Sleeve gastrectomy provides a better control of diabetes by decreasing ghrelin in the diabetic Goto-Kakizaki rats

Weight and Glucose Control in Rats Submitted to Sleeve Gastrectomy with Cafeteria Diet-Induced Obesity

Introduction: Sleeve gastrectomy (SG) has been widely disseminated as a surgical treatment for obesity and associated comorbidities, and currently it is one of the most performed surgeries in the world. Experimental research is becoming increasingly relevant to characterize the pathophysiological mechanisms induced by it. Objective: The aim of this study was to standardize an experimental model of SG in rats with obesity induced using a cafeteria diet (CAF) and evaluate variations in weight and glycemic control after vertical SG, maintaining the CAF. Materials and Methods: Twenty Rattus norvegicus albinus rats, Wistar strain, with an average weight of 250 g were used. The animals were randomized into two groups and underwent 4 weeks of obesity induction before the procedure. In 10 animals of the SG group, vertical SG was performed, and in 10 animals of the control/sham (C) group, simulated surgery was performed, consisting of laparotomy and bidigital compression of the stomach. The animals were followed for a total of 8 weeks, with the weight assessed weekly and fasting blood glucose assessed before the start of the CAF, at the time of surgery, and after 4 weeks of the postoperative period, when they were sacrificed. Results: Before obesity induction, the average weight was 257.8 g in the SG group 266.1 g in the C group. After obesity induction, the average weight was 384 g in the vertical sleeve gastrectomy group and 374.8 g in the C group. In the fourth postoperative week, the average weight was 391.6 g in the VSG group and 436.6 g in the C group. The average blood glucose levels were 88.7, 101.8, and 91.3 mg/dL in the VSG group and 86.6, 103.1, and 109.4 mg/dL in the C group, respectively, before the start of the diet, in the fourth preoperative week, and in the fourth postoperative week. Conclusions: Vertical SG in rats is feasible and promotes glycemic control in the postoperative period. CAF allows induction of obesity and changes in blood glucose.

Sleeve Gastrectomy Attenuates Diabetic Nephropathy by Upregulating Nephrin Expressions in Diabetic Obese Rats

PURPOSE

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease, and sleeve gastrectomy (SG) is considered to be an effective strategy to improve pre-existing DN. However, the mechanism remains unknown.

MATERIALS AND METHODS

Animal model of DN was induced by high-fat diet (HFD) and streptozotocin (STZ). SG or sham surgery was performed and rats were sacrificed at 4, 8, and 12 weeks after surgery. The basic parameters (blood glucose, body weight, kidney weight), indicators of renal function including serum creatinine (Scr), blood urea nitrogen (BUN), urine microalbumin, urine creatinine (Ucr), microalbumin creatinine ratio (UACR), ultrastructural changes of glomerulus, and the expression of nephrin gene and protein in glomerular podocytes were compared among groups.

RESULTS

Blood glucose and body weight of SG rats were significantly lower than those of the sham-operated rats, and renal function of SG groups were also significantly improved within the postoperative period of 12 weeks. The results of periodic acid-Schiff staining (PAS) and transmission electron microscopy (TEM) showed that glomerular hypertrophy and accumulation of extracellular matrix proteins were significantly alleviated after SG, and the thickness of basement membrane and the fusion or effacement of foot processes were also significantly improved. The mRNA and protein expression of nephrin in SG groups was significantly higher than that in the sham group.

CONCLUSION

These results suggest that SG attenuates DN by upregulating the expression of nephrin and improving the ultrastructure of glomerular filtration membrane. This study indicates that SG can be used as an available therapeutic intervention for DN.

Sleeve Volume and Preoperative Gastric Volume Assessment Using Three-dimensional MDCT Gastrography and Their Correlation to Short-term Post-Sleeve Gastrectomy Weight Loss

PURPOSE

Several factors including preoperative stomach capacity and sleeve volume impact weight loss after laparoscopic sleeve gastrectomy (LSG). We aimed at measuring these volumes using multidetector computed tomography (MDCT) gastrography and correlating them with postoperative weight losses.

MATERIALS AND METHODS

Morbidly obese patients prepared for LSG during 2018 were included in the study. MDCT gastrography was performed 1 week before, 6 and 12 months after LSG. Preoperative gastric volume and postoperative sleeve volumes were measured. Correlation with preoperative BMI and postoperative %TWL was performed. The change in sleeve volume at 6 and 12 months was assessed.

RESULTS

A total of 98 patients (62 F) were included. Mean preoperative BMI was47 ± 7 kg/m². Follow-up was achieved in 89 patients (91%) and 82 patients (83%) at 6 and 12 months, respectively. Mean %TWL was 24 ± 3 and 32.8 ± 3 at 6 and 12 months, respectively (p < 0.05). Preoperative gastric volume ranged from 800 to 1800 ml (mean ± SD, 1310 ± 307) and dropped significantly to range from 140 to 170 ml (158 ± 9) and from 165 to 210 ml (181 ± 12) at 6 and 12 months postoperatively, respectively. Pouch was not significantly dilated at 12 vs. 6 months postoperatively. Preoperative gastric volume was significantly correlated with preoperative BMI (p = 0.006*) but not with postoperative weight losses. Correlation between postoperative pouch volumes and weight losses at 6 and 12 months postoperatively showed no significance.

