Influence of insulin resistance in obese patients on elevated serum alanine aminotransferase

D.A. de Luis, R. Aller*, O. Izaola, M. Gonzalez Sagrado, R. Conde, J.M. Gonzalez Hernandez*

Institute of Endocrinology and Nutrition, Medicine School and Unit of Investigation, Hospital Rio Hortega, University of Valladolid; *Digestive Dept. Hospital Clinico Universitario – Valladolid (Spain)

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• Internal Medicine

Background and Objective: Insulin resistance has been associated with fat liver and non-alcoholic fatty liver disease. The aim of our study was to study the influence of insulin resistance in obese patients on elevated serum alanine aminotransferase.

Research Methods: A population of 91 obesity non diabetic outpatients was analyzed in a cross sectional study. HOMA-IR was calculated as indicator of insulin resistance.

Results: The mean age was 39.2 ± 16.7 years and the mean BMI 34.4 ± 5.2. Patients were classified as group I (control, n = 74) when serum (Alanine Aminotransferase) ALT activity was normal or group II (NAFLD, n = 17) when serum ALT activity was greater than the upper limit of normal reference laboratory (>= 43 UI/L). Waist circumference, fat mass and hip to waist ratio were higher in group II. Insulin (13.5 ± 7.8 mUI/L vs 24.9 ± 16.7 mUI/L; p < 0.05), HOMA-IR (1.9 ± 1.1 vs 3.9 ± 2.8), and triglycerides levels (115.1 ± 66.8 mg/dl vs 153.2 ± 71.2 mg/dl; p < 0.05) were higher in group II than group I. In the logistic regresion analysis with a dependent dicotomic variable (ALT; group I and group II), the HOMA-IR remained in the model, with an Odd’s Ratio to develop ALT > 43 U/L of 2.18 (CI:95%: 1.12-4.2) with each 1 unit of HOMA-IR adjusted by age, sex, weight, and dietary intake.

Conclusion: Insulin resistance in obese patients is associated with ALT activity. Further study is needed to evaluate histological changes and new treatments in these patients.

Corresponding Author: Daniel A de Luis, MD; e-mail: dadluis@yahoo.es