Clinical significance of fasting C-peptide combined with fibrosis-4 index in assessing the progression of liver fibrosis in type 2 diabetic patients with nonalcoholic fatty liver disease

Objective To investigate the clinical significance of fasting C-peptide combined with fibrosis-4 (FIB-4) index in assessing the progression of liver fibrosis in patients with type 2 diabetes mellitus (T2 DM) and nonalcoholic fatty liver disease (NAFLD) . Methods A total of 513 patients who underwent physical examination in Physical Examination Center of China-Japan Union Hospital of Jilin University from May 2016 to July 2017 and were diagnosed with T2 DM and NAFLD were enrolled, and according to liver stiffness measurement (LSM) obtained by FibroScan, they were divided into non-progressive liver fibrosis group with 466 patients and progressive liver fibrosis group with 47 patients. Related data were recorded, including age, abdominal circumference, blood pressure, body mass index, platelet count, fasting blood glucose, fasting C-peptide, liver function, blood lipids, uric acid, and FIB-4 index. The t-test or the Mann-Whitney U test was used for comparison of continuous data between groups, and the chi-square test was used for comparison of categorical data between groups. Logistic regression was used to establish a joint diagnosis model. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of different indicators. Results Compared with the non-progressive liver fibrosis group, the progressive liver fibrosis group had significantly higher age [51 (49-55) years vs 50 (47-53) years, P = 0. 021], aspartate aminotransferase level [28. 9 (25. 7-35. 1) IU/L vs 27. 1 (22. 2-32. 8) IU/L, P = 0. 017], FIB-4 index [0. 97 (0. 75-1. 34) vs 0. 85 (0. 62-1. 19) , P = 0. 030], and fasting C-peptide level [2. 64 ± 0. 66 ng/ml vs 2. 33 ± 0. 79 ng/ml, P = 0. 004]. Fasting C-peptide (odds ratio [OR]= 1. 77, 95% confidence interval [CI]: 1. 201-2. 633, P = 0. 004) and FIB-4 index (OR = 2. 14, 95% CI: 1. 248-3. 613, P = 0. 004) were independent risk factors for progressive liver fibrosis in patients with T2 DM and NAFLD. Fasting C-peptide combined with FIB-4 index had an area under the ROC curve of 0. 730 (> 0. 70) in evaluating progressive liver fibrosis in patients with T2 DM and NAFLD. Conclusion Fasting C-peptide combined with FIB-4 index has a certain value in the diagnosis of progressive liver fibrosis in patients withT2 DM and NAFLD.