CONCLUSION

Sleeve pouch is significantly smaller than preoperative stomach, but not significantly correlated to weight loss. Restriction is an important, but not the only factor controlling weight loss after LSG.

VERTICAL GASTRECTOMY VS. EXTENDED VERTICAL GASTRECTOMY: WHAT IS THE IMPACT ON GASTROESOPHAGEAL REFLUX DISEASE IN OBESE RATS?

BACKGROUND

Extended vertical gastrectomy is a variation of the vertical gastrectomy technique requiring studies to elucidate safety in relation to gastroesophageal reflux.

AIM

To analyze comparatively vertical gastrectomy (VG) and extended vertical gastrectomy (EVG) in rats with obesity induced by cafeteria diet in relation to the presence of reflux esophagitis, weight loss and macroscopic changes related to the procedures.

METHODS

Thirty Wistar rats were randomized into three groups, and after the obesity induction period by means of a 28-day cafeteria diet, underwent a simulated surgery (CG), VG and VGA. The animals were followed up for 28 days in the post-operative period, and after euthanasia, the reflux esophagitis evaluation was histopathologically performed. Weight and macroscopy were the other variables; weight was measured weekly and the macroscopic evaluation was performed during euthanasia.

RESULTS

All animals presented some degree of inflammation and the presence of at least one inflammation criterion; however, there was no statistically significant difference in the analysis among the groups. In relation to weight loss, the animals in CG showed a gradual increase during the whole experiment, evolving to super-obesity at the end of the study, while the ones with VG and EVG had weight regain after the first post-operative period; however, a less marked regain compared to CG, both for VG and EVG.

CONCLUSION

There is no difference in relation to reflux esophagitis VG and EVG, as well as macroscopic alterations, and both techniques have the ability to control the evolution of weight during postoperative period in relation to CG.

Gastric Plication and Sleeve Gastrectomy in an Experimental Model of Obesity: New Insights into Weight Loss, Intake and Metabolic Results

AIM

Laparoscopic gastric plication (LGP) is a bariatric surgical technique based on the anatomical principles of laparoscopic sleeve gastrectomy (LSG), but its effects on the metabolic profile are still uncertain. The aim of our study is to compare the changes in weight, metabolic parameters and gastric histology following intervention by gastric plication (GP) and sleeve gastrectomy (SG) in an experimental model of obesity.

METHODS

To conduct the study, 32 8-week-old male Sprague-Dawley rats (Charles River®) were fattened by means of a cafeteria diet and randomly assigned to the following experimental groups: group 1: GP (n = 12); group 2: SG (n = 12) and group 3: sham (n = 8).

RESULTS

Unlike the SG group, the GP group attained the weight of the sham group at the end of the experiment (week 16). The GP group continued to eat more cafeteria diet than the SG group. In addition, the SG group achieved better glycaemic control than the GP group. Significantly higher plasma ghrelin levels were observed at week 16 in the GP group than in the SG group (2.29 ± 0.5 vs 1.07 ± 0.4, p < 0.05), which also occurred for the glucagon plasmatic levels (62.71 ± 36.2 vs 24.63 ± 9.3, p < 0.05).

CONCLUSIONS

GP is not as effective as SG and cannot be considered a metabolic surgery due to observed hormonal variations. The animals subjected to a GP continued to have a high appetite for the cafeteria diet unlike the animals submitted to an SG. Hormonal mechanisms possibly related to glucagon and ghrelin may be involved in this metabolic response.

A Comparative Study of the Effect of Gastric Bypass, Sleeve Gastrectomy, and Duodenal-Jejunal Bypass on Type-2 Diabetes in non-Obese Rats

BACKGROUND

We compared the therapeutic effects of Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and duodenal-jejunal bypass (DJB) on type-2 diabetes mellitus (T2DM) in non-obese rats using clamp testing.

METHODS

Goto-Kakizaki rats (non-obese rats with T2DM) underwent surgery: RYGB, SG, or DJB. Rats were observed for 8 weeks after surgery to evaluate weight changes. Levels of glucose, insulin, and glucagon-like peptide (GLP)-1 were determined 2, 4, 6, and 8 weeks after surgery. An oral glucose tolerance test (OGTT) and clamp test was used to evaluate glucose tolerance and insulin resistance.

RESULTS

Rats in RYGB, SG, and DJB groups weighed significantly less than sham-group rats 6 and 8 weeks after surgery. Fasting blood glucose levels of RYGB, SG, and DJB rats were significantly lower than preoperative levels. One month after surgery, the area under the curve of the OGTT (in mmol•h/L) for RYGB, SG, DJB, and sham surgery groups was 38.9 ± 5.9, 50.9 ± 2.9, 46.8 ± 3.3, and 67.4 ± 6.0, respectively; there was no significant difference in glucose levels of SG and DJB groups. Glucose infusion rates (in mg/(kg•min)) were 18.3 ± 2.7, 17.2 ± 2.1, and 16.8 ± 1.9 in hyperinsulinemic-euglycemic-clamped RYGB, DJB, and SG rats, respectively, 8 weeks after surgery. The rate in the sham surgery group was 6.3 ± 0.9. Area under plasma insulin curves 8 weeks after surgery in hyperglycemic-clamped RYGB, DJB, SG, and sham surgery rats (in mU•h/L) were 98.8 ± 7.0, 84.4 ± 6.1, 89.0 ± 7.1, and 22.6 ± 2.6, respectively.

