Peritonitis Affects the Relationship Between Low-Density Lipoprotein Cholesterol and Cardiovascular Events in Peritoneal Dialysis Patients

Abstract Background In peritoneal dialysis (PD), the relationship among low-density lipoprotein cholesterol (LDL-C), peritonitis, and cardiovascular (CV) disease has not been clarified. This study was performed to explore their associations in a large PD cohort. Methods This retrospective cohort study included incident patients who received PD catheter insertion in our centre. The primary outcome was the first CV event (nonfatal myocardial infarction, CV death, non-haemorrhagic stroke, or any arterial revascularization procedure). Secondary outcomes were the occurrence of peritonitis, CV mortality, and all-cause mortality. Results This study included 1294 patients, whose mean age was 48.1 years. After adjustment for confounders in negative binomial regression models, lower LDL-C quartiles were independently associated with a higher risk of peritonitis, compared with the highest quartile. The multivariate competing risk model showed no significant association between baseline LDL-C and the first CV event in the overall population. However, stratified analysis showed that each 1 mmol/L increase in LDL-C was independently associated with a 21% (subdistribution hazard ratio: 1.21, 95% confidence interval: 1.06-1.39) increased risk of the first CV event among peritonitis-free patients, and with a 20% (subdistribution hazard ratio: 0.80, 95% confidence interval: 0.65-0.99) decreased risk among patients with peritonitis. Moderating-effect analysis showed that the presence of peritonitis significantly influenced the relationships between LDL-C and CV events (P Conclusions PD patients with lower baseline LDL-C had a higher risk of peritonitis. The effect of LDL-C on CV events and mortality was different by the presence of peritonitis events.