The predictive study of the relation between elevated low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and mortality in peritoneal dialysis

BACKGROUND: The low-density lipoprotein cholesterol to high-density lipoprotein cholesterol (LDL-C/HDL-C) ratio constitutes a strong risk predictor of cardiovascular events. However, the association between this ratio and cardiovascular death in peritoneal dialysis (PD) patients is uncertain. The study aimed to investigate whether a high LDL-C/HDL-C ratio could predict both cardiovascular and all-cause mortalities in patients on PD. METHODS: A total of 1616 incident patients on PD included from January 1, 2006 to December 31, 2013 were followed up with until 31 December 2018 in this single-center prospective cohort study. Participants were divided into three categories according to LDL-C/HDL-C ratio tertile. The primary endpoint was cardiovascular mortality; the secondary endpoint was all-cause mortality. RESULTS: The mean age of the study cohort was 47.5 years and the mean body mass index (BMI) was 21.6 kg/m(2). During a median follow-up period of 47.6 months, 492 patients died, including 246 (50.0%) due to cardiovascular disease (CVD). A multivariate analysis revealed that the highest LDL-C/HDL-C ratio tertile was significantly associated with increased CVD mortality [hazard ratio (HR): 1.69, 95% CI: 1.24–2.29; P = 0.001] and all-cause mortality (HR: 1.46, 95% CI: 1.18–1.81; P = 0.001) relative to the lowest tertile. After adjusting for covariates, the HRs of cardiovascular and all-cause mortalities were 1.84 (95% CI: 1.25–2.71; P = 0.002) and 1.35 (95% CI: 1.03–1.77; P = 0.032). Subgroup analysis showed that the risk of CVD death rose with a higher LDL-C/HDL-C ratio among PD patients who were female, younger than 65 years old, without being malnourished (BMI ≥ 18.5 kg/m(2) or albumin ≥35 g/L), and with a history of diabetes or CVD, respectively. CONCLUSIONS: A high LDL-C/HDL-C ratio is an independent risk factor for both cardiovascular and all-cause mortalities among PD patients.