The Effect of Bariatric Surgery on Circulating Levels of Oxidized Low‐Density Lipoproteins Is Apparently Independent of Changes in Body Mass Index: A Systematic Review and Meta‐Analysis

Abstract

Background. Obesity is related to dyslipidemia and increased circulating oxidated LDL (ox-LDL) concentrations that may predispose to atherosclerosis. Bariatric surgery may lower the risk of cardiovascular mortality. Elevated plasma ox-LDL has been associated with atherogenesis and atherosclerotic cardiovascular disease (ASCVD) events. The aim of this meta-analysis was to investigate the impact of bariatric surgery on proatherogenic circulating ox-LDL levels in patients with severe obesity. Methods. Four databases were systematically searched from inception to May 1, 2021. Also, to clarify the heterogeneity of studies with regard to treatment duration, research design, and the demographic features, a random-effects model and the generic inverse variance weighting approach were utilized. To determine the association with the estimated effect size, a random-effect meta-regression approach was performed. Finally, a meta-regression analysis was conducted to explore the influence of, respectively, baseline and changes in body mass index (BMI), baseline ox-LDL, and postsurgery follow-up period with the estimated effect size of surgery on ox-LDL levels. Results. Meta-analysis of 11 studies including 470 subjects showed a significant decline in circulating ox-LDL following bariatric surgery (SMD: -0.971, 95% CI: -1.317, -0.626, p < 0.001 , I 2 : 89.43%). The results of meta-regression did not show any significant association between the changes in ox-LDL after bariatric surgery and baseline BMI, duration of follow-up or baseline ox-LDL values. However, there was a significant association between ox-LDL alteration and percentage of BMI change. Conclusion. Bariatric surgery in patients who had severe obesity causes a decrease of circulating ox-LDL that was apparently dependent in BMI changes.

Impact of bariatric surgery on circulating PCSK9 levels as marker of cardiovascular disease risk: a meta-analysis

“…This is the first meta-analysis evaluating the impacts of bariatric surgery on PCSK9 as a regulator of plasma cholesterol levels. This finding is consistent is with other reports suggesting a positive impact of bariatric surgery on cardiovascular risk factors (17)(18)(19)(20). The observed drop in circulating PCSK9 levels could be attributed to long-term weight loss caused by bariatric procedure as well as sustained decreases in total food intake (11).…”

Effect of Bariatric Surgery on Flow-Mediated Vasodilation as a Measure of Endothelial Function: A Systematic Review and Meta-Analysis

“…The results reported here are in accordance with a limited meta-analysis of eight studies that reported an improvement in FMD after surgery [ 15 ] within a 12-month period. It is well recognized that cardiovascular risk parameters improve following bariatric surgery [ 3 , 53 ], and one of these parameters would be the improvement in endothelial cell function that is reflected in the increase in FMD [ 13 ]. Furthermore, in another meta-analysis evaluating the impact of bariatric surgery on cardiovascular risk, we showed that pulse wave velocity (PWV), as a measure of arterial stiffness, favorably predicts subsequent cardiovascular outcomes [ 12 ].…”

Lipid Peroxidation in Obesity: Can Bariatric Surgery Help?

“…A study about Swedish adjustable gastric band surgery showed that the postoperative BMI and concentrations of lipid, malondialdehyde (MDA), and oxLDL decreased significantly [ 92 ]. Following bariatric surgery, the changes in circulating levels of oxLDL strongly correlate with the change in BMI (%) [ 93 ]. Oxidative stress indicators in plasma levels of patients after RYGB procedure showed that MDA was reduced, while GSH and total radical antioxidant parameter were increased, suggesting a drop in oxidative stress and improvement in antioxidant protection [ 94 ].…”