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Print version ISSN 1807-5932
Clinics vol.64 no.11 São Paulo Nov. 2009
Glucose homeostasis and weight loss in morbidly obese patients undergoing banded sleeve gastrectomy: a prospective clinical study
Gustavo Peixoto Soares MiguelI; Joao Luiz Moreira Coutinho AzevedoII; Carlos Gicovate NetoI; Cora Lavigne Castelo Branco MoreiraI; Elaine Cristina VianaI; Perseu Seixas CarvalhoI
IFederal University of Espírito Santo - Vitória/ES, Brazil
IIFederal University of São Paulo - São Paulo/SP, Brazil. Email: firstname.lastname@example.org. Tel: 55 11 5571.0946
OBJECTIVE: To assess glucose homeostasis and weight loss in morbidly obese patients undergoing Silastic® ring sleeve gastrectomy.
METHODS: This was a prospective clinical study. Thirty-three female patients with a mean body mass index (BMI) of 42.33 ± 1.50 kg/m2 (range: 40-45 kg/m2), a mean age of 36.7 ± 9.4 years and a mean waist circumference of 118.7 ± 5.98 cm were included in this study. Type 2 diabetes mellitus was observed in 11 patients (33.3%), and glucose intolerance was observed in 4 patients (12.1%). Mean plasma fasting glucose levels were 109.77 ± 44.19 mg/dl (75-320) in the preoperative period. All Silastic® ring sleeve gastrectomy procedures were performed by the same surgical team using the same anesthetic technique. The patients were monitored for at least 12 months after surgery.
RESULTS: The mean weight of the patients decreased from 107.69 ± 6.57 kg to 70.52 ± 9.36 kg (p < 0.001), the mean BMI decreased to 27.4 ± 2.42 kg/m2 (p < 0.001), and the mean waist circumference decreased to 89.87 cm ± 6.66 (p < 0.001) in the postoperative period. Excess BMI loss was 86.5 ± 14.2%. Fasting glucose levels were reduced to 80.94 ± 6.3 mg/dl (p < 0.001). Remission of diabetes and glucose intolerance was observed in all patients.
CONCLUSION: Silastic® ring sleeve gastrectomy was effective in promoting weight loss, waist circumference reduction and control of glucose homeostasis in morbidly obese patients.
Keywords: Type 2 diabetes mellitus, Obesity, Bariatric Surgery, Weight loss.
Obesity is a multifactorial disease that affects millions of people worldwide. It is the main independent risk factor for developing type 2 diabetes mellitus (T2DM),1,2 leading to a condition known as diabesity.2,3 In patients with morbid obesity, the likelihood of developing T2DM and glucose intolerance (GI) is further increased.1,4
Bariatric surgery provides sustained weight loss and leads to well-documented remission of T2DM in obese, diabetic patients.5,6 Patients who undergo bariatric surgery have a decreased rate of long-term mortality compared to obese patients who do not receive bariatric surgery,7 with 136 lives saved per 10,000 surgical procedures performed.8 Currently, bariatric surgery is the most effective choice of treatment for morbidly obese patients with T2DM.9
Surgical procedures to treat morbid obesity are divided into two groups: gastric restrictive procedures and procedures that combine gastric restriction and malabsorption.10 The Roux-en-Y gastric bypass (RYGB) procedure is well-established and is the most frequent bariatric surgery performed,7,11 whereas sleeve gastrectomy (SG) is an emerging restrictive procedure.12 SG can be performed as the first of a two-stage operation in patients at high risk of death13,14 or as a definitive surgical procedure.15 It has shown good results with regard to weight loss16 and glycemic control in various studies.6,14,16,17 The potential advantages of SG include a lower probability of vitamin and mineral deficiencies than RYGB, access to the entire intestinal tract, a lack of need for a subcutaneous access port and a lower risk of intestinal obstruction. In addition, SG can be performed in patients who have inflammatory bowel disease or have undergone previous bowel surgery, and it can be easily converted into a RYGB.12,15 Both SG and RYGB can be performed with or without the placement of a Silastic® ring.18,19
Metabolic control can be achieved with gastric restrictive procedures such as vertical banded gastroplasty,5 adjustable gastric banding20 and, more recently, SG.17 However, previous studies have found that glucose homeostasis is affected by various intestinal mechanisms that are only altered by bariatric surgery procedures that include an intestinal element,21 such as RYGB.22-24 A systematic review showed resolution of T2DM in 76.8% of patients undergoing RYGB and improvement of glycemic control in 86% of patients.25 Of the criteria used to diagnose the metabolic syndrome, fasting glucose levels26 are the first to return to normal in patients who have undergone Silastic® ring sleeve gastrectomy. The achievement of normoglycemia after bariatric procedures results from multiple changes that occur postoperatively,6,27,28 such as dietary control,20,21 decreased plasma ghrelin levels,29,30 weight loss, reduction of body fat,6 and the release of gastrointestinal hormones that interfere with the function of pancreatic β cells (incretins).23,24,31,32
The main purpose of this study was to assess weight loss in morbidly obese patients undergoing SRSG as well as to evaluate the effects of the SRSG procedure on glucose homeostasis.
