Aims: Previous studies have indicated the link of bilirubin levels and risk of developing chronic kidney disease (CKD); however, the findings were inconsistent.
Methods: We searched for cohort studies examining bilirubin as an exposure and CKD as an outcome in the Medline, EMBASE, and Web of Science databases from inception through November 31, 2016. A generalized least-squares approach was applied to assess the dose-response relationship between them by pooling rate ratios with 95% confidence intervals. Subgroup analyses, sensitivity analysis, meta-regression, and publication bias were also conducted.
Results: Seven cohort studies with 1316 cases and 21,076 participants were identified for inclusion in the meta-analysis. The combined RR for the highest versus lowest bilirubin level was 0.36 (95% CI 0.19-0.68; P heterogeneity = 0.001; Power = 0.72; n = 6). In the linear dose-response analysis, each 1-μmol/L increase in bilirubin was associated with a 5% reduced risk of CKD (RR = 0.95; 95% CI 0.92-0.97; P for trend test = 0.113; P heterogeneity = 0.001; Power = 0.99; n = 7). The subgroup analyses and sensitivity analyses showed consistent results, and publication bias may exist.
Conclusion: This meta-analysis suggests that elevated bilirubin level may be associated with decreased risk of developing CKD.
Keywords: Bilirubin; Chronic kidney disease; Cohort studies; Dose–response meta-analysis.