The Relationship Between Low-Density Lipoprotein Cholesterol Levels and Cardiovascular Risk in Koreans With and Without Diabetes

Objective: The association between low-density lipoprotein cholesterol (LDL-C) levels and cardiovascular disease (CVD) is well-established. However, data on LDL-C thresholds specific to certain populations for assessing CVD risk, particularly among individuals without diabetes, remain limited. This study investigated the association between LDL-C levels and CVD risk in Koreans, comparing individuals with and without diabetes, and evaluated the differential impact of statin therapy. Methods: A nationwide cohort study was conducted using data from 4,668,406 individuals without prior CVD. Participants were categorized into 6 LDL-C groups: <70, 70-99, 100-129, 130-159, 160-189, and ≥190 mg/dL. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) for CVD outcomes, adjusting for demographic, clinical, and lifestyle factors. Results: During a median follow-up period of 6 years, 67,935 CVD events occurred. LDL-C levels ≥100 mg/dL were significantly associated with increased CVD risk regardless of diabetes status, with progressively higher HRs in elevated LDL-C categories. Among statin users, CVD risk increased significantly from LDL-C levels ≥130 mg/dL in individuals without diabetes, whereas risk rose starting from LDL-C ≥100 mg/dL in individuals with diabetes. Conclusion: Our study demonstrates that individuals without diabetes require strict LDL-C control to levels below 100 mg/dL, similar to the control recommended for those with diabetes. Moreover, the cardiovascular risk associated with LDL-C in statin-treated individuals differs based on diabetes status. These findings highlight the importance of individualized LDL-C management strategies that account for glycemic status.