CONCLUSIONS

The three surgical methods described alleviated T2DM and reduced insulin resistance in non-obese rats with T2DM.

Is resected stomach volume related to weight loss after laparoscopic sleeve gastrectomy?

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) was initially performed as the first stage of biliopancreatic diversion with duodenal switch for the treatment of super-obese or high-risk obese patients but is now most commonly performed as a standalone operation. The aim of this prospective study was to investigate outcomes after LSG according to resected stomach volume.

METHODS

Between May 2011 and April 2013, LSG was performed in 102 consecutive patients undergoing bariatric surgery. Two patients were excluded, and data from the remaining 100 patients were analyzed in this study. Patients were divided into three groups according to the following resected stomach volume: 700-1,200 mL (group A, n = 21), 1,200-1,700 mL (group B, n = 62), and >1,700 mL (group C, n = 17). Mean values were compared among the groups by analysis of variance.

RESULTS

The mean percentage excess body weight loss (%EBWL) at 3, 6, 12, and 24 months after surgery was 37.68 ± 10.97, 50.97 ± 13.59, 62.35 ± 11.31, and 67.59 ± 9.02 %, respectively. There were no significant differences in mean %EBWL among the three groups. Resected stomach volume was greater in patients with higher preoperative body mass index and was positively associated with resected stomach weight.

CONCLUSIONS

Mean %EBWL after LSG was not significantly different among three groups of patients divided according to resected stomach volume. Resected stomach volume was significantly greater in patients with higher preoperative body mass index.

The effect of duodenojejunostomy and sleeve gastrectomy on type 2 diabetes mellitus and gastrin secretion in Goto-Kakizaki rats

BACKGROUND

Bariatric surgery is a highly effective treatment of type 2 diabetes in patients with morbid obesity. The weight-loss independent improvement of glycemic control observed after these procedures has led to the discussion whether bariatric surgery can be introduced as treatment for type 2 diabetes in patients with a body mass index < 35 kg/m(2). We have studied the effects of two bariatric procedures on type 2 diabetes and on gastrointestinal hormone secretion in a lean diabetic animal model.

METHODS

Male Goto-Kakizaki rats, 17-18 weeks old, were randomized into three groups: duodenojejunostomy (DJ), sleeve gastrectomy (SG), or sham operation. During 36 postoperative weeks we evaluated body weight, fasting blood glucose, glucose tolerance, insulin, HbA1c, glucagon-like peptide 1, cholesterol parameters, triglycerides, total ghrelin, and gastrin.

RESULTS

Oral glucose tolerance was significantly improved for both DJ and SG at four weeks after surgery (p < 0.05). At the 34th postoperative week, SG had significantly lower area under the curve during oral glucose tolerance test compared to sham (p = 0.007). SG had significantly lower HbA1c compared to sham at 12 weeks; (mean ± SEM) 4.3 ± 0.1 % versus 5.2 ± 0.3 % (p < 0.05) and compared to both DJ and sham 34 weeks after surgery [median (75 %;25 %)] 5.2 (6.0; 4.3) % versus 7.0 (7.5; 6.7) % and 7.3 (7.6; 6.7) % (p = 0.009). Serum gastrin levels were markedly elevated for SG compared to DJ and sham; 188.0 (318.0; 121.0) versus 77.5 (114.0; 58.0) and 68.0 (90.0; 59.5) pmol/L (p = 0.004) at six weeks and 192.0 (587.8; 110.8) versus 65.5 (77.0; 59.0) and 69.5 (113.0; 55.5) (p = 0.001) 36 weeks after surgery.

CONCLUSION

Sleeve gastrectomy induces hypergastrinemia, lowers HbA1c, and improves glycemic control in Goto-Kakizaki rats. Sleeve gastrectomy is superior to duodenojejunostomy as treatment of type 2 diabetes mellitus in this animal model.

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.

The effects of sleeve gastrectomy on hormonal regulation of glucose metabolism in Goto-Kakizaki rats

BACKGROUND

The antidiabetic effect of sleeve gastrectomy (SG) has been interpreted as a conceivable result of surgically induced weight loss in the obese type 2 diabetes mellitus (T2DM) subjects. However, the blood glucose control often occurs within days, before significant weight loss has been reached. This work aims to investigate the major mechanism and persistence regarding how SG improves glucose metabolism in nonobese T2DM rats.

METHODS

These Goto Kakizaki rats (n = 21) were randomly assigned into three groups: SG, sham SG, and pair-fed (PF) group, whose weight, food intake, oral glucose tolerance test, insulin tolerance test, plasma insulin, homeostasis model assessment for insulin resistance (HOMA-IR), ghrelin, and glucagon-like peptide-1 (GLP-1) were measured.

RESULTS

According to the experiment, from the 2nd week until the 24th week, the fasting blood glucose of the rats in the SG group had significantly decreased with the improved glucose tolerance. At the 2nd week postoperation, the area under the blood glucose concentration curve (AUC) received a distinct reduction of 28.1 % (P < 0.0001). The ghrelin secretion of the SG group was significantly decreased (P < 0.005). The GLP-1 had increased (P < 0.0001), while the HOMA-IR values decreased (P < 0.05) throughout the experimental period. These effects were not seen in the sham-SG and PF groups despite similar changes of weight loss or food intake.

