Laparoscopic Roux-en-Y gastric bypass vs. laparoscopic sleeve gastrectomy for morbid obesity: a systematic review and meta-analysis of lipid effects at one year postsurgery.

INTRODUCTION: Results of the effects of Roux-en-Y gastric bypass (GB) and sleeve gastrectomy (SG) on triglyceride and high-density lipoprotein (HDL) cholesterol levels are controversial. Moreover, previous meta-analyses focused on global dyslipidemia remission, but did not include the separate remission rates of the different lipid fractions. Hence, the aim of the present meta-analysis was to compare the outcomes (concentration change and remission rates) of GB and SG on diverse lipid disorders one year postbariatric surgery (BS).

EVIDENCE ACQUISITION: An exhaustive electronic search carried out on MedLine, Embase and The Cochrane Central Register of Controlled Trials (Central) until July 2016 yielded 2621 records, of which 17, totaling 4699 obese patients with one-year follow-up after BS were included in the meta-analysis.

EVIDENCE SYNTHESIS: GB was superior to SG in terms of total cholesterol (mean difference= 19.77 mg/dL, 95% CI: 11.84-27.69) and low-density lipoprotein (LDL) cholesterol (mean difference: 19.29 mg/dL, 95% CI: 11.93-26.64) decreases as well as in hypercholesterolemia remission (RR: 1.43, 95% CI: 1.27-1.61). No differences were found between GB and SG in terms of HDL cholesterol increase or triglyceride concentration change after surgery, as well as in hypertriglyceridemia and low HDL remission rates.

CONCLUSIONS: The effect of GB on total and LDL cholesterol concentration decreases and remission was greater than that of SG, whereas no differences were observed with respect to HDL cholesterol and triglyceride concentration evolution. Conclusions cannot be drawn from hypertriglyceridemia and low HDL remission rates based on this meta-analysis.