This was a prospective clinical study. It was approved by the Research Ethics Committee of the University Hospital of the Federal University of Espírito Santo, Brazil (protocol no. 049/06). To obtain a homogenous sample, we adopted the following inclusion criteria: we included female patients 20-60 years with a BMI of 40-45 who agreed to provide written informed consent. The exclusion criteria included the following: secondary obesity, alcohol or drug use, presence of a severe psychiatric disorder, binge-eating disorders and previous stomach or bowel surgery.
Thirty-three female patients were included in the present study. The patients had a mean age of 36.7 ± 9.4 years, a mean BMI of 42.33 ± 1.5 and a mean waist circumference of 118.7 ± 5.98 cm. The mean preoperative fasting glucose level of the included patients was 108.5 ± 43.76 mg/dl. The diagnoses of diabetes and GI were based on the criteria adopted by the Brazilian Diabetes Society.33 T2DM was found in 11 patients (33.3%), and GI was found in 4 patients (12.1%). Therefore, 45.4% of the morbidly obese patients analyzed in the present study presented with elevated fasting glucose levels. Most of the diabetic patients were treated with oral hypoglycemic agents. Assessment was performed one year (range: 12 to 14 months) after surgery.
The surgical procedures were performed between December 08, 2006 and July 27, 2007 at Hospital at Hospital Universitário Cassiano Antonio Moraes da Universidade Federal do Espírito Santo (HUCAM/UFES, Cassiano Antonio Moraes University Hospital, Federal University of Espírito Santo). The procedures were performed by the same surgeon using similar anesthetic techniques (epidural anesthesia combined with general anesthesia).
Silastic® ring sleeve gastrectomy was performed as follows: the vessels of the greater curvature of the body and fundus of the stomach were ligated, and the fundus and part of the body of the stomach was resected using a linear stapler (80 mm, Tyco®). A 32-Fr tube was then used to calibrate the diameter of the remaining stomach and a 6.2-cm Silastic® ring was placed around the stomach, 5.0 cm below the esophagogastric junction.
The staple lines were then oversewn, and a methylene blue test was performed to verify that the staple line was secure. The patients were given a liquid diet on the first postoperative day and were discharged on the third postoperative day. They received dietary guidance and instructions regarding physical activities and were also prescribed vitamin and mineral supplements.
Weight loss, BMI reduction and waist circumference reduction were assessed. The percentage of excess BMI lost was calculated using the following formula: excess BMI loss = (preoperative BMI - current BMI) ÷ (preoperative BMI - 25) × 100.34 Glucose homeostasis was assessed through the measurement of fasting plasma glucose levels and an oral glucose tolerance test, after hipoglicemic agents were discontinued.
The results of the descriptive analyses were expressed as means, standard deviations, medians, frequency (%), minimum values and maximum values. The Wilcoxon matched pairs test was used to analyze the differences between pre-treatment and post-treatment plasma glucose levels. The McNemar test was used to compare the rates of T2DM and GI pre- and post-treatment. Statistical significance was set at p < 0.05.
Although it was not the main focus of the present study, it was noteworthy that two patients (6%) developed a fistula at the staple line at the level of the cardiac notch. Both patients required reoperation. One patient died, and the other underwent total gastrectomy, which led to the resolution of the fistula. These patients, neither of whom had T2DM or GI, were excluded from the postoperative analysis. Therefore, a total of 31 patients were included in the postoperative analysis. In these 31 patients, the mean weight decreased from 107.69 ± 6.57 kg to 70.52 ± 9.36 kg (p < 0.001). BMI decreased from 42.27 ± 1.46 kg/m2 to 27.4 ± 2.42 kg/m2 (p < 0.001), a reduction of 35.18% (Figure 1). Waist circumference decreased from 118.42 ± 5.71 cm to 89.87± 6.66 cm (p < 0.001) (Figure 2). The percentage of excess BMI loss was 86.51 ± 14.2% (46.6 - 108.5%).
