The Association between the Low-density Lipoprotein-Cholesterol to High-density Lipoprotein-Cholesterol Ratio and the Incidence of Type 2 Diabetes Mellitus in Korean Adults: A Secondary Data Analysis Using a Community-based Cohort Study in Korea

Purpose: This study investigated the association between the low-density lipoprotein-cholesterol/high-density lipoprotein-cholesterol (LDL-C/HDL-C) ratio and the incidence of diabetes in a Korean community-based cohort.Methods: The participants were 7,653 adults aged 40-69 years without diabetes at baseline from Korean Genome and Epidemiology Study who were followed up for 16 years biennially. These participants were categorized into four groups (Q1-Q4) according to quartiles of LDL-C/HDL-C ratio at baseline. Significant differences in the probability of diabetes-free survival curve were identified using the log-rank test in Kaplan-Meier analysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression analysis.Results: In total, 1,833 (24.0%) participants newly developed diabetes. The overall incidence of diabetes was 20.37 per 1,000 person-years (14.94, 17.12, 22.0, and 22.08 per 1,000 person-years for Q1, Q2, Q3, and Q4, respectively). The probability of diabetes-free survival was significantly different among the four groups (log-rank, x2=117.88, p<.001). Covariates included age, sex, triglyceride, fasting plasma glucose, homeostatic model assessment for insulin resistance index, hypertension, body mass index, family history of diabetes mellitus, smoking status, and alcohol use. Multivariate Cox proportional hazards regression showed that people with the highest quartile of the LDL-C/HDL-C ratio had a 1.17 times higher (HR=1.17, 95% CI: 1.01~1.35, p=.038) risk of diabetes development than those in the lowest quartile after adjusting for covariates.Conclusion: The LDL-C/HDL-C ratio is an independent risk factor for diabetes development. Measuring and managing the LDL-C/HDL-C ratio is necessary for detecting individuals at high risk for developing diabetes.