Endocrine Abstracts

Background: Obesity has become a worldwide epidemic and carries excess cardiovascular morbidity and mortality. HDL efflux capacity (HEC) was shown to be inversely correlated with cardiovascular risk (CVR), both in the acute and the chronic phases. Our aim was to understand if decreased HEC can serve as a surrogate marker for the increased CVR in this population.

Methods: Forty patients: 10 obese diabetic (OD), 10 obese non-diabetic (OND), 10 with stable Coronary Artery Disease (sCAD) and 10 healthy controls were blindly selected from another cohort and their HECs were studied using radioactive cell-based assays.

Results: The mean age of the cohort was 50±12 years, with 72.5% men. Mean BMI for the obese groups was 46.8±7.03 kg/m², for the sCAD group 27.7±3.3 kg/m² and for the controls 24.2±2.26 kg/m². Mean HEC (adjusted to ApoA1 mass) was 14.18±0.95% for the OD group, 14.73±3.18% for the OND group, 19.11±1.6% for the sCAD group and 16.01±1.6% for the controls. A linear regression model adjusted for age, sex, BMI and TG has found that both OD and OND have significantly lower HEC in comparison to controls (P<0.05 for both), whereas the sCAD did not.

Discussion: In the current study, we found that morbidly obese individuals have significantly lower HEC in comparison to controls. Given that HEC has an inverse correlation with CVR, these finding may explain, at least in part, the increased CVR in morbidly obese patients. It is unclear if bariatric surgery improves HEC, but it is reasonable to speculate it does, given the other metabolic effects the surgery exerts.

Conclusion: HDL function is compromised in morbidly obese individuals and contributes to progressive atherosclerosis and increased CVR in this population. If HEC does improve post-metabolic surgery, decreased HEC might serve as another indication for bariatric surgery.