Relationship of insulin resistance and adipocytokines on serum alanine aminotransferase in presurgical morbid obese patients

Abstract

Background and objective: Insulin resistance and adipocytokines have been associated with fat liver and non-alcoholic fat liver disease (NAFLD). The aim of this research was to study the influence of insulin resistance and adipocytokines in presurgical morbid obese patients on elevated serum alanine aminotransferase (ALT) as an indicator of NAFLD.

Subjects and methods: A population of 65 presurgical morbid obese patients was analyzed in a cross sectional study. HOMA-IR was calculated as indicator of insulin resistance. Adipocytokines (leptin, resistin, adiponectin, Interleukin-6 and TNF alpha) blood levels were measured.

Results: Patients were classified as group I (n=33) when serum ALT activity was normal or group II (NAFLD patients; n=32) when serum ALT activity was greater than the median value of the group (> or =24 UI/L). In NAFLD group, BMI, weight, fat mass, waist to hip ratio, waist circumference, HOMA and insulin levels were higher than control group. Adiponectin levels were lower in group II than I. Anthropometric parameters were higher in both groups. In the multivariate analysis with dietary intake-, age- and sex-adjusted ALT concentration as a dependent variable, only HOMA remained as an independent predictor in the model (F=12.1; p<0.05). ALT concentration increased 0.48 UI/L (CI95%: 0.19-0.76) for each unit of HOMA increased.

Conclusion: Anthropometric parameters and insulin resistance are associated with elevated serum alanine aminotransferase in obese morbid patients with lower levels of adiponectin. However, in a multiple regression model only insulin resistance remained in the model.