Sleeve gastrectomy: the ideal option for metabolic surgery?

Changes in insulin sensitivity and secretion after sleeve gastrectomy

Background

Sleeve gastrectomy is indicated for the treatment of obesity and related co-morbidity including diabetes. The dynamic changes in insulin secretion and sensitivity after sleeve gastrectomy are unknown.

Methods

Whole-body insulin sensitivity was measured by the euglycaemic hyperinsulinaemic clamp technique, and insulin secretion by C-peptide deconvolution after an oral glucose tolerance test (OGTT), before and 3, 6 and 12 months after sleeve gastrectomy in morbidly obese subjects. The time course of glucagon-like peptide (GLP) 1, as a marker of insulin secretion following OGTT, was also assessed.

Results

Ten patients were included in the study. Median (range) baseline insulin sensitivity (M-value) increased from 84·0 (20·2–131·4) mmol per kg per min at baseline to 122·8 (99·0–179·3) mmol per kg per min at 12 months after surgery (P = 0·015). Fasting insulin sensitivity, measured by homeostatic model assessment of insulin resistance, which represents a surrogate index of hepatic insulin resistance, decreased from 3·3 (1·9–5·5) to 0·7 (0·5–1·1) mg/dl·µunits/ml (P < 0·001). Total insulin secretion, measured as incremental area under the curve (AUC), after OGTT decreased from 360·4 (347·9–548·0) to 190·1 (10·1–252·0) mmol/l·180 min at 12 months (P = 0·011). The AUC for GLP-1 increased from 258·5 (97·5–552·6) to 5531·8 (4143·0–7540·9) pmol/l·180 min at 12 months after sleeve gastrectomy (P < 0·001). In multiple regression analysis, 51 per cent of the M-value variability was explained by GLP-1 secretion.

Conclusion

Sleeve gastrectomy improved insulin sensitivity and reduced insulin secretion within 6 months after surgery. Although there was a correlation between insulin sensitivity and bodyweight, the major driver of the improvement in insulin sensitivity was GLP-1 secretion.

Early Endocrine and Metabolic Changes After Bariatric Surgery in Grade III Morbidly Obese Patients: A Randomized Clinical Trial Comparing Sleeve Gastrectomy and Gastric Bypass

BACKGROUND

We compared the early endocrine and metabolic changes associated with sleeve gastrectomy (SG) and gastric bypass (GB) in grade III obese patients.

METHODS

Fifty morbidly obese patients were randomized into two groups on the basis of their position in the queue-group A comprised SG and group B was GB. Comparison between the two groups was based on clinical and laboratory variables such as fasting blood glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), glycated hemoglobin (HbA1c), lipids, albumin, and ferritin. Patients were assessed after 7, 14, 30, 60, and 90 days and additional laboratory tests were done on the 90(th) day.

RESULTS

The following mean values were recorded for groups A and B, respectively: Age (years), 36.4 and 31.1; weight (kg), 123.2 and 128.3; and body mass index (BMI; kg/m(2)), 45.6 and 47.3. In the first postoperative week, group B showed a greater weight loss (P=0.047) that was not observed after 14, 30, 60, and 90 days (P>0.05). Group A had an average excess weight loss of 31.09 kg compared to 32.69 kg in group B (P=0.222). Glycemic control was better in group B (P=0.023), whereas the control of systemic arterial pressure was better in group A (P=0.026). There were no significant differences in early lipid control and micronutrient deficiencies between the two groups.

CONCLUSIONS

SG and GB were equally effective in promoting weight loss after 90 days. However, whereas SG was associated with better early remission rates for hypertension, GB was more effective in fasting blood glucose control but not in HOMA-IR and HbA1c levels. There was no difference in the protein or vitamin deficiencies of the two groups.