Temporal changes in glucose and insulin homeostasis after biliopancreatic diversion and laparoscopic adjustable gastric banding

A 9 years comparison of weight loss, disappearance of obesity, and resolution of diabetes mellitus with biliointestinal bypass and with adjustable gastric banding: experience of a collaborative network

AIMS

Long-term comparisons between bariatric surgical techniques have been performed for gastric bypass (RYGB), sleeve gastrectomy (LSG), and biliopancreatic diversion (BPD) vs gastric banding (LAGB), but short-term studies (6 months-4 years) have only compared biliointestinal bypass (BIBP) and LAGB. The participating institutions regularly perform both BIBP and LAGB with a common protocol, and the aim of this retrospective study was to compare long-term effects of the two procedures on body weight, on clinical and metabolic variables, and on resolution of obesity and of diabetes.

METHODS

All procedures performed between 01/01/1998 and 31/12/2005 were considered; 73 out of 91 patients undergoing BIBP, and 154 out of 249 patients undergoing LAGB were evaluable up to 9 years.

RESULTS

BIBP was significantly more effective than LAGB in terms of weight loss and of resolution of obesity (BMI < 30 kg/m²), in terms of decrease of systolic blood pressure and of serum cholesterol, and similar in terms of resolution of diabetes. In addition, the effect of BIBP was stable, while the effect of LAGB decreased with time.

CONCLUSIONS

Both BIBP and LAGB exert long-term effects on body weight, on blood pressure, and on resolution of diabetes mellitus; the effect of BIBP is significantly greater than the effect of LAGB in terms of weight loss, resolution of obesity, of control of systolic blood pressure and of serum cholesterol, but not in terms of resolution of diabetes.

Neuroendocrine regulation of energy balance: Implications on the development and surgical treatment of obesity

INTRODUCTION

Obesity, a serious public health problem, occurs mainly when food consumption exceeds energy expenditure. Therefore, energy balance depends on the regulation of the hunger-satiety mechanism, which involves interconnection of the central nervous system and peripheral signals from the adipose tissue, pancreas and gastrointestinal tract, generating responses in short-term food intake and long-term energy balance. Increased body fat alters the gut- and adipose-tissue-derived hormone signaling, which promotes modifications in appetite-regulating hormones, decreasing satiety and increasing hunger senses. With the failure of conventional weight loss interventions (dietary treatment, exercise, drugs and lifestyle modifications), bariatric surgeries are well-accepted tools for the treatment of severe obesity, with long-term and sustained weight loss. Bariatric surgeries may cause weight loss due to restriction/malabsorption of nutrients from the anatomical alteration of the gastrointestinal tract that decreases energy intake, but also by other physiological factors associated with better results of the surgical procedure.

OBJECTIVE

This review discusses the neuroendocrine regulation of energy balance, with description of the predominant hormones and peptides involved in the control of energy balance in obesity and all currently available bariatric surgeries.

CONCLUSIONS

According to the findings of our review, bariatric surgeries promote effective and sustained weight loss not only by reducing calorie intake, but also by precipitating changes in appetite control, satiation and satiety, and physiological changes in gut-, neuro- and adipose-tissue-derived hormone signaling.

Insulin Sensitivity and Secretion in Obese Type 2 Diabetic Women after Various Bariatric Operations

OBJECTIVE

To compare the effects of biliopancreatic diversion (BPD) and laparoscopic gastric banding (LAGB) on insulin sensitivity and secretion with the effects of laparoscopic gastric plication (P).

METHODS

A total of 52 obese women (age 30-66 years) suffering from type 2 diabetes mellitus (T2DM) were prospectively recruited into three study groups: 16 BPD; 16 LAGB, and 20 P. Euglycemic clamps and mixed meal tolerance tests were performed before, at 1 month and at 6 months after bariatric surgery. Beta cell function derived from the meal test parameters was evaluated using mathematical modeling.

RESULTS

Glucose disposal per kilogram of fat free mass (a marker of peripheral insulin sensitivity) increased significantly in all groups, especially after 1 month. Basal insulin secretion decreased significantly after all three types of operations, with the most marked decrease after BPD compared with P and LAGB. Total insulin secretion decreased significantly only following the BPD. Beta cell glucose sensitivity did not change significantly post-surgery in any of the study groups.

CONCLUSION

We documented similar improvement in insulin sensitivity in obese T2DM women after all three study operations during the 6-month postoperative follow-up. Notably, only BPD led to decreased demand on beta cells (decreased integrated insulin secretion), but without increasing the beta cell glucose sensitivity.

Metabolic surgery: action via hormonal milieu changes, changes in bile acids or gut microbiota? A summary of the literature

Obesity and type 2 diabetes remain epidemic problems. Different bariatric surgical techniques causes weight loss and diabetes remission to varying degrees. The underlying mechanisms of the beneficial effects of bariatric surgery are complex, and include changes in diet and behaviour, as well as changes in hormones, bile acid flow, and gut bacteria. We summarized the effects of multiple different bariatric procedures, and their resulting effects on several hormones (leptin, ghrelin, adiponectin, glucagon-like peptide 1 (GLP-1), peptide YY, and glucagon), bile acid changes in the gut and the serum, and resulting changes to the gut microbiome. As much as possible, we have tried to incorporate multiple studies to try to explain underlying mechanistic changes. What emerges from the data is a picture of clear differences between restrictive and metabolic procedures. The latter, in particular the roux-en-Y gastric bypass, induces large and distinctive changes in most measured fat and gut hormones, including early and sustained increase in GLP-1, possible through intestinal bile acid signalling. The changes in bile flow and the gut microbiome are causally inseparable so far, but new studies show that each contributes to the effects of weight loss and diabetes resolution.