Πειραματική μελέτη της χειρουργικής θεραπείας του σακχαρώδη διαβήτη τύπου 2 μετά από πλαγιο-πλάγια νηστιδοειλεϊκή αναστόμωση σε σακχαροδιαβητικά ποντίκια
Αρουραίοι ράτσας Goto-Kakazaki
Διαβήτης τύπου 2
Diabetes type 2
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AbstractSummaryIt is well known that Diabetes Mellitus type 2 (DMT2) is a world epidemic in recent years. Although there is enormous effort by the Medical community to treat the disease conservatively, this is not always possible due to the modern way of life, which involve bad dietary habits, luck of physical activity and weight gain. The latest is of the outmost importance and according to studies, 80% of the morbid obese people would finally develop DMT2.According to WHO the number of obese European citizens is approximately 150.000.000 people and the number of obesity related deaths is 1.000.000 annually.From 1954 a variety of surgical techniques have been utilized for treatment of morbid obesity with minimal morbidity and mortality. To date the approved operations for the management of severe obesity are:a)Adjustable gastric bandingb)Sleeve gastrectomyc)R-en-Y Gastric bypassd)Biliopancreatic DiversionIt is remarkable that following bariatric surgery the remission of co-existing diseases such as DMT2 may be as high as 80-90%. Similar results are obtained with other obesity co-morbidities as arterial hypertension, dyslipidemia and sleep apnea syndrome.Over 200.000.000 people worldwide are suffering today from DMT2. In Greece the incidence of the disease is estimate from 5.9% to 7% of the population. According to epidemiological estimations at the year 2025 the number of people with DMT2 would be 600.00.000 and this is going to represent the 7.3% of the world’s population. In the Diabetes Surgery Summit in Rome 2007 the decision was made that when DMT2 is not controlled by life style changes and medications, surgery would be considered in patients with BMI ≥30kg/m2. Bariatric Surgery for Diabetes Type 2Encouraging results following surgical treatment of patients with DMT2 have been reported by many investigators.The first procedure used for the treatment of morbid obesity and Diabetes Mellitus type 2 was the Roux-en Y gastric bypass, followed by the vertically banded gastroplasty. The results of the latest ware not as good as hen the gastric bypass was utilized.Other bariatric operations that were also used for treatment of patients with DMT2 were the adjustable gastric banding. The sleeve gastrectomy and the biliopancreatic diversion.Specific for DMT2 treatment in obese or overweighed patients were the duodenojejunal sleeve, the duodeno-jejunal bypass, the ileal interposition and the sleeve gastrectomy with bipartition with gastrojejunostomy or Roux-en-Y jejunostomy.In recent years in an effort to discover simple new procedures for surgical management of the diabetic patients and provide explanations for the mechanism of diabetes remission research have been made into the role of enteropeptides in the regulation of glucose homeostasis, as well as in weight loss.Neuroendocrine regulationThe role of central nervous system in body’s homeostasis through hormonal feedback mechanisms is crucial. Hormones like GLP-1, PYY, Insulin, Ghrelin, Resistin and Leptin are responding to chemical and mechanical stimulation of the gut and are important parameters in regulation of body weight and glucose homeostasis.Aim of the studyFor enhancing weight-loss in morbidly obese patients, the addition of a side-to-side jejunoileal anastomosis to sleeve gastrectomy has previously been described from our group. The very successful results in diabetic remission, observed following this procedure in morbidly obese diabetic patients, lead us to the assumption that diverting and accelerating the food transmission into the distal small bowel with a simple jejunoileal anastomosis, in non-obese diabetic patients were weight-loss is not the main goal, will act therapeutically by stimulating the L cells of the ileum for incretins production. Therefore, SJA was performed in GK rats in order to determine whether this food diverting procedure is able to induce diabetes control in a non-obese animal model, and establish a suitable experimental setting for further studies of the mechanism/s for diabetes control.Experimental animals and methodsNine to 10 week-old male diabetic, normolipidemic Goto-Kakizaki (GK) rats were purchased from ‘Charles River’ Research Models and