Serum Cortistatin Level in Type 2 Diabetes Mellitus and Its Relationship with Nonalcoholic Fatty Liver Disease

PURPOSE: To evaluate serum cortistatin (CST) levels in type 2 diabetes mellitus (T2DM) patients with or without non-alcoholic fatty liver disease (NAFLD) and to examine the relationship between CST and NAFLD. METHODS: A total of 90 T2DM patients, which included 56 NAFLD patients (referred to as DM+NAFLD group) and 34 patients without NAFLD (DM-only group), and 83 non-diabetes individuals that included 39 NAFLD patients (NAFLD-only group) and 44 without NAFLD that acted as the normal-control group (NC group). The differences in the serum CST levels between the groups were compared, and the correlations between CST and other variables were calculated by applying both correlational analysis and multiple linear regression analysis. RESULTS: The mean serum CST levels were significantly lower in the DM+NAFLD and DM groups than in the NC group (P < 0.05). In addition, the CST levels were lower in the DM group relative to that in the NAFLD group (P < 0.05). However, no statistical difference was noted in the serum CST between diabetic patients with and without NAFLD (P > 0.05). Similarly, in the non-diabetic group, the serum CST level was not significantly different between individuals with and without NAFLD (P > 0.05). Furthermore, the serum CST levels were negatively associated with the levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), fasting plasma glucose (FPG), homeostasis model assessment-insulin resistance (HOMA-IR), and insulin cell function index (HOMA-β). Conversely, the serum CST levels were positively associated with high-density lipoprotein cholesterol (HDL-C). The data obtained through multiple linear regression implied that LDL-C and HOMA-β, but not HOMA-IR, were closely related to serum CST levels. CONCLUSION: T2DM was related to decreased serum CST. However, serum CST was correlated with HOMA-β in T2DM patients, while HOMA-IR was not. There was no correlation between CST and NAFLD.