CONCLUSIONS

The above results suggest that SG can conduct a direct control on T2DM instead of secondarily to weight loss or food intake around the whole experimental period. The changes of the gastrointestinal hormones may be the major mechanism of the antidiabetic effect.

Effects of laparoscopic sleeve gastrectomy in patients with morbid obesity and metabolic disorders

PURPOSES

Obesity and its correlation with other pathological conditions determine the onset of the metabolic syndrome, which exposes the patient to a higher risk of major cardiovascular complications. Laparoscopic sleeve gastrectomy (LSG) is a bariatric surgical procedure that appears to influence both the reduction of fat mass and the action of some gastrointestinal hormones.

PATIENTS AND METHODS

Between January 2011 and July 2013, 23 patients with morbid obesity underwent LSG and follow-up. In the evaluation of patients, the criteria for metabolic syndrome given by the International Diabetes Federation were followed. A multidisciplinary team of experts evaluated patients before surgery and in subsequent scheduled postoperative visits at 7, 30, 60, and 90 days and 4, 5, 6, 9, and 12 months. Anthropometric and metabolic parameters were analyzed.

RESULTS

The mean excess weight loss was 8.57±3.02%, 17.65±6.40%, 25.47±7.90%, 33.76±9.27%, 41.83±10.71%, 46.02±13.90%, 52.60±14.05%, 58.48±16.07%, and 62.59±21.29% at 7, 30, 60, and 90 days and 4, 5, 6, 9, and 12 months, respectively. In the same observational period there was an excellent improvement of metabolic indices. None of the patients previously taking prescribed hypoglycemic drugs restarted therapy. Mean fasting plasma glucose significantly decreased compared with the preoperative values. Blood pressure had a statistically significant improvement. Modification in the lipid profile was more variable. During the period of observation 22 of 23 patients reported in this study did not fit the criteria for metabolic syndrome.

CONCLUSIONS

Morbid obesity and related diseases may benefit from a surgical approach in selected patients. Randomized controlled trials are needed to evaluate the role of LSG.

Sub-sleeve gastrectomy achieves good diabetes control without weight loss in a non-obese diabetic rat model

BACKGROUND

Although weight loss has been implicated in anti-diabetic effects, sleeve gastrectomy (SG)-mediated anti-diabetic effects are induced through mechanisms beyond weight loss. Our aim was to investigate whether anti-diabetic effects can be achieved by surgically removing a smaller portion of the stomach instead of SG.

METHODS

Male 11-week-old Goto-Kakizaki rats (N = 50) were randomized into five groups: sub-sleeve gastrectomy (SSG, only the gastric fundus is removed), SG, sham-operated SSG, sham-operated SG, and control. Body weight, food intake, hormone secretion, and glucose metabolism were measured up to 24 weeks after surgery.

RESULTS

The data showed that (i) both SSG and SG surgeries significantly improved glucose homeostasis, with lower ghrelin levels and higher post-prandial glucagon-like peptide 1, peptide YY, and insulin levels; (ii) SG, but not SSG, produced sustained weight loss and significant reduction of food intake; and (iii) SG induced better long-term diabetic improvement than SSG.

CONCLUSIONS

The SSG that only removed the gastric fundus exhibited significant diabetic improvement without weight loss, but did not induce long-term diabetic improvement comparable to that of SG. Our study helps to understand the role of hormones and weight loss in maintaining long-term diabetes improvement after SG.

Type 2 diabetes control in a nonobese rat model using sleeve gastrectomy with duodenal-jejunal bypass (SGDJB)

BACKGROUND

As a new bariatric procedure, sleeve gastrectomy with duodenal-jejunal bypass (SGDJB) needs further assessment. We compared the diabetic control between SGDJB and sleeve gastrectomy (SG) in Goto-Kakizaki (GK) rats, a nonobese rat model of type 2 diabetes. Our aim is firstly to develop a nonobese diabetic rat model for SGDJB and secondly to investigate the feasibility and safety of SGDJB to induce diabetes remission.

METHODS

Fifty 11-week-old male GK rats were divided into five groups: sham-operated SG (SOSG), sham-operated SGDJB (SOSGDJB), control, SG, and SGDJB. Rats were observed for 16 weeks after surgery. The body weight, food intake, glycemic control outcomes, ghrelin, peptide YY (PYY), insulin, glucagon-like peptide 1 (GLP-1), and glucose-dependent insulinotropic peptide were measured.

RESULTS

The operated groups showed lower food intake since 4 weeks postoperation and significant weight loss since 6 weeks postoperation. SGDJB and SG surgeries induced a decreased fasting ghrelin level and increased levels of glucose-stimulated insulin, GLP-1, and PYY secretion at 2 and 16 weeks postoperation. Compared with the SG group, the SGDJB group showed higher glucose-stimulated GLP-1 levels. Both SGDJB and SG groups exhibited significant improvement in oral glucose tolerance and insulin tolerance compared with sham-operated and control groups, but there was no difference between the operated groups.

CONCLUSIONS

This nonobese diabetic rat model may be valuable in studying the effect of SGDJB on diabetic control. SGDJB shows similar improvement of glucose metabolism with SG. Our findings do not provide evidence for the foregut-mediated amelioration in glucose homeostasis.

