Improvements in cholesterol efflux capacity of HDL after bariatric surgery in patients with obesity: a meta-analysis

Bariatric surgery can decrease cardiovascular risk because of its effects on atherosclerotic cardiovascular disease (ASCVD) risk factors such as dyslipidemia, diabetes mellitus, and hypertension. It has been hypothesized that lipoprotein biomarkers related to low-density lipoproteins (LDL) and high-density lipoproteins (HDL) as well as their subfractions and macrophage cholesterol efflux capacity (CEC) might be important in cardiovascular risk assessment. The aim of this systematic review and meta-analysis was to evaluate the CEC of HDL as a negative risk factor for ASCVD in individuals with obesity following bariatric surgery. PubMed, Scopus, Web of Science and Scholar were searched from inception to May, 2024. Clinical studies that reported CEC data with a follow-up after bariatric surgery were eligible for meta-analysis. Two independent reviewers extracted data and assessed the risk of bias. Among the 55 articles identified, 8 studies measuring cholesterol efflux capacity (CEC) after bariatric surgery were analyzed. Four studies indicated a nonsignificant increase in total CEC after Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) (SMD: 0.361, p = 0.256). Five studies showed a significant reduction in ABCA1-dependent CEC after the surgery (SMD: -1.044, 95% CI: -1.916, -0.173, p = 0.019). In contrast, five studies reported a significant increase in ABCA1-independent CEC (SMD: 0.932, 95% CI: 0.142, 1.722, p = 0.021). Subgroup analyses showed that total CEC varied by type of surgery, with significant increases for SG (SMD: 0.748, p < 0.001) but not for RYGB (SMD: -0.341, p = 0.650). ABCA1-dependent CEC decreased significantly after RYGB (SMD: -1.545, p = 0.015), while no significant changes were observed for ABCA1-independent CEC after both types of surgery. Bariatric surgery, particularly SG, is associated with clinically significant increase in total post-surgery CEC which might be beneficial concerning the ASCVD risk.