Effects of Bariatric Surgery on HDL Cholesterol

Background Low levels of high-density lipoprotein cholesterol (HDLc) are independent predictive factors of coronary heart disease. Bariatric surgery increases HDLc concentration, but the chronology and predictors of this improvement in HDLc levels are not well-established. The aim of the present study was to analyse the changes over time in HDLc concentrations after bariatric surgery and to determine the predictors of their increase. Subjects and Methods This was a retrospective, observational study. The medical records of patients who had undergone bariatric surgery at a tertiary care hospital between January 2007 and March 2015 were reviewed. Patients who underwent revisional surgery or were treated with fibrates were excluded from the analysis. Results A total of 185 patients were included in the study. Follow-up rates were as follows: 87% (year 2) and 28% (year 5). At postoperative month 3, HDLc levels decreased significantly versus baseline (- 11.1%; p = 0.000), at which point they began to rise, reaching their maximum level 2 years after bariatric surgery (26.2% increase from baseline; p = 0.000). The increase in HDLc concentration 2 years after surgery correlated with the preoperative HDLc level (r = - 0.292, p = 0.001), and it was greater in patients who underwent sleeve gastrectomy versus gastric bypass (0.36 +/- 0.4 vs. 0.18 +/- 0.4 mmol/L, respectively; p = 0.018). Conclusion Bariatric surgery has a beneficial effect on HDLc levels. The maximum increase in postoperative HDLc concentrations is observed 2 years after surgery. Preoperative HDLc and the type of surgery are both significant predictors of the maximum increase in HDLc levels.