Background

Laparoscopic sleeve gastrectomy (LSG) has surpassed Roux-en-Y gastric bypass (RYGB) as the most prevalent bariatric procedure worldwide. While LSG and RYGB demonstrate equivalent short-term weight loss, long-term weight loss tends to be greater after RYGB.Differences in the effect of these procedures on gut hormones that regulate energy homeostasis are felt to partially underlie differences in outcomes.The objective of this study was to quantify blood levels of GI tract hormones of energy homeostasis at one year follow up to delineate possible reasons for greater efficacy of RYGB over LSG in achieving weight loss.

Methods

Patients undergoing LSG (n=19) and RYGB (n=40) were studied before surgery and at 2,12, 26, and 52 weeks postoperatively.Fasting and postprandial blood samples were assayed at baseline, 26, and 52 weeks for PYY, ghrelin and GLP-1.Fasting and postprandial appetitive sensations were assessed by visual analog scale.

Results

At 1 year there was greater weight loss in RYGB compared with LSG patients (30% vs 27%; p=0.03).At 52 weeks area under the curve (AUC) for PYY was greater in RYGB patients (p=.0004).RYGB patients had significant increases in GLP-1 AUC compared to baseline (p=.002).Ghrelin levels decreased only after LSG compared to baseline (p=.03) but were not significantly different from RYGB.There was a trend toward decreased sweet cravings in RYGB patients (p=.057).

Conclusions

Differences in GI-tract hormones that regulate energy homeostasis and changes in sweet cravings are possible mechanisms for greater efficacy of RYGB compared to LSG.