The reduction in glucose levels was also significant (p < 0.001), with mean plasma glucose values decreasing from a preoperative mean of 109.77 ± 44.19 to a postoperative mean of 80.94 ± 6.3 mg/dl (Figure 3). This reduction was more marked in patients with T2DM and/or GI.
SRSG proved to be effective in promoting the resolution of T2DM and GI in affected patients (p < 0.001) (Figure 4). All patients were able to discontinue the use of oral hypoglycemic agents, insulin, or both, during the follow-up period (Table 1).
Obesity can cause deleterious effects on many organic functions and impair health and quality of life.35 The SG procedure is used with increasing frequency in bariatric surgery.12-17 However, there are few prospective clinical studies in the literature that compare this emerging procedure with the gold standard, RYGB.12,17
In the present study, SG was performed, and a Silastic® ring was placed around the stomach. We thus created a small, functional stomach, much like that created during traditional vertical gastroplasty. We also removed the principal site of ghrelin production, which gave the SRSG the characteristics of both bariatric and endocrine surgery.19 The removal of the principal site of ghrelin production led to a decrease in ghrelin levels, adding a hormonal component to SRSG that other restrictive procedures lack, such as adjustable gastric banding.31 Some authors have reported the use of added restriction in SG to increase the intensity and duration of weight loss.19,36,37
Some researchers have reported that SG is less risky than RYGB.12-14 In our sample, however, serious complications and death occurred after SG.
We observed significant weight loss, BMI reduction, waist circumference reduction and excess BMI loss in this study. These findings are in accordance with several studies12,15,17 but are in disagreement with others13,14 that regarded SG as simply the first stage of a definitive surgery. The promising results of the present study are most likely due (at least in part) to the judicious inclusion criteria we chose, which excluded patients with a BMI greater than 45 and patients who had undergone prior stomach or bowel surgery.
In these patient populations, the results of bariatric surgery have admittedly been less effective. Other factors that might have contributed to the promising results of the present study include the calibration of the remaining stomach using a 32-Fr tube and the placement of a Silastic® ring. In other studies in which weight loss was less pronounced, tubes of a larger caliber were used39, and a Silastic® ring was not placed.13,14
Resolution of T2DM has been well-documented in various types of bariatric surgery.5 In two studies of patients undergoing SG, control of T2DM was achieved in 80% of patients.13,14 This remission rate was higher than the rate that is commonly reported for restrictive procedures like vertical banded gastroplasty5 and adjustable gastric banding.20 This rate, however, is lower than that obtained with RYGB9,26 and biliopancreatic diversion procedures.21
In the present study, all of the patients with T2DM or GI went into clinical remission, a surprising result also found in another study.17 Because SRSG is basically a restrictive procedure that does not affect incretin expression, it was expected that the results obtained from this procedure would be inferior to those obtained from procedures in which a duodenal switch is performed with regard to glucose homeostasis.23,24,27,28 In the present study, glucose levels might have decreased as a result of the marked weight loss observed in all patients, which led to increased insulin sensitivity and decreased leptin production, and thus to increased insulin secretion and remission of GI and T2DM, as noted in previous studies.6,39 Other hormones produced in adipose tissue might also have been involved in the notable rate of glycemic control observed in the present study.
It is notable, however, that only one patient who underwent surgery in the present study used insulin preoperatively. The other 14 patients with GI or T2DM were treated with oral hypoglycemic agents.
According to previous studies, remission or dietary control of GI/T2DM is more likely to be possible in these patients after bariatric surgery than patients who required insulin preoperatively.22,24
The greatest limitations of the present study were the short follow-up period and the lack of a control group for comparison. However, the study sample was comprised of patients with similar baseline characteristics, namely age, BMI, waist circumference and preoperative fasting glucose levels. The similar baselines among patients is an advantage for this study over previous studies in which the patient populations were not similar at baseline,12 and the patients often had BMIs of < 4012,15,17 and/or > 50.12-17
The surgical procedure in the present study, SRSG, resulted in marked weight loss, BMI reduction, waist circumference reduction, excess BMI loss, improved glucose homeostasis and remission of GI and T2DM in our study population. Further studies need to evaluate SRSG with a longer follow-up period, a control group and the inclusion of other variables, such as hormonal changes, to solidify SRSG's standing as a bariatric surgery procedure.
