Nonalcoholic fatty liver disease markers are associated with insulin resistance in type 1 diabetes.

backgroundNonalcoholic fatty liver disease (NAFLD) has been associated with the insulin resistance.

aimsTo explore the relationship between markers of NAFLD, namely concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALK), γ-glutamyltransferase (GGT), ferritin and bilirubin and insulin resistance in type 1 diabetes.

methodsOur study included 353 patients with type 1 diabetes. Insulin sensitivity was measured with estimated glucose disposal rate calculated using the equation: eGDR = 24.31 - (12.22 × WHR) - (3.29 × HT) - (0.57 × HbA1c); WHR = waist to hip ratio, HT = hypertension. Correlations and multiple logistic regressions analysis were performed to identify the relationships between NAFLD associated markers and eGDR, individual components of insulin resistance and risk of insulin resistance.

resultsAST, ALT, AST-to-ALT ratio, ALK and ferritin significantly correlated with insulin resistance measured by eGDR (r = -0.13, -0.14, 0.13, -0.18, and -0.24, respectively; all P < 0.05), and with individual components of insulin resistance, most notably WHR. In a multiple logistic regression model adjusted according to age, sex, duration of diabetes and BMI, increased levels of AST, ALT and ALK resulted in an increased risk for the development of insulin resistance in our subjects (OR = 1.03, 1.02, and 1.01, respectively; all P < 0.05).

conclusionsThese findings indicate that higher levels of ALT, AST and ALK are additional markers of insulin resistance in type 1 diabetes and suggest that those subjects must be considered as potentially affected not only by a hepatic but also by a multisystemic disease through altered insulin sensitivity.