA-IR preoperatively (type 2 diabetes: P values = 0.063 − 0.996; NGT: P values = 0.063 − 0.944) or at 1 yr after the operation (type 2 diabetes: P values = 0.160 − 0.980; NGT: P values 0.081 − 0.916) in gender and age adjusted linear regression models when adjusting a.m. Bonferroni. Here, CCL2 is linked to type 2 diabetes mellitus.