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 disease (CVD) has not been clarified. This study was to explore their associations in a large PD cohort. Methods This retrospective cohort study included incident patients received PD catheter insertion in our center. The primary outcome was the first CV event (non-fatal myocardial infarction, CV death, non-haemorrhagic stroke, or any arterial revascularisation procedure). Secondary outcomes were 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. Multivariate competing risk model showed no significant association between baseline LDL-C and 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 [SHR]: 1.21, 95% confidence interval [CI]: 1.06–1.39) increased risk of first CV event among peritonitis-free patients, and with an 20% (SHR: 0.80, 95% CI: 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.