Low Density Lipoprotein Cholesterol Is Associated With Increased Risk of Cardiovascular Disease in Participants Over 70 Years Old: A Prospective Cohort Study

Abstract Background and Aims Previous studies have indicated that the association of elevated low-density lipoprotein cholesterol (LDL-C) with cardiovascular disease (CVD) varies greatly with age, with the association being much stronger in younger than older individuals. To estimate the relationship between LDL-C and CVD risk in a contemporary population aged over 70 years in China. Methods and Results In this analysis, participants of China Health and Retirement Longitudinal Study (CHARLS) who did not take statins and did not have heart disease and stroke in 2011 were include and were followed up to 2018. The outcome of this analysis was the occurrence of CVD. Cox regression was used to assess the effect of LDL-C on CVD. We calculated E-values to quantify the effect of unmeasured confounding. In the 9,631 participants, 15.2% (N=1,463) were aged over 70 years. During follow-up of 7 years, 1,437 participants had a first CVD attack. The Risk of CVD increased with each 10 mg/mL elevation in LDL-C in whole participants and all age groups. We noted a U-shaped relationship between LDL-C and risk of CVD in group over 70 years old, however, we further found that in the left side of U-shape curve, LDL-C was not associated with CVD, which indicated that a lower level of LDL-C could not increase the risk of CVD. E-value analysis suggested robustness to unmeasured confounding. Conclusions In a contemporary society of China, elevated the level of LDL-C also increased the risk of CVD in participants over 70 years old. These results should strengthen guideline recommendations for the use of lipid-lowering therapies in those elderly.