Isolated duodenal exclusion increases energy expenditure and improves glucose homeostasis in diet-induced obese rats

Roux-en-Y gastric bypass (RYGB) in rodent models reduces food intake (FI), increases resting energy expenditure (EE), and improves glycemic control. We have shown that mimicking the duodenal component of RYGB by implantation of a 10-cm endoluminal sleeve device (ELS-10) induces weight loss and improves glycemic control in diet-induced obese (DIO) rats. We sought to determine the mechanisms and structural requirements of these effects. We examined the effects of ELS-10 devices implanted in male DIO rats on body weight, food intake (FI), meal patterns, total and resting EE, and multiple parameters of glucose homeostasis, comparing them with sham-operated (SO) rats and with SO rats weight matched to the ELS-10-treated group. To determine the extent of duodenal exclusion required to influence metabolic outcomes, we compared the effects of implanting 10-, 4-, or 1-cm ELS devices. ELS-10 rats exhibited 13% higher total and 9% higher resting EE than SO controls. ELS-10 rats also exhibited enhanced postprandial GLP-1 secretion and improved glucose tolerance and insulin sensitivity out of proportion to the effects of weight loss alone. Implantation of 4- or 1-cm ELS devices had no effect on EE and limited effects on glucose homeostasis. Complete duodenal exclusion with ELS-10 induces weight loss by decreasing FI and increasing EE and improves glycemic control through weight loss-independent mechanisms. Thus signals originating in the proximal small intestine appear to exert a direct influence on the physiological regulation of EE and glucose homeostasis. Their selective manipulation could provide effective new therapies for obesity and diabetes that mimic the benefits of RYGB.

Midterm Impact of Sleeve Gastrectomy, Calibrated with a 50-Fr Bougie, on Weight Loss, Glucose Homeostasis, Lipid Profiles, and Comorbidities in Morbidly Obese Patients

Bariatric surgery has been shown to be effective in achieving and maintaining weight change and reducing obesity-related comorbidities. Recent reports have shown that sleeve gastrectomy could have similar resolution rates of the metabolic syndrome than Roux-Y bypass after a short-term follow-up of 1 year. Most surgeons calibrate the sleeve with 32-Fr to 40-Fr bougies. There is little mid- and long-term information available about the evolution of these comorbidities with this procedure and with calibration of the sleeve with a 50-Fr bougie. A retrospective study of all the morbidly obese patients undergoing laparoscopic sleeve gastrectomy, calibrated with a 50-Fr bougie, as bariatric procedure between October 2007 and September 2009 was performed. Mean excessive body mass index loss was 76.9 per cent after 1 year and 79.9 per cent after 2 years. After surgery, 83.3 per cent of patients with Type 2 diabetes mellitus discontinued their hypoglycemic medication at 1 month. All the patients with hypertension discontinued antihypertensive drugs at 6 months. One hundred per cent of patients with hypertriglyceridemia discontinued their hypolipidemic drugs at 3 months. Glucose levels decreased significantly 3 months after surgery (mean reduction of 24.7 mg/dL; 95% confidence interval [CI], 8.8 to 40.7; P = 0.003). Triglyceride levels decreased 3 months after surgery (mean reduction of 54.4 mg/dL; 95% CI, 22.8 to 86.1; P = 0.004). High-density lipoprotein (HDL) cholesterol increased significantly after 12 months (increase of 16.7 mg/dL; 95% CI, 11.7 to 21.7; P < 0.001). The changes observed were maintained 24 months after surgery. Sleeve gastrectomy, calibrated with a 50-Fr bougie, significantly reduced glucose and triglyceride levels and the cardiovascular risk predictor triglyceride/HDL ratio and increased HDL levels after surgery and maintained them under normal ranges for at least 2 years.

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.

Honey--a novel antidiabetic agent

Diabetes mellitus remains a burden worldwide in spite of the availability of numerous antidiabetic drugs. Honey is a natural substance produced by bees from nectar. Several evidence-based health benefits have been ascribed to honey in the recent years. In this review article, we highlight findings which demonstrate the beneficial or potential effects of honey in the gastrointestinal tract (GIT), on the gut microbiota, in the liver, in the pancreas and how these effects could improve glycemic control and metabolic derangements. In healthy subjects or patients with impaired glucose tolerance or diabetes mellitus, various studies revealed that honey reduced blood glucose or was more tolerable than most common sugars or sweeteners. Pre-clinical studies provided more convincing evidence in support of honey as a potential antidiabetic agent than clinical studies did. The not-too-impressive clinical data could mainly be attributed to poor study designs or due to the fact that the clinical studies were preliminary. Based on the key constituents of honey, the possible mechanisms of action of antidiabetic effect of honey are proposed. The paper also highlights the potential impacts and future perspectives on the use of honey as an antidiabetic agent. It makes recommendations for further clinical studies on the potential antidiabetic effect of honey. This review provides insight on the potential use of honey, especially as a complementary agent, in the management of diabetes mellitus. Hence, it is very important to have well-designed, randomized controlled clinical trials that investigate the reproducibility (or otherwise) of these experimental data in diabetic human subjects.

