Abstract P038: Association Of Discordance Between Low-density Lipoprotein And High-density Lipoprotein Cholesterol Versus Particle Concentration With Incidence Of Type 2 Diabetes: Coronary Artery Risk Development In Young Adults Study

Abstract

Background: The body of literature on discordance between lipoprotein cholesterol and particle concentrations focuses primarily on the relationship between lipoprotein discordance and clinical and subclinical indices of cardiovascular disease. Data are sparse regarding associations between either high (HDL) or low (LDL) density lipoprotein discordance and incident type 2 diabetes (T2D). Purpose: To test the hypothesis that both HDL and LDL discordance status are associated with incident T2D. Methods: All included phenotypes were measured at the year 7 exam among 3891 participants of the CARDIA study. Diabetes status at each exam was classified as a fasting glucose above 126 mg/dL. Sex-specific median-based lipoprotein discordance groups were created and combined into four exclusive cholesterol/particle groups for both HDL and LDL: 1) low/low (below the median for both cholesterol and particle concentration), 2) low/high (below the median for cholesterol, at or above the median for particle concentration), 3) high/low, and 4) high/high. The association of incident T2D with lipoprotein discordance was assessed via sex-specific multivariable proportional hazards regression. All sex-specific models were adjusted for self-identified race and the time varying covariates of age, smoking, and BMI. In the instance of a significant race by discordance interaction term, race-specific models were utilized. The low cholesterol/low particle groups were used as the reference group for all analyses. Results: Approximately 27% of men and 34% of Women were discordant (either low/high or high/low) for HDL while around 15% of both men and women were discordant for LDL. In women only, both HDL and LDL discordance were associated with incident T2D with higher risk associated with lower HDL-C (Low HDL-C/High HDL-P at highest risk of incident T2D; Hazard Ratio [HR] 1.7, 95% confidence interval [CI] 1.1 to 2.6, p=0.01). Race-specific associations were found for LDL discordance with T2D risk, with the High LDL-C/High LDL-P group at higher risk (Black participants only: HR 1.5, 95%CI 1.03 to 2.4, p<0.01). No significant relationships between lipoprotein discordance and T2D incidence were found for males. Conclusions: Lipoprotein concordance/discordance status is significantly associated with incident T2D in women only, although racial differences may be present. These data suggest that measurement of lipoprotein particle concentrations alongside cholesterol measures may provide novel insight into health risks and prevention needs.