Remnant Cholesterol and Atherosclerotic Cardiovascular Disease Risk in Populations With Different Low‐Density Lipoprotein Cholesterol Elevations: A Prospective Cohort Study

Background Low‐density lipoprotein cholesterol (LDL‐C) and remnant cholesterol (RC) are risk factors for atherosclerotic cardiovascular disease (ASCVD). However, the extent to which differences in RC levels affect ASCVD risk in populations with varying degrees of LDL‐C elevation remains unclear. This study aimed to investigate whether RC can provide additional risk stratification value across different sexes, ages, and elevated LDL‐C statuses. Methods This study included 12 743 elevated LDL‐C participants (LDL‐C ≥3.4 mmol/L) and 50 073 age‐ and sex‐matched non‐elevated LDL‐C controls from the Kailuan Study. Elevated LDL‐C participants were categorized by RC levels into <0.5, 0.5 to <1.0, and ≥1.0 mmol/L subgroups. Kaplan‐Meier curves and Cox proportional hazards models were used to assess the relationship between RC levels and ASCVD risk across different sexes, ages, and high LDL‐C statuses. Results During a median follow‐up of 12.8 years, 1686 elevated LDL‐C participants (13.2%) and 5252 non‐elevated LDL‐C participants (10.5%) developed ASCVD. In the borderline‐high LDL‐C group (3.4 ≤ LDL‐C < 4.1 mmol/L), those with the lowest RC levels showed no significant risk difference compared with controls (hazard ratio [HR], 1.03 [95% CI, 0.93–1.13]), and this pattern remained consistent across different sexes and ages. In contrast, in the high LDL‐C group (LDL‐C ≥4.1 mmol/L), even when RC was at the lowest level, ASCVD risk remained significantly higher than that of controls (HR, 1.20 [95% CI, 1.02–1.41]). Conclusions In the borderline‐high LDL‐C population, those with the lowest RC levels showed no significant risk difference compared with controls, and this pattern remained consistent across different sexes and age subgroups. In the high LDL‐C population, even when RC was at the lowest level, ASCVD risk remained significantly higher than that of controls.