Effect of Roux-en-Y gastric bypass vs sleeve gastrectomy on glucose and gut hormones: a prospective randomised trial

BACKGROUND

Laparoscopic Roux-en-Y gastric bypass (LRYGB) is the most common bariatric technique. Laparoscopic sleeve gastrectomy (LSG) is a restrictive procedure; the metabolic and endocrine effects of which remain unknown. We compared the effects of both procedures on glucose metabolism and fasting and meal-stimulated gut hormone levels.

METHODS

Seven patients were randomised to LRYGB and eight to LSG. All patients were evaluated before and at 3 and 12 months postoperatively. Plasma levels of glucose, insulin, ghrelin, leptin, peptide YY (PYY), GLP-1 and pancreatic polypeptide were measured before and after 10 and 60 min of a standard test meal ingestion.

RESULTS

Age, body mass index and preoperative hormone levels were similar in both groups. A significant reduction of plasma glucose and insulin levels was observed after surgery. Moreover, a normalisation of homeostatic model assessment for insulin resistance value was also seen after both procedures. The fasting and postprandial leptin levels were significantly lower in the LRYGB group. LSG was followed by a significant reduction in fasting ghrelin levels. In the LRYGB group, GLP-1 levels increased significantly after the test meal.

CONCLUSIONS

LRYGB and LSG markedly improved glucose homeostasis. Only LSG decreased fasting and postprandial ghrelin levels, whereas GLP-1 and PYY levels increased similarly after both procedures.

[Bone mass loss after sleeve gastrectomy: a prospective comparative study with gastric bypass]

INTRODUCTION

Bariatric surgery is the most effective option for the treatment of patients with a high risk of complications due to their obesity. However, it brings about a series of changes in calcium and vitamin D metabolism and an increase in resorption which lead to a loss of bone mass.

AIM

The objective of this study is to compare sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) as regards loss of bone mass using bone densitometry and bone remodelling markers.

PATIENTS AND METHODS

Fifteen women with morbid obesity were included, 8 by SG and 7 by RYGB, with a mean age of 47.8+/-9 and mean body mass index 43.3+/-3.4. Bone mass measurements were made on the lumbar spine, femur and distal radius, and the bone remodelling markers N-telopeptide (NTx) and bone alkaline phosphatase (BALP), as well as vitamin D levels before and 12 months after surgery.

RESULTS

A significant bone mass loss was observed was observed with SG and RYGB, in the lumbar spine and hip, whilst no differences were observed in the radial. The percentage bone mass loss was less in the column and femur after SG than with RYGB, although it did not reach statistical significance, 4.6%+/-4.4 (mean+/-SD) and 6.3%+/-5.4 (mean+/-SD), respectively. At 12 months the Ntx increased for both types of surgery, and the BAP was only increased for SG.

CONCLUSION

SG causes less, although not significant, bone mass loss compared to RYGB.