Relationship between Serum gamma-glutamyltransferase Level and Serum Ferritin Level in Healthy Adults

ABSTRACT

BACKGROUND: Serum gamma-GT is one of the biliary enzymes with the only enzymatic activity capable of cleaving extracellular glutathione, thus originating precursor amino acids for the intracellular resynthesis of glutathione. Several population-based studies have shown a strong cross-sectional association between serum gamma-GT concentration and cardiovascular risk factors. And prospective studies showed that serum gamma-GT concentration had a prognostic impact on cardiovascular mortality. But, the mechanism by which gamma-GT is associated with cardiovascular disease is not elucidated. We hypothesized that there was an association between serum gamma-GT and ferritin, a marker of oxidative stress. In this study, we investigated the relationship between serum gamma-GT and serum ferritin. METHODS: By reviewing the medical records of 288 healthy adults, we determined the serum levels of gamma-GT and ferritin according to age, body mass index, systolic blood pressure, diastolic blood pressure, triglycerides, total cholesterol, LDL-cholesterol, fasting blood sugar, hs-CRP, serum ferritin, AST, ALT, uric acid and smoking history. We studied the relationship between the variables by Pearson correlation coefficients and multiple stepwise regression analysis. Mean values of serum gamma-GT according to the smoking history were compared using t-test. RESULTS: Serum gamma-GT correlated positively with serum ferritin (r=0.42; P<0.001). BMI, triglycerides, total cholesterol, fasting blood sugar, AST and ALT also showed statistically significant correlation. Smokers showed significantly higher serum gamma-GT. Serum gamma-GT correlated with serum ferritin, ALT, current smoking and triglycerides by multiple stepwise regression analysis. CONCLUSION: Serum gamma-GT correlated positively with serum ferritin.