Associations of Low-density Lipoprotein Cholesterol With All-cause and Cause-specific Mortality in Older Adults in China

Context: Limited information was available on detailed associations of low-density lipoprotein cholesterol (LDL-C) with all-cause and cause-specific mortality in older adults. Methods: 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 December 31, 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). Results: The median follow-up time was 3.08 years. A total of 5333 participants were confirmed to have died. Among them, 2037 cardiovascular disease (CVD) deaths and 1881 cancer deaths occurred. Compared to those with LDL-C of 100 to 129 mg/dL, the all-cause mortality risk was significantly higher for individuals with LDL-C levels that were 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 1.338 for those with very low LDL-C levels (< 70 mg/dL), 1.437 for those with high LDL-C levels (160 mg/dL <= LDL-C < 190 mg/dL), and 1.489 for those with very high LDL-C levels (>= 190 mg/dL). Low LDL-C levels (70-99 mg/dL) and very low LDL-C levels (<70 mg/dL) were also associated with increased cancer mortality and other-cause mortality, respectively. The results from an RCS curve showed similar results. Conclusion: Considering the risk of all-cause mortality and cause-specific mortality, we recommended 100 to 159 mg/dL as the optimal range of LDL-C among older adults in China.