Associations of low-density lipoprotein cholesterol with all-cause and cause-specific mortality in older adults in China

Limited information was available on detailed associations of low-density lipoprotein cholesterol (LDL-C) with all-cause and cause-specific mortality in older adults.This prospective cohort study included a representative sample of 211,290 adults aged 65 or older, who participated in Shenzhen Healthy Aging Research 2018-2019. The vital status of the participants by 31 December, 2021 was determined. We estimated the hazard ratios (HR) with 95% confidence intervals for all-cause or cause-specific mortality using multivariable Cox proportional hazards models and Cox models with restricted cubic spline(RCS) .The median follow-up time was 3.08 years. A total of 5,333 participants were confirmed to have died. Among them, 2,303 cardiovascular disease (CVD) deaths and 1,881 cancer deaths occurred. Compared to those with LDL-C of 100-129 mg/dL, the all-cause mortality risk was significantly higher for individuals with LDL-C level that was very low (< 70 mg/dL) or low (70-99 mg/dL). Compared with individuals with the reference LDL-C level, the multivariable-adjusted HR for CVD-specific mortality was 1.327 for those with very low LDL-C level (< 70 mg/dL), 1.437 for those with high LDL-C level (160 mg/dL ≦ LDL-C < 190mg/dL), 1.528 for those with very high LDL-C level (≥ 190 mg/dL). Low LDL-C level (70-99 mg/dL) and very low LDL-C level (< 70 mg/dL) were also associated with increased cancer mortality and other-cause mortality, respectively. The results from RCS curve showed similar results.Considering the risk of all-causes mortality and cause-specific mortality, we recommended 100-159 mg/dL as the optimal range of LDL-C among older adults in China.