Bariatric surgery improves lipoprotein profile in morbidly obese patients by reducing LDL cholesterol, apoB, and SAA/PON1 ratio, increasing HDL cholesterol, but has no effect on cholesterol efflux capacity

Abstract

Bariatric surgery has been shown to reduce cardiovascular events and cause-specific mortality for coronary artery disease in obese patients. Lipoprotein biomarkers relating to low-density lipoprotein (LDL), high-density lipoprotein (HDL), their subfractions, and macrophage cholesterol efflux have all been hypothesized to be of value in cardiovascular risk assessment. The objective of this study was to examine the effect of a lifestyle intervention followed by bariatric surgery on the lipid profile of morbidly obese patients. Thirty-four morbidly obese patients were evaluated before and after lifestyle changes and then 1 year after bariatric surgery. They were compared with 17 lean subjects. Several lipoprotein metrics, serum amyloid A (SAA), serum paraoxonase-1 (PON1), and macrophage cholesterol efflux capacity (CEC) were assessed. Average weight loss after the lifestyle intervention was 10.5% and 1 year after bariatric surgery was 33.9%. The lifestyle intervention significantly decreased triglycerides (TGs; -28.7mg/dL, P<.05), LDL cholesterol (LDL-C; -32.3mg/dL, P<.0001), and apolipoprotein B (apoB; -62.9μg/mL, P<.001). Bariatric surgery further reduced TGs (-36.7mg/dL, P<.05), increased HDL cholesterol (+12mg/dL, P<.0001), and reductions in LDL-C and apoB were sustained. Bariatric surgery reduced large, buoyant LDL (P<.0001), but had no effect on the small, dense LDL. The large HDL subfractions increased (P<.0001), but there was no effect on the smaller HDL subfractions. The ratio for SAA/PON1 was reduced after the lifestyle intervention (P<.01) and further reduced after bariatric surgery (P<.0001). Neither the lifestyle intervention nor bariatric surgery had any effect on CEC. Lifestyle intervention followed by bariatric surgery in 34 morbidly obese patients showed favorable effects on TGs, LDL-C, and apoB. HDL cholesterol and apoA1 was increased, apoB/apoA1 ratio as well as SAA/PON1 ratio reduced, but bariatric surgery did not influence CEC.