Services (Boston USA). All animals were housed in individual cages under standard conditions (constant ambient temperature of 22°C and humidity of 60% in a 12-hour light/dark cycle) in the animal house, Heraklion University Hospital with free access to water. Animals were fed with a 2% fat and 16.5 % protein rat chow diet (kounker, Athens, Greece) before operation. The animal experiment in this study were approved by the Ethics committee of the Medical School, University of Crete, and received permission from Heraklion Regional Veterinary Service. All applicable institutional and/or national guidelines for the care and use of animals were followed. Rats were allowed 4 weeks for acclimation before the experiment. After that, 17 rats randomly underwent one of the following procedures: SJA: 11 animals, sham side-to-side jejunoileal anastomosis (SSJA): 4 animals or no intervention (controls): 2 animals. Weight, fasting glucose, cholesterol, triglycerides and oral glucose tolerance test (OGTT) were measured at intervals according to the experimental schedule. The operative times (time from the beginning of the midline abdominal incision to the end of suturing of the abdominal incision) of SJA and SSJA groups were accurately recorded. Moreover, the time of first postoperative defecation (an indicator of postoperative recovery time) and all postoperative complications were extensively recorded.Surgical techniqueBefore operations, rats were fasted overnight for 12 hours. Rats were anesthetized with ketamine hydrochloride 50mg/ml (Molteni Farmaceutical, Firenze, Italy) during the surgery. SJA procedure (Fig.1) involved (1) a 4-cm midline abdominal incision, (2) measurement of the length of the entire small intestine from the Treitz ligament to the ileocecal valve, (3) estimation of the length of small bowel equal to 20% of its entire length, (4) identification of a point distal to the Treitz ligament at a distance equal with 20% of the total bowel length, (5) identification of a point proximal to the Ileocecal valve at a distance equal with 20% of the total bowel length, (6) side-to-side anastomosis between jejunum and ileum at the measured points distal to the Treitz and proximal to the ileocecal valve using 6-0 polydioxanone monofilament absorbable sutures (PDS Johnson and Johnson, USA), (7) closure of the abdominal incision using 4-0 polyglycolic acid absorbable sutures (Safil Braun, Tuttlingen Germany), (8) closure of the skin incision with subcuticular suture with the same suturing material.Sham operations were performed by the same abdominal incisions and same jejunoileal anastomosis. Thereafter, the anastomosis was taken down with restoration of the small bowel continuity using 6-0 PDS sutures. Rats had free access to water 2 hours after surgery as well as free access to food 24 hours postoperatively. Food intake was not limited. Both groups were fed the same perioperative diet. Weight was measured every 7 days until the 10th week when the study was terminated.Biochemical methodsBlood glucose, cholesterol and triglycerides were measured using a quantitative instrument (Accutrend Plus, Roche Diagnostic, Mannheim, Germany). Before operation and every week postoperatively, from the first until the 10th when the experiment was terminated, blood samples were collected after 12 hours overnight fast from tail’s vein of conscious rats, for measuring of serum glucose levels. Cholesterol and triglyceride levels were measured before operation and at the 3rd and the 8th postoperative weeks. OGTT was performed preoperatively and at 3 and 8 weeks after surgery. After an overnight fast, rats were administrated with 1 g/kg glucose by oral gavage and blood glucose levels were measured before, 30, 60 and 120 minutes after the oral gavage. Statistical analysis All statistical analyses were performed with SPSS 17.0. Data was expressed asMedian and range. All p values are two-tailed. Because of the small animal numbers in the 3 groups, data were compared using non-parametric tests for different population. Mann-Whitney U-tests were used for comparisons between groups and Wilcoxon paired test for intra-group comparisons. p<0.05 was considered statistically significant. ResultsAll operations were successful. However, compared with SJA, the operation time 47.5 min (range 25-60 min) vs 89.5 min (range 45-105 min) of SSJA was longer (p < 0.01). There was no significant (NS) differences in postoperative recovery time for SJA, 2 days (range 1-3 days) vs SSJA, 2 days (range 1-2 days) (p =0,9). One SJA rat died from intestinal obstruction, due to torsion of the anastomosis along the longitudinal axis, at day 32 after the operation. No deaths neither complications were observed in the sham-operated and control groups. Length of small intestineAt 14 week the measured average intestinal length of SJA animals from Treitz ligament to the ileocecal valve was 89 cm (range 70-118 cm) and for SSJA animals 84 cm (range 65-95 cm), (p=0.57 NS).Weight and postoperative weight lossAt week 0, the median weight for the 3 groups were: SJA 358 g (range 354-366 g), SSJA 355.5 g (range 345-360 g) and Controls 360 g (range 355-365 g). The p values for the differences between groups were SJA vs Sham SJA p=0.32, SJA vs Controls p=0.9 and SSJA vs Controls p=0.36, all NS. Animals in SJA group experienced loss of weight from the first and up to 4 weeks after the operation. The median % TWL observed at that time point was 7.2%. The weight of the rats in this group was stabilized thereafter, but remained reduced comparing with the pre-operative values (p<0.001) until the end of the experiment.Glucose metabolismGlucoseAnimals in Control group and those in SJA and SSJA groups have no statistically different fasting glucose levels before the procedures. SJA: median 213.5 mg/dl (range 181-260), Controls: median 308 mg/dl (range 280-336), Sham: median 235 mg/dl (range 219-248). SJA vs Sham p=0.4 NS, SJA vs Controls p=0.062 NS and Sham vs Controls p= 0.074 NSHowever, compared with sham-operated rats and controls, the fasting glucose levels were significantly lower in the SJA group (p<0.01) from the 1st postoperative week and continued to be within normal range up to the 10th week when the experiment was terminated.OGTTPrior to the procedures, no statistical difference in OGTT was found among all experimental groups. At 120 min following administration of 1 gr/kg glucose by oral gavage, the median plasma glucose levels were 301.5 mg/dl (range: 261-480 mg/dl) for SJA, 409 mg/dl (range: 327-439 mg/dl) for Sham group and 378 mg/dl (range: 300-457 mg/dl) for the Control group. SJA vs Sham p=0.076 NS, SJA vs Control p=0.052 NS and Sham vs Control p=1.00 NS. However, all rats in the side-to-side jejunoileal bypass group showed a significant improvement in glucose tolerance test at 120 min following administration of 1g/kg glucose by oral gavage at 3 and 8 weeks post operatively. [273.5 (57-382) mg/dl; p=0.02 and 95.5 (70-241) mg/dl; p=0.005, respectively]. On the contrary, no significant changes were observed either in Sham [414 (188-510) mg/dl; p=0.72 NS and 414 (188-510) mg/dl; p=0.07 NS, respectively], or in the Control [383 (346-420) mg/dl; p=0.66 NS and 457.5 (400-515) mg/dl; p=0.18 NS, respectively] groups. Cholesterol and triglycerides levelsSerum cholesterol and triglycerides levels had no difference prior to surgery among all experimental groups. No significant differences in those parameters were observed following SJA or Sham procedures.ConclusionsThis experimental investigation in non-obese diabetic rats, showed that with diversion of food and biliopancreatic juices to the distal ileum, with a simple side-to-side jejunoileal anastomosis, glucose homeostasis is restored.Many pathophysiological mechanisms may be contributing in diabetes remission observed in this non obese animal model. It is remarkable that none of the animals developed diarrhea or other signs of malabsorption postoperatively. Although even without sleeve gastrectomy, simple jejunoileal anastomosis resulted in minimal weight loss of around 7.2%. It is no doubt that this long term weight loss is resulting in improving insulin sensitivity, which is contributing in diabetes control. However, the weight loss cannot fully explaine the rapid remission of diabetes seen in the animals in this experiment.Is very likely that other mechanisms are responsible for diabetes control, following side-to-side jejunoileal anastomosis. Previous studies showed a positive effect in glucose homeostasis after operations resulting in fast passage of food into the distal small bowel, as the sleeve gastrectomy. The present study showed that rapid improvement of insulin sensitivity occur independent of weight loss. It is speculated that GLP-1 and PYY endero-peptides that the gut is secreting following rapid passage of food into the distal ileum are the most possible explanation for diabetes control, apart from the weight loss.