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

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.

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 (> or =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 regression 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.

CONCLUSIONS

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