Abstract P198: Diabetes Alters the Association Between High-density Lipoprotein Subfractions and Carotid Intima-media Thickness: The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Background: Although HDL-C is inversely associated with cardiovascular risk, no causal relationship has been demonstrated. Since HDL comprises a group of heterogeneous subfractions, they might have different effects on atherosclerosis, and its effects may be modified by the presence of diabetes mellitus. Hypothesis: HDL-C subfractions exert different effects on subclinical carotid atherosclerosis, and diabetes modifies these effects. Methods: We evaluated 3,930 individuals between 35 and 74 years (45.6% men) without previous cardiovascular disease not using lipid-lowering drugs. HDL 2 -C and HDL 3 -C were obtained by zonal ultracentrifugation. The relationships between each HDL-C subfraction and cIMT were analyzed by multiple linear regression models. Results: The mean cIMT was 0.796±0.195 mm, the mean total HDL-C was 55.1±14.4 mg/dl, HDL 2 -C was 14.9±6.7, and HDL 3 was 40.1±8.4 mg/dl. Total HDL-C and subfractions, as well as HDL 2 -C/HDL 3 -C ratio were negatively associated with cIMT after adjustment for race/ethnicity, age, and sex (all p 2 -C: p = 0.01; HDL 3 -C: p = 0.003; HDL 2 -C/HDL 3 -C ratio: p = 0.02). When stratified by diabetes status, both HDL 2 -C (p=0.03) and HDL 2 -C/HDL 3 -C ratio (p= 0.01) showed a negative association with cIMT in people with diabetes (n=531) after adjusting for confounding variables. These associations were not observed in individuals without diabetes (p = 0.11 and p = 0.30, respectively). Conclusion: HDL 2 -C and HDL 3 -C subfractions, as well as the HDL 2 /HDL 3 -C ratio, are inversely associated with cIMT after adjustment for traditional risk factors. This association of HDL 2 -C/HDL 3 -C ratio and HDL 2 -C is modified by the presence of diabetes, where it is more pronounced.