Prevalence of Insulin Resistance in Subjects with Nonalcoholic Fatty Liver Disease and Its Predictors in a Chinese Population

Insulin resistance (IR) is a key factor involved in the development and progression of nonalcoholic fatty liver disease (NAFLD). However, the prevalence of IR in NAFLD patients and its risk factors have been rarely reported, especially in China. This prospective study was undertaken to clarify these issues in the Chinese population. A total of 600 NAFLD patients and 300 age- and sex-matched healthy controls were recruited between January 1, 2011, and December 31, 2013. Demographic information and clinical characteristics were collected, and the presence of IR was evaluated using the homeostasis model. Uni- and multivariate analyses were conducted, and receiver operating characteristic (ROC) curves were generated to identify IR predictors. NAFLD patients had a much higher prevalence of IR than healthy controls (37.8 vs. 2.3 %, P < 0.001). The rates of elevated alanine transferase (ALT) and aspartate transferase (AST) levels were much higher in NAFLD patients with IR than those without (53.7 vs. 41.6 % and 28.6 vs. 18.2 %, respectively, P < 0.001). Uni- and multivariate analyses revealed that female sex, general obesity, abdominal obesity, and hypertension were independent predictors for IR. The area under the ROC curve for fasting plasma insulin (FPI) detecting IR was 0.93 (P < 0.001), and the optimal cutoff was 11.3 mu U/ml (sensitivity = 0.86, specificity = 0.92). Chinese NAFLD patients are susceptible to IR. Female sex, general and abdominal obesity, and hypertension were independent predictors for IR in NAFLD patients. FPI is an optimal predictor for IR.