Torsten Olbers

Gastric Bypass Increases Energy Expenditure in Rats

BACKGROUND & AIMSnMechanisms underlying weight loss maintenance after gastric bypass are poorly understood. Our aim was to examine the effects of gastric bypass on energy expenditure in rats.nnnMETHODSnThirty diet-induced obese male Wistar rats underwent either gastric bypass (n = 14), sham-operation ad libitum fed (n = 8), or sham-operation body weight-matched (n = 8). Energy expenditure was measured in an open circuit calorimetry system.nnnRESULTSnTwenty-four-hour energy expenditure was increased after gastric bypass (4.50 +/- 0.04 kcal/kg/h) compared with sham-operated, ad libitum fed (4.29 +/- 0.08 kcal/kg/h) and sham-operated, body weight-matched controls (3.98 +/- 0.10 kcal/kg/h, P < .001). Gastric bypass rats showed higher energy expenditure during the light phase than sham-operated control groups (sham-operated, ad libitum fed: 3.63 +/- 0.04 kcal/kg/h vs sham-operated, body weight-matched: 3.42 +/- 0.05 kcal/kg/h vs bypass: 4.12 +/- 0.03 kcal/kg/h, P < .001). Diet-induced thermogenesis was elevated after gastric bypass compared with sham-operated, body weight-matched controls 3 hours after a test meal (0.41% +/- 1.9% vs 10.5% +/- 2.0%, respectively, P < .05). The small bowel of gastric bypass rats was 72.1% heavier because of hypertrophy compared with sham-operated, ad libitum fed rats (P < .0001).nnnCONCLUSIONSnGastric bypass in rats prevented the decrease in energy expenditure after weight loss. Diet-induced thermogenesis was higher after gastric bypass compared with body weight-matched controls. Raised energy expenditure may be a mechanism explaining the physiologic basis of weight loss after gastric bypass.

Effect of the definition of type II diabetes remission in the evaluation of bariatric surgery for metabolic disorders.

The American Diabetes Association recently defined remission of type II diabetes as a return to normal measures of glucose metabolism (haemoglobin (Hb) A1c below 6 per cent, fasting glucose less than 5·6 mmol/l) at least 1 year after bariatric surgery without hypoglycaemic medication. A previously used common definition was: being off diabetes medication with normal fasting blood glucose level or HbA1c below 6 per cent. This study evaluated the proportion of patients achieving complete remission of type II diabetes following bariatric surgery according to these definitions.

Vagal Sparing Surgical Technique but Not Stoma Size Affects Body Weight Loss in Rodent Model of Gastric Bypass

BackgroundThe aim of this study was to evaluate whether gastric bypass with or without vagal preservation resulted in a different outcome.MethodsBody weight, food intake and postprandial peptide YY (PYY) and glucagon-like peptide (GLP-1) levels were compared between gastric bypass (nu2009=u200955) and sham-operated rats (nu2009=u200927) in three groups. In group 1 (nu2009=u200917), the vagal nerve was not preserved, while in group 2 the vagal nerve was preserved during gastric bypass (nu2009=u200910). In group 3, gastric bypass rats (nu2009=u200928) were randomised for either one of the two techniques.ResultsRats in which the vagal nerve was preserved during gastric bypass showed a lower body weight (pu2009<u20090.001) and reduced food intake (pu2009<u20090.001) compared to rats in which the vagal nerve was not preserved during the gastric bypass operation. Levels of PYY and GLP-1 were significantly increased after gastric bypass compared to sham-operated controls (pu2009<u20090.05), but there was no difference between gastric bypass rats with and without vagal preservation. Differences in food intake and body weight were not related to the size of the gastro-jejunostomy in gastric bypass rats. There were no signs of malabsorption or inflammation after gastric bypass.ConclusionWe propose that the vagal nerve should be preserved during the gastric bypass operation as this might play an important role for the mechanisms that induce weight loss and reduce food intake in rats. In contrast, the gastro-jejunal stoma size was found to be of minor relevance.

