Abstract: Objective The aim of this study was to explore the implications of serum omentin, retinol-binding protein-4 (RBP-4) and propeptide of type I procollagen (PINP) in patients with diabetes mellitus type 2 (T2DM) and non-alcoholic fatty liver diseases (NAFLD). Methods A total of 102 patients with T2DM and NAFLD (with mild steatosis in 39 cases, moderate in 34 cases and severe in 29 cases) and 98 patients with T2DM were enrolled in our hospital between June 2019 and December 2021. The hepatic steatosis was evaluated by ultrasonography, and serum omentin, RBP4 and PINP levels were detected by ELISA. The diagnostic performance was evaluated by the area under the receiver operating characteristic curve (AUC). Results Serum omentin and PINP levels in patients with T2DM and NAFLD were (45.4±12.4) ng/mL and (29.6±6.2) ng/mL, significantly lower than [(68.3±15.6) ng/mL and (35.8±7.3) ng/mL, respectively, P<0.05], while serum RBP4 level was(26.6±5.1)mg/L, significantly higher than [(20.1±4.6)mg/L, P＜0.05] in patients with T2DM; serum omentin and PINP levels in patients with severe NAFLD were (40.7±4.9)ng/mL and (25.8±3.7)ng/mL, significantly lower than [(45.2±5.6)ng/mL and (29.9±4.0)ng/mL, respectively, P＜0.05] in patients with moderate NAFLD or [(49.1±6.2)ng/mL and (32.2±3.3)ng/mL, respectively, P＜0.05] in patients with mild NAFLD, while serum RBP4 level was (30.3±3.0)mg/L, significantly higher than [(26.5±2.8)mg/L, P＜0.05] in patients with moderate NAFLD or [(23.9±3.1)mg/L, P＜0.05] in patients with mild NAFLD; the AUC was 0.856 by serum omentin, RBP4 and PINP level combination in predicting severe NAFLD in patients with T2DM and NAFLD, with the sensitivity, specificity and accuracy of 86.2%, 79.5% and 81.4%. Conclusion Serum omentin and PINP levels decrease and serum RBP4 level increase in patients with T2DM and NAFLD, which might help predicting hepatic steatosis and needs further clinical investigation.

Key words: Non-alcoholic fatty liver diseases, Type 2 diabetes mellitus, Omentin, Retinol-binding protein-4, Propeptide of type I procollagen, Diagnosis