Association between bilirubin and chronic kidney disease in hypertensive patients: The China hypertension registry study

Limited data exists on the association between Direct bilirubin (DBIL) and Indirect bilirubin (IBIL) with the risk of chronic kidney disease (CKD) among patients with hypertension. This study aimed to assess the relationship between DBIL and IBIL with the risk of CKD in a cohort of Chinese adults diagnosed with hypertension. This study included 14 182 Chinese patients with hypertension between the ages of 27 and 96. CKD, the outcome variable, was defined by an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. The study employed multivariate linear and multivariate logistic regression analysis to evaluate the correlation between DBIL and IBIL with the risk of CKD. The prevalence of CKD in the study population was 9.77%. Multivariate logistic regression analysis showed that the increase in DBIL (OR: 0.66; 95% CI: 0.61, 0.71) and IBIL (OR: 0.75; 95% CI: 0.71, 0.81) were independently and negatively correlated with CKD. Further analyses using a restricted cubic spline (smooth-fitting curve) confirmed the linearly negative association between DBIL and IBIL with the risk of CKD. The subgroup analysis showed that the correlation between IBIL and CKD was stronger among men and populations <65 years of age (p for interaction <.05). DBIL and IBIL were independently and negatively associated with CKD. Furthermore, the correlation between DBIL and IBIL with CKD in the hypertensive population is more significant in those under 65 years of age. These findings may inform future strategies for the management of CKD.