Gamma-glutamyl transferase as an indicator of obesity: A cross-sectional study

Abstract

Objective: Obesity, characterized by an increase in excessive fat accumulation, represents a social problem worldwide and has been recognized as a major underlying factor in the pathogenesis of several diseases. Gamma-glutamyl transferase (GGT) is a cell-surface protein contributing to the extracellular catabolism of glutathione. Elevated GGT is strongly associated with obesity and excess deposition of fat in the liver, termed non-alcoholic fatty liver disease, which is thought to cause hepatic insulin resistance and contribute to the development of systemic insulin resistance and hyperinsulinemia. Therefore, we have investigated the serum GGT levels in obese individuals and the correlation of serum GGT with body mass index (BMI) and waist circumference. Methods: The study was carried out in 100 obese patients and 100 non-obese individuals. Results: Patients with obesity showed a significant increase in GGT levels when compared to the control group. The mean levels of BMI, WC, total cholesterol, triglycerides, low-density lipoprotein-cholesterol (LDL-c), very LDL-cholesterol, total protein, and aspartate aminotransferase were found to be significantly elevated in the obese individuals compared to controls. The mean levels of high-density lipoprotein-cholesterol showed a significant decrease in the obese participants. Conclusion: Elevated liver enzymes, although in normal ranges, especially at upper quartiles as observed in our study, may play a central role in early diagnosis of fat overflow to the liver. The findings of our study suggest that serum GGT levels may be a simple and reliable marker of visceral fat accumulation.