Role of γ-glutamyl transferase levels in prediction of high cardiovascular risk among patients with non-alcoholic fatty liver disease

BACKGROUND & OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is an important cause of elevated liver functions. There is evidence showing an association between NAFLD and subclinical atherosclerosis independent of traditional risk factors. We undertook this retrospective study to determine the association of Framingham cardiovascular risk scoring system with liver function tests and inflammatory markers and to find the role of liver function tests in determination of CVD risk among non-obese and non-diabetic subjects with non-alcoholic fatty liver disease. METHODS: A total of 2058 patients were included in the study. Framingham cardiovascular risk scoring was done of all patients according to the age, gender, systolic blood pressure, serum total cholesterol and HDL cholesterol levels, smoking and antihypertensive medication history. Liver function test, lipid profile, insulin, uric acid, ferritin levels, etc. were determined. RESULTS: According to the ultrasonography findings, patients were grouped as without any fatty infiltration of the liver (control group) (n=982), mild (n=473), moderate (n=363) and severe fatty liver disease (n=240) groups. In severe fatty liver disease group, the mean Framingham cardiovascular risk score was significantly higher than that of other groups. There was a positive correlation between GGT, uric acid and ferritin levels with Framingham cardiovascular score. In multivariate analysis, high GGT levels were positively associated with high-risk disease presence (OR: 3.02, 95% CI: 2.62-3.42) compared to low GGT levels independent of the age and sex. INTERPRETATION & CONCLUSIONS: Cardiovascular disease risk increases with the presence and stage of fatty liver disease. Our findings showed a positive correlation between elevated GGT levels and Framingham cardiovascular risk scoring system among non-diabetic, non-obese adults which could be important in clinical practice. Though in normal limits, elevated GGT levels among patients with fatty liver disease should be regarded as a sign of increased cardiovascular disease risk. Larger studies are warranted to elucidate the role of GGT in prediction of cardiovascular risk.