Objective: To investigate the association of diabetes duration with cardiovascular disease (CVD) risk and to examine the relationship between lipid levels and CVD risk over the duration.
Methods: Using the Korean National Health Insurance Service Cohort database, we identified 2,359,243 subjects with type 2 DM aged ≥20 years in 2015-2016. Baseline lipid levels and diabetes duration were evaluated, and followed up until December 2020 (mean follow-up, 3.9 years). Subjects were categorized according to diabetes duration (new-onset, <5 years, 5-9 years, or ≥10 years). We analyzed the new-onset diabetes group with low-density lipoprotein cholesterol (LDL-C), <70 mg/dL, as the reference group. The hazard ratios (HRs) and 95% confidence intervals (CIs) of myocardial infarction (MI), and ischemic stroke (IS) were estimated using a Cox proportional hazards model adjusted for potential confounders.
Results: During follow-up, 45,883 cases of MI and 53,538 cases of IS were identified. The risk of MI or IS began to increase at LDL-C ≥160 mg/dL in the new-onset diabetes group, and at LDL-C ≥130 mg/dL in the diabetes duration <5 years group. Among subjects with a diabetes duration of 5-9 years, LDL-C 100-129 mg/dL, LDL-C 130-159 mg/dL, and ≥160 mg/dL were significantly associated with the risk of MI, with HRs (95% CI) of 1.13 (1.04-1.22), 1.28 (1.17-1.39), and 1.58 (1.42-1.76), respectively. The risk of MI in the diabetes duration ≥10 years group was increased by 16%, even in the LDL-C 70-99 mg/dL population (HR [95% CI] 1.16 [1.08-1.25]).
Conclusions: This population-based longitudinal study revealed that the LDL-C cutoff level for increasing the risk of cardiovascular disease varied with diabetes duration, and that the target LDL-C level should depend on the duration.
Keywords: Korea; cardiovascular disease; cholesterol; diabetes mellitus; duration.
© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.