Association between serum γ-glutamyltransferase and chronic kidney disease in urban Han Chinese: a prospective cohort study

Limited numbers of literatures have focused on the association between gamma-glutamyltransferase (GGT) and chronic kidney disease (CKD), and their results were controversial. Therefore, in this study, we set up a large-scale cohort of Chinese population to discover and verify the association between serum GGT and CKD. Our cohort study was based on 21,818 patients who visited Health Management Center of Shandong Provincial Hospital, China, to receive routine health check-up during the period of 2005-2010, and we used multivariate Cox regression model to clarify whether elevated serum GGT increased the risk of CKD or not. During the follow-up of 57,891 person-years, 1456 patients developed CKD, giving rise to an incidence density of 25.15 per 1000 person-years (1456/57,891 person-years). After adjusting gender, age, baseline serum creatinine (SCr), body mass index (BMI), serum albumin (ALB), alanine aminotransferase (ALT), hemoglobin, white blood cell count (WBC), triglyceride (TG), total cholesterol (TC), hypertension, cardiovascular disease (CVD), diabetes, smoking and drinking status, the risk for CKD increased with the elevated serum GGT quartiles. The hazard ratio (HR) for CKD was 1.326 (95 % confidence interval (CI), 1.073-1.639) when the top quartile of serum GGT was compared with the bottom one, and the HR of log-transformed serum GGT for CKD was 1.658 (95 % CI, 1.294-2.125). The results were consistent in males but different in females when gender was stratified. The result reveals that there is a positive relationship between increasing serum GGT levels and the incidence of CKD which suggests that elevated GGT level could be a potential indicator for risk of CKD.