Abstract 36: Changes in HDL Particle Traits in Response to Regular Exercise: Results from the HERITAGE Family Study

Given the controversy around HDL-C as a therapeutic target, there is a need to investigate other features of HDL and how they respond to various preventive interventions. We tested the hypothesis that regular exercise would have beneficial effects on HDL particle (HDL-P) traits in sedentary adults. Methods: The following HDL-P traits were measured via NMR (Liposcience Inc.) before and after completion of a 20-week exercise program in the HERITAGE Family Study (N=715): concentration of total, large, medium, and small HDL-P and mean HDL-P size. ANCOVA was used to test for aggregation of HDL-P trait responses in families controlling for age, sex, and baseline BMI and trait value. Results: The concentration of large HDL-P significantly increased in response to regular exercise in both Black and White participants, while the increase was significantly larger in females compared to males (Table 1). In general, regular exercise decreased the concentration of medium and small HDL-P. Together, these responses contributed to a significant increase in the average cholesterol content of HDL particles. Exercise-induced changes in large HDL-P were inversely correlated with changes in fat mass and systolic blood pressure. Moreover, changes in BMI were significantly associated with changes in all of the HDL-P traits, but not with HDL-C. We found significant evidence of familial aggregation for the exercise-induced changes in HDL-P traits in both races, as there was 1.4 to 1.6 times more variance between than within families for the changes in total (p=0.02 in Whites) and large HDL-P (p=0.004 in Whites, p=0.02 in Blacks) and HDL-P size (p=0.0009 in Whites, p=0.009 in Blacks). Conclusion: The HDL-P subclass profile favorably responded to regular exercise in sedentary Black and White adults, highlighted by increases in the concentration of large HDL-P, and may be influenced by a significant genetic component. We provide evidence that regular exercise could potentially be used as an HDL-based therapy designed to target beneficial subfractions.