The Effect of Blood Lipid Profiles on Chronic Kidney Disease in a Prospective Cohort: Based on a Regression Discontinuity Design*

Objective Previous studies on the association between lipid profiles and chronic kidney disease (CKD) have yielded inconsistent results and no defined thresholds for blood lipids. Methods A prospective cohort study including 32,351 subjects who completed baseline and follow-up surveys over 5 years was conducted. Restricted cubic splines and Cox models were used to examine the association between the lipid profiles and CKD. A regression discontinuity design was used to determine the cutoff value of lipid profiles that was significantly associated with increased the risk of CKD. Results Over a median follow-up time of 2.2 (0.5, 4.2) years, 648 (2.00%) subjects developed CKD. The lipid profiles that were significantly and linearly related to CKD included total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), TC/HDL-C, and TG/HDL-C, whereas low- density lipoprotein cholesterol (LDL-C) and LDL-C/HDL-C were nonlinearly correlated with CKD. TC, TG, TC/HDL-C, and TG/HDL-C showed an upward jump at the cutoff value, increasing the risk of CKD by 0.90%, 1.50%, 2.30%, and 1.60%, respectively, whereas HDL-C showed a downward jump at the cutoff value, reducing this risk by 1.0%. Female and participants with dyslipidemia had a higher risk of CKD, while the cutoff values for the different characteristics of the population were different. Conclusion There was a significant association between lipid profiles and CKD in a prospective cohort from Northwest China, while TG, TC/HDL-C, and TG/HDL-C showed a stronger risk association. The specific cutoff values of lipid profiles may provide a clinical reference for screening or diagnosing CKD risk.