Sleeve gastrectomy induces weight loss in diet-induced obese rats even if high-fat feeding is continued

BACKGROUND

Sleeve gastrectomy (SG) has been used for the surgical treatment of morbid obesity as a first or definitive procedure with satisfactory results. The objective of this study in rats was to establish the effects of SG on weight loss depending on the post-surgical type of diet followed.

METHODS

Thirty male Wistar rats were fed ad libitum during 3 months on a high-fat diet (HFD) to induce obesity. After this first phase, rats were subdivided in three groups of ten rats each and underwent a sham intervention, an SG, or no surgery but were pair-fed to the amount of food eaten by the animals of the SG group. At this time point, half of the animals in each group continued to be fed on the HFD, while the other half was switched to a normal chow diet (ND). Thus, the following subgroups were established: sham-ND, sleeve-ND, pair-fed-ND as well as sham-HFD, sleeve-HFD, and pair-fed-HFD. Body weight and food intake were recorded daily for 4 weeks. The feed efficiency rate (FER) was determined from weekly weight gains and caloric consumption during this period.

RESULTS

Statistically significant (P < 0.05) differences in body weight were observed between the six experimental groups after 4 weeks of the interventions with rats in the sleeve-ND group experimenting the highest weight loss (-78.2 ± 10.3 g) and animals in the pair-fed-HFD group exhibiting the lowest weight reduction (-4.0 ± 0.1 g). Interestingly, the FER value of rats that underwent the SG and continued to be fed on a HFD was significantly (P < 0.05) lower than that of sham operated and pair-fed animals on the same diet.

CONCLUSION

The positive effects of SG on weight reduction are observed in obese rats submitted to the intervention and subsequently following an ND or even an HFD.

The effect of vertical sleeve gastrectomy on food choice in rats

Objective

Diets high in fat are implicated in the development and maintenance of obesity, and obese individuals display greater preferences for high-fat foods than do their lean counterparts. Weight-reduction bariatric surgery is associated with changes in food choice. In particular, after Roux-en-Y Gastric Bypass (RYGB), humans and rodents select or prefer foods which are lower in fat content. We asked whether a bariatric surgical procedure limited to the stomach, Vertical Sleeve Gastrectomy (VSG), causes a similar reduction of fat intake/preference.

Research Design and Methods

Rats received VSG or Sham surgery or remained surgically naïve, and were assessed for food preference using three diet-choice paradigms. Using progressive-ratio and conditioned taste aversion paradigms, we further asked whether surgically-induced changes in food choice are secondary to changes in the reward value of food and/or to the formation of a food aversion. Finally, food choice was compared between VSG and RYGB-operated rats.

Results

VSG rats decreased their intake of dietary fat, and shifted their preference toward lower caloric-density foods. This change in food choice was not associated with changes in motivated responding on a progressive-ratio schedule for either a fat or a carbohydrate food reinforcer. When VSG and RYGB were compared directly, both procedures caused comparable changes in food choice. The conditioned taste aversion paradigm revealed that VSG rats form an aversion to an intra-gastric oil administration whereas RYGB rats do not.

Conclusions

VSG and RYGB, two anatomically-distinct bariatric procedures, produce similar changes in food choice.

Challenges and pitfalls of experimental bariatric procedures in rats

INTRODUCTION

The impact of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on obesity and obesity-related diseases is unquestionable. Up to now, the technical descriptions of these techniques in animals/rats have not been very comprehensive.

METHODS

For SG and RYGB, operating time, learning curve, and intraoperative mortality in relation to weight of the rat and type of anesthesia were recorded. Furthermore, a review of the literature on experimental approaches towards SG and RYGB in rats was carried out, merging in a detailed technical description for both procedures.

RESULTS

The data presented here revealed that the mean operating time for SG (69.4 ± 22.2 min (SD)) was shorter than for RYGB (123.0 ± 20.7 min). There is a learning curve for both procedures, resulting in a reduced operating time of up to 60% in SG and 35% in RYGB (p < 0.05; t-test). However, with increased weight, operating time increases to about 80 min for SG and about 120 min for RYGB. Obese rats have an increased intraoperative mortality rate of up to 50%. After gaseous anesthesia the mortality can be even higher. The literature search revealed 40 papers dealing with SG and RYGB in rats. 18 articles (45%) contained neither photographs nor illustrations; 14 articles (35%) did not mention the applied type of anesthesia. The mortality rate was described in 15 papers (37.5%).

CONCLUSION

Experimental obesity surgery in rats is challenging. Because of the high mortality in obese rats operated under gaseous anesthesia, exercises to establish the techniques should be performed in small rats using intraperitoneal anesthesia.

