High fasting insulin concentrations may be a pivotal predictor for the severity of hepatic fibrosis beyond the glycemic status in non‐alcoholic fatty liver disease patients before development of diabetes mellitus

Background Insulin resistance and type 2 diabetes mellitus (T2DM) contribute to the progression of nonalcoholic fatty liver disease (NAFLD). However, the relationship between glucose metabolic factors and the histological severity in NAFLD patients before development of T2DM is not well known. Methods In 103 biopsy-proven NAFLD patients (68 males and 35 females) with HbA1c of <6.5% and fasting blood glucose of <126 mg/dl, we investigated whether glucose metabolic factors influenced the severity of hepatic fibrosis without prior known T2DM. Results Female gender, age, AST, the AST/ALT ratio, f-IRI, HOMA-IR, HbA1c, hyaluronic acid, and type IV collagen 7s were significantly higher and 1,5-AG was significantly lower in the F3 group than in the F0–2 group. Multiple logistic regression analysis showed that only f-IRI (p = 0.006; odds ratio [OR]: 1.15151; 95% confidence interval: 1.04198–1.27254) was significantly indicated as a predictive factor for F3. As determined by both forward and backward stepwise selection analyses to optimize the model, f-IRI (p = 0001; OR: 1.16788) remained as independent predictive factor for F3. To discriminate the F3 group from the F0–2 group, the area under the receiver operating characteristic (ROC) curves showed that fasting insulin was 0.7219, and the best cutoff value of f-IRI was 13.2 μU/ml in ROC analysis. Conclusions High fasting insulin concentrations may be a pivotal glucose metabolic predictor for the severity of hepatic fibrosis beyond the glycemic status in NAFLD patients before development of T2DM.