The association between time-weighted remnant cholesterol and respiratory-related mortality: A population-based cohort study

<bold>Background:</bold> Remnant cholesterol (RC) have been suggested as an important mediator of atherosclerotic cardiovascular disease. However, its relationship with cause-specific long-term mortality remains uncertain. This study investigated the associations between time-weighted RC and mortality outcomes. <bold>Methods:</bold> This retrospective population-based study enrolled patients between 1st January 2000 and 31st December 2003 with at least three RC testing results. The time-weighted RC was calculated by the products of the sums of two consecutive measurements and the time interval divided by the total time. The primary outcomes were all-cause mortality and cause-specific mortality. Cox regression and marginal effective plots were applied to identify associations between time-weighted RC and respiratory-related and all-cause mortality. <bold>Results:</bold> A cohort of 75,342 patients (39.69% males, mean age: 61.3 years old) were included. Over follow-up of 19 years, multivariable Cox regression adjusting for demographics, comorbidities, medications, and time-weighted laboratory results found that time-weighted RC was associated with all-cause mortality (Hazard ratio [HR]: 1.41; 95% Confidence Interval [CI]: 1.35-1.48) but a ‘one off’ single RC measurement was not (HR: 0.99; 95% CI: 0.89-1.10). Time-weighted RC was also associated with increased risks of respiratory-related mortality (HR: 1.33; 95% CI: 1.20-1.47). Time-weighted RC was also associated with pneumonia-related mortality (HR: 1.33; 95% CI: 1.20-1.48). <bold>Conclusions:</bold> Time-weighted RC was independently associated with all-cause and respiratory-related mortality.