Evidence for a metabolic mechanism in the improvement of type 2 diabetes after sleeve gastrectomy in a rodent model.

BACKGROUND: Sleeve gastrectomy (SG) is at least as effective at producing weight loss as gastric banding but may be superior in producing remission of type 2 diabetes mellitus (T2DM). The objective of this study was to elucidate mechanisms of diabetes improvement in SG beyond caloric restriction. We studied SG in Zucker Diabetic Fatty (ZDF) rats. METHODS: Twenty-eight ZDF rats were randomly assigned to 1 of 3 groups: SG, sham-operated ad lib fed (AL), or sham-operated pair fed (PF). SG and AL rats had free access to food. PF rats were fed the average daily intake of the SG group. Comparisons of caloric intake, weight loss, intraperitoneal glucose tolerance testing (IPGTT), insulin, and total ghrelin were performed preoperatively and at postoperative days 10, 20, and 30. Differences between means were evaluated using one-way ANOVA and the paired t test as appropriate. RESULTS: Postoperatively, SG rats had lower daily caloric intake than the AL controls (78.3±10.5 kcal versus 104.7±4.6 kcal). Both SG and PF groups had sustained weight loss (-5.3±3.8 g and -27.5±2.6 g, respectively); however, SG rats had significantly lower AUC for glucose after IPGTT than both controls. This is in contrast to AL controls that experienced weight gain (34.1±4.7 g) and increases in AUC for glucose after IPGTT. CONCLUSION: Although SG is considered a restrictive procedure, there is evidence for a metabolic effect by virtue of decreased insulin resistance, which may not be reproduced by PF controls.

Repletion of S-nitrosohemoglobin improves organ function and physiological status in swine after brain death.

OBJECTIVE: To determine if reduction in nitric oxide bioactivity contributes to the physiological instability that occurs after brain death and, if so, to also determine in this setting whether administration of a renitrosylating agent could improve systemic physiological status. BACKGROUND: Organ function after brain death is negatively impacted by reduced perfusion and increased inflammation; the magnitude of these responses can impact post-graft function. Perfusion and inflammation are normally regulated by protein S-nitrosylation but systemic assessments of nitric oxide bioactivity after brain death have not been performed. METHODS: Brain death was induced in instrumented swine by inflation of a balloon catheter placed under the cranium. The subjects were then serially assigned to receive either standard supportive care or care augmented by 20 ppm of the nitrosylating agent, ethyl nitrite, blended into the ventilation circuit. RESULTS: Circulating nitric oxide bioactivity (in the form of S-nitrosohemoglobin) was markedly diminished 10 hours after induction of brain death-a decline that was obviated by administration of ethyl nitrite. Maintenance of S-nitrosohemoglobin was associated with improvements in tissue blood flow and oxygenation, reductions in markers of immune activation and cellular injury, and preservation of organ function. CONCLUSIONS: In humans, the parameters monitored in this study are predictive of post-graft function. As such, maintenance of endocrine nitric oxide bioactivity after brain death may provide a novel means to improve the quality of organs available for donation.

Obesity and bariatric surgery.

Laparoscopic Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding are the most commonly performed weight reduction operations in the United States. Preoperative assessment and selection should be performed by a multidisciplinary team to obtain optimal results. The most devastating complication of bariatric surgery is leak, which can carry a high risk of mortality if not detected and treated expediently. New nationwide databases have been developed to monitor outcomes and facilitate better understanding of the mechanisms of bariatric surgery. New horizons for the advancement of bariatric surgery are in the realm of surgery in adolescent and geriatric populations, the use of weight-loss surgery in lower body mass index (<35 kg/m(2)) populations, and the use of surgery to cure the comorbidities of obesity.