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.

BACKGROUND: Metabolic syndrome (MetS) is a known predictor of diabetes mellitus (DM), but whether longitudinal changes in MetS status modify the risk for DM remains unclear. We investigated whether changes in MetS status over 2 years modify the 10-year risk of incident DM. METHODS: We analyzed data from 7,317 participants aged 40 to 70 years without DM at baseline, who took part in 2001 to 2011 Korean Genome Epidemiology Study. Subjects were categorized into four groups based on repeated longitudinal assessment of MetS status over 2 years: non-MetS, resolved MetS, incident MetS, and persistent MetS. The hazard ratio (HR) of new-onset DM during 10 years was calculated in each group using Cox models. RESULTS: During the 10-year follow-up, 1,099 participants (15.0%) developed DM. Compared to the non-MetS group, the fully adjusted HRs for new-onset DM were 1.28 (95% confidence interval [CI], 0.92 to 1.79) in the resolved MetS group, 1.75 (95% CI, 1.30 to 2.37) in the incident MetS group, and 1.98 (95% CI, 1.50 to 2.61) in the persistent MetS group (P for trend <0.001). The risk of DM in subjects with resolved MetS was significantly attenuated compared to those with persistent MetS over 2 years. In addition, the adjusted HR for 10-year developing DM gradually increased as the number of MetS components increased 2 years later. CONCLUSION: We found that discrete longitudinal changes pattern in MetS status over 2 years associated with 10-year risk of DM. These findings suggest that monitoring change of MetS status and controlling it in individuals may be important for risk prediction of DM.
Diabetes Mellitus ; Epidemiology ; Follow-Up Studies ; Genome ; Life Style ; Proportional Hazards Models