Correlations of serum 25-hydroxyvitamin D₃ with glucose metabolism, liver function and disease progression of patients with type 2 diabetes mellitus complicated with nonalcoholic fatty liver disease

  Objective  To investigate the correlations of serum 25-hydroxyvitamin D₃ 25-(OH)-D₃ with glucose metabolism, liver function and disease progression in patients with type 2 diabetes mellitus (T2DM) complicated with nonalcoholic fatty liver disease (NAFLD).

  Methods  A total of 128 T2DM patients were enrolled as subjects and divided into T2DM group (n=41) and NAFLD group (n=87) according to whether they had NAFLD or not, and 50 healthy subjects were enrolled as control group. NAFLD group was divided into group A (good blood glucose control), group B (general blood glucose control) and group C (poor blood glucose control) according to the blood glucose control status. According to the NALFD Fibrosis Score (NFS), patients were divided into NFS>0.676 group, NFS -1.455 to 0.676 group and NFS < -1.455 group. The correlation between serum 25-(OH)-D₃ level and glucose metabolism as well as liver function in NAFLD patients were analyzed.

  Results  The levels of triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and serum 25-(OH)-D₃ in the control group, the T2DM group and the NAFLD group showed significant differences (P < 0.05). Hemoglobin A1c (HbA1c), fasting plasma glucose(FPG), 2-hour plasma glucose (2 hPG), homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of-β cell function (HOMA-β) of NAFLD patients with different blood glucose control levels had statistical differences (P < 0.05). Correlation analysis showed that serum 25-(OH)-D₃ level was positively correlated with HOMA-β in NAFLD patients (P < 0.05); there were significant differences in alanine aminotransferase (ALT) and serum 25-(OH)-D₃ levels among patients with different NFS scores (P < 0.05). Correlation analysis showed that ALT level was positively correlated with serum 25-(OH)-D₃ level in NAFLD patients (P < 0.05).

  Conclusion  The serum levels of 25-(OH)-D₃ in patients with T2DM and NAFLD are positively correlated with the levels of HOMA-β and ALT, suggesting that vitamin D deficiency may cause poor blood glucose control and promote the progression of liver fibrosis. In addition, detection of serum 25-(OH)-D₃ level also provides a reliable channel for monitoring liver function and fibrosis in NAFLD patients.