Effects of bariatric surgery on HDL structure and functionality: results from a prospective trial

BACKGROUND: In addition to high-density lipoprotein cholesterol (HDL-C) levels, HDL quality appears also very important for atheroprotection. Obese patients with metabolic syndrome have significantly reduced HDL-C levels and are usually at increased risk for coronary heart disease. Despite that weight loss benefits these patients, its effects on HDL quality and functionality is currently poorly studied. OBJECTIVES: We investigated how rapid weight loss affects HDL structure and its antioxidant potential in patients undergoing a malabsorptive bariatric procedure. METHODS: Fasting plasma samples were collected the day before and 6 months after the bariatric procedure from 20 morbidly obese patients with body mass index >50, then HDL was isolated and analyzed by biochemical techniques. RESULTS: We report a dramatic alteration in the apolipoprotein ratio of HDL that was accompanied by the presence of more mature HDL subspecies and a concomitant increase in the antioxidant potential of HDL Interestingly, our obese cohort could be distinguished into 2 subgroups. In 35% of patients (n = 7), HDL before surgery had barely detectable apolipoprotein (apo) A-I and apoCIII, and the vast majority of their HDL cholesterol was packed in apoE-containing HDL particles. In the remaining 65% of patients (n = 13), HDL before surgery contained high levels of apoA-I and apoCIII, in addition to apoE. In both subgroups, surgical weight loss resulted in a switch from apoE to apoA-I containing HDL. CONCLUSIONS: Rapid weight loss exerts a significant improvement in HDL structure and functionality that may contribute to the documented beneficial effect of malabsorptive bariatric procedures on cardiovascular health. (C) 2014 National Lipid Association. All rights reserved.