Impact of laparoscopic sleeve gastrectomy and laparoscopic gastric bypass on HbA1c blood level and pharmacological treatment of type 2 diabetes mellitus in severe or morbidly obese patients. Results of a multicenter prospective study at 1 year

Gastric bypass (GBP) has proved its efficacy 30 years ago in the management of diabetes mellitus (T2DM) for severe obese patients. More recently, interesting results have been published after sleeve gastrectomy (SG) in the same indication. Between 2005 and 2008, three bariatric centers have prospectively collected the data of T2DM patients treated by laparoscopic gastric bypass (LGBP) or laparoscopic sleeve gastrectomy (LSG). Effects on hemoglobin A1c (HbA1c), pharmacological treatment and excess weight loss after 1 year of surgery have been analyzed. All patients (35 LGBP and 33 LSG) were treated with oral anti-diabetics (OAD) or insulin before surgery (32 OAD and three insulin in LGBP group and 27 OAD and six insulin in LSG group). The average body mass index (BMI) in the LGBP group was 47.9 and 50.6 kg/m² in the LSG group. At 1 year after surgery, the average HbA1c lost was 2,537 in the GBP group and 2,175 in the SG group. T2DM had resolved (withdrawal of pharmacological treatment) in 60% of the LGBP group and 75.8% of the LSG group. Reduced use of pharmacological therapy was noted in 31.42% of the LGBP group and 15.15% of the LSG group. Percentage excess weight loss and BMI lost were 56.35% and 29.75% in the LGBP group and 60.11% and 29.80% in the LSG group, respectively. During short-term follow-up, the impact on regulation of HbA1c blood level of LGBP or LSG is important. At 1 year after surgery, LSG seems to be as effective as LGBP for the management of T2DM in severely obese patients.

Sleeve gastrectomy in rats improves postprandial lipid clearance by reducing intestinal triglyceride secretion

BACKGROUND & AIMS

Postprandial hyperlipidemia is a risk factor for atherosclerotic heart disease and is associated with the consumption of high-fat diets and obesity. Bariatric surgeries result in superior and more durable weight loss than dieting. These surgeries are also associated with multiple metabolic improvements, including reduced plasma lipid levels. We investigated whether the beneficial effects of vertical sleeve gastrectomy (VSG) on plasma lipid levels are weight independent.

METHODS

VSG was performed on Long-Evans rats with diet-induced obesity. Controls were sham-operated animals who were either pair-fed or ad libitum-fed. We measured fasting and postprandial levels of plasma lipid. To determine hepatic and intestinal triglyceride secretion, we injected the lipase inhibitor poloxamer 407 alone or before oral lipid gavage. (13)C-Triolein was used to estimate postprandial uptake of lipid in the intestine.

RESULTS

Rats that received VSG and high-fat diets had markedly lower fasting levels of plasma triglyceride, cholesterol, and phospholipid than obese and lean (pair-fed) controls that were fed high-fat diets. Rats that received VSG had a marked, weight-independent reduction in secretion of intestinal triglycerides. VSG did not alter total intestinal triglyceride levels or size of the cholesterol storage pool nor did it affect the expression of genes in the intestine that control triglyceride metabolism and synthesis. VSG did not affect fasting secretion of triglyceride, liver weight, hepatic lipid storage, or transcription of genes that regulate hepatic lipid processing.

CONCLUSIONS

VSG reduced postprandial levels of plasma lipid, independently of body weight. This resulted from reduced intestinal secretion of triglycerides following ingestion of a lipid meal and indicates that VSG has important effects on metabolism.

Laparoscopic sleeve gastrectomy with duodenojejunal bypass for the treatment of type 2 diabetes in non-obese patients: technique and preliminary results

BACKGROUND

Medical treatment of type 2 diabetes has often insufficient clinical results at long term. Although the surgical option is a well-established alternative for obese patients, the procedures in non-obese are currently being developed.

METHODS

A 12-month prospective trial with ten diabetic non-obese patients who underwent laparoscopic sleeve gastrectomy with duodenojejunal bypass is presented. Changes in fasting blood glucose, HbA1c, weight, and BMI were determined.

RESULTS

There was a significant reduction in fasting glycemia and HbA1c at 1 year postoperative (p < 0.004). One patient had an intra-abdominal bleeding and a wound infection treated with blood transfusion and antibiotic therapy, respectively. The BMI decreased 12.1% and in any case it was reduced to less than 20 kg/m².

CONCLUSIONS

Laparoscopic sleeve gastrectomy with duodenojejunal bypass is a promising procedure for the treatment of non-obese patients with type 2 diabetes. Studies with large number of patients and longer follow-up are necessary to make definitive conclusions.

Bypassing the duodenum does not improve insulin resistance associated with diet-induced obesity in rodents

Roux-en-y gastric bypass (RYGB) surgery rapidly improves glucose tolerance and reverses insulin resistance in obese patients. It has been hypothesized that this effect is mediated by the diversion of nutrients from the proximal small intestine. We utilized duodenal-jejunal bypass (DJB) as a modification of gastric bypass to determine the effect of nutrient diversion from the foregut without gastric restriction on insulin resistance in obese rats. The effects of DJB or Sham surgery on glucose homeostasis were determined in both high-fat-fed Long-Evans and Wistar rats. Body weight and food intake were measured weekly postoperatively, and body composition was monitored before and after surgery. Glucose tolerance was tested before and as early as 1 month postoperation; additionally, in Wistar rats, insulin sensitivity was determined by a hyperinsulinemic-euglycemic clamp (HIEC). DJB did not affect body weight, body composition, glucose tolerance, or insulin concentrations over the period of the study. The average glucose infusion rate (GIR) during the HIEC was 6.2 ± 1.16 mg/kg/min for Sham rats compared to 7.2 ± 1.71 mg/kg/min for DJB rats (P = 0.62), and neither endogenous glucose production (EGP; P = 0.81) nor glucose utilization (glucose disappearance (R(d)), P = 0.59) differed between DJB and Sham rats. DJB does not affect insulin resistance induced by a high-fat diet in Long-Evans and Wistar rats. These data suggest that duodenal bypass alone is an insufficient mechanism to alter insulin sensitivity independent of weight loss in obese, nondiabetic rodents.

