The relationship between remnant cholesterol and future renal function decline in middle-aged and elderly Chinese populations: the mediating role of uric acid and white blood cells.

: The relationship between remnant cholesterol (RC) and renal function decline (RFD) remains unclear. This research evaluated the connection between RC and RFD across a substantial Chinese population. : We selected participants from the 2011 China Health and Retirement Longitudinal Study (CHARLS) survey, 4,227 participants were identified as not having RFD and were consequently recruited for the study. These participants were then subject to follow-up in 2015. Logistic regression analyses and Restricted cubic spline (RCS) were conducted to explore the association between RC and RFD. An analysis of mediation was performed to investigate the possible mediating factors in this relationship. : Following a 4-year period of follow-up, 191 cases (4.52%) of renal function decline events were identified. In the longitudinal study, after adjusting for potential confounders, the incidence of renal function decline still increased with increasing RC levels and was indicated by an odds ratio (OR) of 1.41; 95% CI: 1.17 - 1.66;  = 0.0001. Subgroup analyses indicated no significant interactions between all groups and RC (all for interaction > 0.05). The results of the RCS analysis demonstrated a significant linear relationship between RC and RFD in both the cross-sectional study and the longitudinal study. Uric acid and white blood cells each showed partial mediating effects (10.47% and 8.86%, respectively) in longitudinal analyses. Our research indicates that RC is positively and linearly associated with RFD. In addition, uric acid and white blood cells play significant partial mediating roles in this process.