Association of serum gamma-glutamyltransferase with chronic kidney disease risk: a meta-analysis

Studies on the association between gamma-glutamyltransferase (GGT) and chronic kidney disease (CKD) have produced conflicting results. This study aimed to investigate the association of elevated GGT with the risk of CKD in the adult general population by performing a meta-analysis of relevant articles. We searched PubMed, Web of Science, and Embase databases from their inception to October 2017 to identify observational studies regarding the association between serum GGT level and CKD. Pooled risk ratio (RR) and 95% confidence intervals (CI) was calculated as the effective measures. Eight studies with 116 011 individuals were included in this meta-analysis. Overall, individuals with the highest versus the lowest GGT level were not associated with an increased risk of CKD (RR 1.14; 95% CI 0.99-1.31). Subgroup analysis showed that the pooled RR for the highest versus the lowest GGT category was 1.31 (95% CI 1.06-1.60) for the Asian countries and 1.04 (95% CI 0.88-1.23) for the Western countries. In the sex-stratified analysis, no significant associations of elevated GGT with risk of CKD were found for both women (RR 0.95; 95% CI 0.84-1.07) and men (RR 1.08; 95% CI 0.86-1.36). This meta-analysis demonstrates no significant association between elevated serum GGT and risk of CKD in the adult general population. However, future well-designed studies are needed to evaluate the impact of geographical region on the association.