Low-density lipoprotein cholesterol was inversely associated with 3-year all-cause mortality among Chinese oldest old: data from the Chinese Longitudinal Healthy Longevity Survey

Abstract

Objective: Low-density lipoprotein cholesterol (LDL-C) is a risk factor for survival in middle-aged individuals, but conflicting evidence exists on the relationship between LDL-C and all-cause mortality among the elderly. The goal of this study was to assess the relationship between LDL-C and all-cause mortality among Chinese oldest old (aged 80 and older) in a prospective cohort study.

Methods: LDL-C concentration was measured at baseline and all-cause mortality was calculated over a 3-year period. Multiple statistical models were used to adjust for demographic and biological covariates.

Results: During three years of follow-up, 447 of 935 participants died, and the overall all-cause mortality was 49.8%. Each 1 mmol/L increase of LDL-C concentration corresponded to a 19% decrease in 3-year all-cause mortality (hazard ratio [HR] 0.81, 95% confidence interval [CI] 0.71-0.92). The crude HR for abnormally higher LDL-C concentration (≥3.37 mmol/L) was 0.65 (0.41-1.03); and the adjusted HR was statistically significant around 0.60 (0.37-0.95) when adjusted for different sets of confounding factors. Results of sensitivity analysis also showed a significant association between higher LDL-C and lower mortality risk.

Conclusions: Among the Chinese oldest old, higher LDL-C level was associated with lower risk of all-cause mortality. Our findings suggested the necessity of re-evaluating the optimal level of LDL-C among the oldest old.

Keywords: China; Epidemiology; LDL-C; Mortality; Oldest old.