Effects of sleeve gastrectomy in neonatally streptozotocin-induced diabetic rats

Background

Sleeve gastrectomy (SG) has emerged recently as a stand-alone bariatric procedure to treat morbid obesity and enhance glucose homeostasis. The aim of the study was to evaluate its effects in neonatally streptozotocin (STZ)-induced diabetic rats (n-STZ diabetic rats).

Methodology and Principal Findings

To induce diabetes, STZ (90 mg/kg) was administered intraperitoneally to 2-day-old male pups. When 12 weeks old, diabetic rats were randomized into sleeve operation group (SLG, n = 6) and sham operation group (SOG, n = 6). Body weights were monitored weekly, and daily consumption of water and food were followed for eight consecutive weeks postoperatively. Serum glucose levels were measured periodically at the 4th and 8th week after surgery. Insulin, ghrelin, glucose-dependent insulinotropic polypeptide (GIP) and Glucagon-like peptide-1 (GLP-1) levels were assayed at the end of the study. Our data showed that SLG rats exhibited significantly lower body weight gain in addition to reduced food and water intakes postoperatively compared to their sham-operation counterparts. However, resolution of diabetes was not observed in our study. Correspondingly, there were no significant differences between SOG rats and SLG rats in glucose metabolism-associated hormones, including insulin, GIP and GLP-1. In contrast, ghrelin level significantly decreased (P<0.01) in SLG group (58.01±3.75 pg/ml) after SG surgery compared to SOG group (76.36±3.51 pg/ml).

Conclusions

These observations strongly suggest that SG is effective in controlling body weight. However, SG did not achieve resolution or improvement of diabetes in n-STZ diabetic rats.

Sleeve gastrectomy and type 2 diabetes mellitus: a systematic review

BACKGROUND

Existing evidence has suggested that bariatric surgery produces sustainable weight loss and remission or cure of type 2 diabetes mellitus (DM). Laparoscopic sleeve gastrectomy (LSG) has garnered considerable interest as a low morbidity bariatric surgical procedure that leads to effective weight loss and control of co-morbid disease. The objective of the present study was to systematically review the effect of LSG on type 2 DM.

METHODS

An electronic data search of MEDLINE, PubMed, Embase, Scopus, Dare, Clinical Evidence, TRIP, Health Technology Database, Conference abstracts, clinical trials, and the Cochrane Library database was completed. The search terms used included LSG, vertical gastrectomy, bariatric surgery, metabolic surgery, and diabetes (DM), type 2 DM, or co-morbidities. All human studies, not limited to those in the English language, that had been reported from 2000 to April 2010 were included.

RESULTS

After an initial screen of 3621 titles, 289 abstracts were reviewed, and 28 studies met the inclusion criteria and the full report was assessed. One study was excluded after a careful assessment because the investigators had combined LSG with ileal interposition. A total of 27 studies and 673 patients were analyzed. The baseline mean body mass index for the 673 patients was 47.4 kg/m(2) (range 31.0-53.5). The mean percentage of excess weight loss was 47.3% (range 6.3-74.6%), with a mean follow-up of 13.1 months (range 3-36). DM had resolved in 66.2% of the patients, improved in 26.9%, and remained stable in 13.1%. The mean decrease in blood glucose and hemoglobin A1c after sleeve gastrectomy was -88.2 mg/dL and -1.7%, respectively.

CONCLUSION

Most patients with type 2 DM experienced resolution or improvement in DM markers after LSG. LSG might play an important role as a metabolic therapy for patients with type 2 DM.

Ghrelin, des-acyl ghrelin and nesfatin-1 in gastric X/A-like cells: role as regulators of food intake and body weight

Numerous peptides released from endocrine cells in the intestinal mucosa were established early on to be involved in the physiological regulation of food intake with a prominent role in termination of food ingestion when nutrients pass along the intestinal tract. Recently, peptides released from X/A-like endocrine cells of the gastric oxyntic mucosa were recognized as additional key players in the regulation of feeding and energy expenditure. Gastric X/A-like cells release the octanoylated peptide, ghrelin, the only known peripherally produced hormone stimulating food intake through interaction with growth hormone secretagogue 1a receptor (GHS-R1a). Additionally, non-octanoylated (des-acyl) ghrelin present in the circulation at higher levels than ghrelin is currently discussed as potential modulator of food intake by opposing ghrelin's action independent from GHS-R1a although the functional significance remains to be established. Obestatin, a ghrelin-associated peptide was initially reported as anorexigenic modulator of ghrelin's orexigenic action. However, subsequent reports did not support this contention. Interesting is the recent identification of nesfatin-1, a peptide derived from the nucleobindin2 gene prominently expressed in gastric X/A-like cells in different vesicles than ghrelin. Circulating nesfatin-1 levels vary with metabolic state and peripheral or central injection inhibits dark phase feeding in rodents. Overall, these data point to an important role of gastric X/A-like cells in food intake regulation through the expression of the orexigenic peptide ghrelin along with des-acyl ghrelin and nesfatin-1 capable of reducing food intake upon exogenous injection although their mechanisms of action and functional significance remain to be established.