Bariatric Surgery Does Not Exacerbate and May Be Beneficial for the Microvascular Complications of Type 2 Diabetes

The effects of bariatric surgery on microvascular complications remain underexplored despite more than 40 years of surgery on patients with type 2 diabetes. The literature has focused predominantly on glycemic control and very little on diabetes-related complications, which confer high rates of morbidity and mortality. Our aim was to assess whether the gastric bypass, sleeve gastrectomy, and gastric banding procedures are safe for the retinal and renal complications of type 2 diabetes, especially as they lead to rapid improvements in glycemia, which may paradoxically cause or exacerbate microvascular complications.nnProspectively collected retinal photographs (two-field) and urine albumin creatinine ratios (ACRs) were analyzed retrospectively in 84 consecutive patients with type 2 diabetes before and 12–18 months after surgery. The results were confirmed by an independent ophthalmologist who was blinded to clinical information. Improvement or deterioration was defined as a decrease or increase of at least two …

Fast-track laparoscopic bariatric surgery: a systematic review

This study aimed to systematically evaluate the evidence-based literature on fast-track laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic adjustable gastric banding (LAGB) to determine the feasibility and safety of fast-track laparoscopic bariatric surgery. A literature search of PubMed, EMBASE and Cochrane Library using the MeSH terms “bariatric surgery”, “ambulatory surgical procedures” and related terms as keywords was performed. The study included articles that reported on intended next-day discharge for LRYGB and same-day discharge for LAGB. Data were extracted on study design and size, patient demographics, patient-selection criteria, patient preparation, perioperative management, operative details, clinical outcomes, and follow-up. The review included 13 studies classified as level 3b or 4 evidence. There were seven studies that investigated LAGB, five studies investigated LRYGB and one study detailed outcomes from both LRYGB and LAGB. Next-day discharge rate ranged from 81 to 100xa0% for LRYGB. Same-day discharge rate ranged from 76 to 98xa0% for LAGB. In LRYGB and LAGB complication, re-admission and mortality rates (≤10.5, ≤7.5, ≤0.1xa0%, respectively) were comparable with the conventional perioperative care. From our results, the fast-track management of patients undergoing LRYGB and LAGB is feasible. With careful patient selection and preparation within high-volume centres, and application of care pathways including close outpatient follow-up, outcomes for fast-track bariatric procedures can compare favourably with those reported in the literature for standard management, but with decreased cost. However, further studies from independent researchers are required to determine the safety of a generalised adoption of this approach outside of dedicated bariatric units, and to formally demonstrate the cost-benefit of fast-track bariatric surgery.

Effect of bypassing the proximal gut on gut hormones involved with glycemic control and weight loss

BACKGROUNDnThe reported remission of type 2 diabetes in patients undergoing Roux-en-Y gastric bypass has brought the role of the gut in glucose metabolism into focus. Our objective was to explore the differential effects on glucose homeostasis after oral versus gastrostomy glucose loading in patients with Roux-en-Y gastric bypass at an academic health science center.nnnMETHODSnA comparative controlled investigation of oral versus gastrostomy glucose loading in 5 patients who had previously undergone gastric bypass and had a gastrostomy tube placed in the gastric remnant for feeding. A standard glucose load was administered either orally (day 1) or by the gastrostomy tube (day 2). The plasma levels of glucose, insulin, glucagon-like peptide 1 and peptide YY were measured before and after glucose loading.nnnRESULTSnExclusion of the proximal small bowel from glucose passage induced greater plasma insulin, glucagon-like peptide 1, and peptide YY responses compared with glucose loading by way of the gastrostomy tube (P <.05).nnnCONCLUSIONSnExclusion of glucose passage through the proximal small bowel results in enhanced insulin and gut hormone responses in patients after gastric bypass. The gut plays a central role in glucose metabolism and represents a target for future antidiabetes therapies.

Long‐term results of a randomized clinical trial comparing Roux‐en‐

The long‐term results of Roux‐en‐

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gastric bypass with vertical banded gastroplasty

gastric bypass (gastric bypass) and vertical banded gastroplasty (VBG) from randomized studies have not been described in detail.

Assessment of obesity beyond body mass index to determine benefit of treatment

•u2002 Weight or weight loss per se may not indicate health status or health benefit. •u2002 There is no gold standard for assessing which patients would benefit most from weight‐loss interventions. •u2002 The Kings Criteria is one of several recently proposed obesity classification systems.