# Association between lipoprotein combine index and all-cause and cardiovascular mortality in patients undergoing peritoneal dialysis: a multicenter retrospective cohort study

## TL;DR

This study finds that a new cholesterol-related measure called LCI is linked to higher death risks in dialysis patients, especially from heart disease.

## Contribution

The lipoprotein combine index (LCI) is shown to predict mortality better than traditional lipid measures in peritoneal dialysis patients.

## Key findings

- Higher LCI quartiles correlated with increased all-cause and cardiovascular mortality in PD patients.
- Non-linear risk patterns emerged, with mortality rising sharply when LCI exceeded ~20.
- The LCI-CVD mortality link was stronger in patients under 60 years old.

## Abstract

Cardiovascular disease (CVD) is the leading cause of death in patients undergoing peritoneal dialysis (PD). The lipoprotein combine index (LCI), integrating total cholesterol, triglycerides, LDL-C and HDL-C, may better reflect atherogenic burden than traditional single-lipid measures. We hypothesized that higher baseline LCI would be independently associated with increased risks of all-cause and cardiovascular mortality in incident PD patients.

In this multicenter retrospective cohort, 1,986 incident PD patients from six centers (2005–2021) were analyzed. LCI was divided into quartiles (Q1-Q4). Outcomes were all-cause and CVD mortality. Missing covariates were imputed. Centre-stratified Cox models estimated hazard ratios (HRs), and restricted cubic splines assessed non-linear trends.

Over a median 35-month follow-up, 662 deaths occurred, including 328 CVD deaths. Higher LCI quartiles showed progressively higher mortality. For all-cause death, adjusted HRs (95% CI) were 1.41 (1.10–1.80), 1.59 (1.25–2.02) and 1.70 (1.34–2.15) for Q2-Q4 vs. Q1. For CVD death, HRs were 1.45 (1.03–2.02), 1.29 (0.92–1.82) and 1.68 (1.22–2.33). A non-linear pattern was observed for all-cause mortality, with risk increasing when LCI exceeded ~20. The association with CVD mortality was stronger in younger patients (<60 years) (P interaction = 0.048).

Higher baseline LCI independently predicted all-cause and CVD mortality in PD patients, supporting its usefulness for risk stratification and age-specific lipid management.