Effects of sleeve gastrectomy in neonatally streptozotocin-induced diabetic rats

State of art on the mechanisms of laparoscopic sleeve gastrectomy in treating type 2 diabetes mellitus

Obesity and type-2 diabetes mellitus (T2DM) are metabolic disorders. Obesity increases the risk of T2DM, and as obesity is becoming increasingly common, more individuals suffer from T2DM, which poses a considerable burden on health systems. Traditionally, pharmaceutical therapy together with lifestyle changes is used to treat obesity and T2DM to decrease the incidence of comorbidities and all-cause mortality and to increase life expectancy. Bariatric surgery is increasingly replacing other forms of treatment of morbid obesity, especially in patients with refractory obesity, owing to its many benefits including good long-term outcomes and almost no weight regain. The bariatric surgery options have markedly changed recently, and laparoscopic sleeve gastrectomy (LSG) is gradually gaining popularity. LSG has become an effective and safe treatment for type-2 diabetes and morbid obesity, with a high cost-benefit ratio. Here, we review the me-chanism associated with LSG treatment of T2DM, and we discuss clinical studies and animal experiments with regard to gastrointestinal hormones, gut microbiota, bile acids, and adipokines to clarify current treatment modalities for patients with obesity and T2DM.

The Effects of Sleeve Gastrectomy on Glucose Metabolism and Glucagon-Like Peptide 1 in Goto-Kakizaki Rats

PURPOSE

To investigate the effects of sleeve gastrectomy (SG) on glucose metabolism and changes in glucagon-like peptide 1 (GLP-1) in Goto-Kakizaki (GK) rats.

METHODS

GK rats were randomly assigned to one of three groups: SG, SG pair-fed plus sham surgery (PF-sham), and ad libitum-fed no surgery (control). Food intake, body weight, blood glucose, GLP-1 and insulin levels, and GLP-1 expression in the jejunum and ileum were compared.

RESULTS

The SG rats exhibited lower postoperative food intake, body weight, and fasting glucose than did the control rats (P < 0.05). SG significantly improved glucose and insulin tolerance (P < 0.05). Plasma GLP-1 levels were higher in SG rats than in control or PF-sham rats in the oral glucose tolerance test (OGTT) (P < 0.05). Blood glucose levels expressed as a percentage of baseline were higher in SG rats than in control rats after exendin (9-39) administration (P < 0.05). The levels of GLP-1 expression in the jejunum and ileum were higher in SG rats than in PF-sham and control rats (P < 0.05).

CONCLUSIONS

Improvement of glucose metabolism by SG was associated with increased GLP-1 secretion. SG contributes to an increase in plasma GLP-1 levels via increased GLP-1 expression in the mucosa of the jejunum and/or ileum.

Effects of sleeve gastrectomy and ileal transposition, alone and in combination, on food intake, body weight, gut hormones, and glucose metabolism in rats

Bariatric surgeries are hypothesized to produce weight loss and improve diabetes control by multiple mechanisms including gastric restriction and lower gut stimulation; the relative importance of these mechanisms remains poorly understood. We compared the effects of a typical foregut procedure, sleeve gastrectomy, (SG) with a primarily hindgut surgery, ileal transposition (IT), alone and together (SGIT), or sham manipulations, on food intake, body weight, gut hormones, glucose tolerance, and key markers of glucose homeostasis in peripheral tissues of adult male Sprague-Dawley rats (450-550 g, n = 7-9/group). SG, IT, and SGIT surgeries produced transient reduction in food intake and weight gain; the effects of SG and IT on intake and body weight were nonadditive. SG, IT, and SGIT surgeries resulted in increased tissue expression and plasma concentrations of the lower gut hormones glucagon-like peptide-1 and peptide YY and decreased plasma glucose-dependent insulinotropic peptide, insulin, and leptin concentrations. Despite transient effects on intake and weight gain, the SG, IT, and SGIT surgeries produced a significant improvement in glucose tolerance. In support of glycemic improvements, the protein abundance of key markers of glucose metabolism (e.g., GLUT4, PKA, IRS-1) in muscle and adipose tissue were increased, whereas the expression of key gluconeogenic enzyme in liver (G-6-Pase) were decreased following the surgeries. Therefore, our data suggest that enhanced lower gut stimulation following SG, IT, and SGIT surgeries leads to transient reduction in food intake and weight gain together with enhanced secretion of lower gut hormones and improved glucose clearance by peripheral tissues.

All bariatric surgeries are not created equal: insights from mechanistic comparisons

Despite considerable scientific progress on the biological systems that regulate energy balance, we have made precious little headway in providing new treatments to curb the obesity epidemic. Diet and exercise are the most popular treatment options for obesity, but rarely are they sufficient to produce long-term weight loss. Bariatric surgery, on the other hand, results in dramatic, sustained weight loss and for this reason has gained increasing popularity as a treatment modality for obesity. At least some surgical approaches also reduce obesity-related comorbidities including type 2 diabetes and hyperlipidemia. This success puts a premium on understanding how these surgeries exert their effects. This review focuses on the growing human and animal model literature addressing the underlying mechanisms. We compare three common procedures: Roux-en-Y Gastric Bypass (RYGB), vertical sleeve gastrectomy (VSG), and adjustable gastric banding (AGB). Although many would group together VSG and AGB as restrictive procedures of the stomach, VSG is more like RYGB than AGB in its effects on a host of endpoints including intake, food choice, glucose regulation, lipids and gut hormone secretion. Our strong belief is that to advance our understanding of these procedures, it is necessary to group bariatric procedures not on the basis of surgical similarity but rather on how they affect key physiological variables. This will allow for greater mechanistic insight into how bariatric surgery works, making it possible to help patients better choose the best possible procedure and to develop new therapeutic strategies that can help a larger portion of the obese population.

Type 2 diabetes in obese patients with body mass index of 30-35 kg/m2: sleeve gastrectomy versus medical treatment

BACKGROUND

Type 2 diabetes mellitus (T2DM) and obesity are diseases of epidemic proportions. Long-term realistic weight loss by nonsurgical methods has a variable effect on glycemic control, and only a proportion of patients with T2DM have a worthwhile response. Laparoscopic sleeve gastrectomy (LSG) has been proposed as an advantageous bariatric procedure for patients with a lower body mass index (BMI). Our objective was to compare the effects of LSG and medical therapy on patients with T2DM and a BMI of <35 kg/m(2).

METHODS

A total of 18 nonmorbidly obese patients with T2DM, diagnosed according to the American Diabetes Association guidelines, were consecutively enrolled. Of these patients, 9 underwent LSG (group A) and 9 underwent conventional medical therapy (group B). The 2 groups were matched for BMI, glycated hemoglobin (HbA1c) and C-peptide levels, pretrial therapy type, and number of patients with a T2DM duration of >10 years.

RESULTS

In group A, T2DM resolution was achieved in 8 (88.8%) of the 9 patients (T2DM duration 5.2 yr). Hypertension was controlled in all 8 of 9 patients. Dyslipidemia was corrected. In 1 patient, obstructive sleep apnea syndrome improved. In group B, all 9 patients continued to have T2DM and required hypertensive and hypolipemic therapies throughout the observation period. At baseline, 3 patients were affected by obstructive sleep apnea syndrome and remained affected 1 year later.

CONCLUSION

The results of the present study have confirmed the efficacy of LSG in the treatment of nonmorbidly obese T2DM patients, with a remission rate of 88.8% without undesirable excessive weight loss. The results in this group of patients add to those obtained by us in patients with a BMI >35 kg/m(2).