The authors would like to thank Ms Ilma O'Reilly for her aid in recruiting and monitoring the patients who participated in the present study.
1. North American Association for the Study of Obesity (NAASO) and National Heart, Lung, and Blood Institute (NHLBI). The Practical Guide: Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. NIH Publication #00-4084, Oct 2000. [ Links ]
2. Must A, Spadano J, Coakley EH, Field AE, Colditz G, Dietz WH. The disease burden associated with overweight and obesity. JAMA. 1999;282:1523-9. [ Links ]
3. Gomes MB, Giannella Neto D, De Mendonça E, Tambascia MA, Fonseca RM, Réa RR, et al. Prevalência de sobrepeso e obesidade em pacientes com diabetes mellitus do tipo 2 no Brasil: Estudo multicêntrico nacional. Arq Bras Endocrinol Metab. 2006;50:136-44. [ Links ]
4. Venkat Narayan KM, Gregg EW, Fagot-Campagna A, Engelgau MM, Vinicor F. Diabetesa common, growing, serious, costly, and potentially preventable public health problem. Diabetes Res Clin Pract. 2000; 50 Suppl 2:S77-84. [ Links ]
5. Sjöström L, Narbro K, Sjöström D, Karason K, Larsson B, Wedel H, et al. Effects of bariatric surgery on mortality in swedish obese subjects. N Engl J Med. 2007;357:741-52. [ Links ]
6. Bose M, Oliván B, Teixeira J, Pi-Sunyer FX, Laferrère B. Do incretins play a role in the remission of type 2 diabetes after gastric bypass surgery: what are the evidence? Obes Surg. 2009;19:217-29. [ Links ]
7. Christou NV, Sampalis JS, Liberman M, Look D, Auger S, McLean APH, et al. Surgery decreases long-term mortality, morbidity, and health care use in morbidly obese patients. Ann Surg. 2004;240:416-23; discussion 423-4. [ Links ]
8. Adams TD, Gress RE, Smith SC, Halverson RC, Simper SC, Rosamond WD, et al. Long-term mortality after gastric bypass surgery. N Engl J Med. 2007;357:753-61. [ Links ]
9. Pories WJ, Swanson MS, MacDonald KG, Long SB, Morris PG, Brown BM, et al. Who would have thought it? An operation proves to be the most effective therapy for adult-onset diabetes mellitus. Ann Surg. 1995;222:339-50; discussion 350-2. [ Links ]
10. Buchwald H, Buchwald JN. Evolution of operative procedures for the management of morbid obesity 1950-2000. Obes Surg. 2002;12:705-17. [ Links ]
11. Fobi MA. Why the operation I prefer is silastic ring banded gastric bypass. Obes Surg. 1991;1:423-6. [ Links ]
12. Lee CM, Cirangle PT, Jossart GH. Vertical gastrectomy for morbid obesity in 216 patients: report of two-year results. Surg Endosc. 2007;21:1810-6. [ Links ]
13. Cottam D, Qureshi FG, Mattar SG, Sharma S, Holover S, Bonanomi G, et al. Laparoscopic sleeve gastrectomy as an initial weight-loss procedure for high-risk patients with morbid obesity. Surg Endosc. 2006;20:859-63. [ Links ]
14. Silecchia G, Boru C, Pecchia A, Rizzelo M, Casella G, Leonetti F, et al. Effectiveness of laparoscopic sleeve gastrectomy (first stage of biliopancreatic diversion with duodenal switch) on co-morbidities in super-obese high-risk patients. Obes Surg. 2006;16:1138-44. [ Links ]
15. Baltasar A, Serra C, Perez N, Bou R, Bengochea M, Ferri L. Laparoscopic sleeve gastrectomy: a multi-purpose bariatric operation. Obes Surg. 2005;15:1124-8. [ Links ]
16. Moon Han S, Kim WW, Oh JH. Results of laparoscopic sleeve gastrectomy (LSG) at 1 year in morbidly obese Korean patients. Obes Surg. 2005;15:1469-75. [ Links ]
17. Vidal J, Ibarzabal A, Romero F, Delgado S, Momblán D, Flores L, et al. Type 2 diabetes mellitus and the metabolic syndrome following sleeve gastrecmomy in severely obese subjects. Obes Surg. 2008;18:1077-82. [ Links ]
18. Valezi AC, Brito EM, Souza JCL, Guariente ALM, Emori FT, Lopes VCH. A importância do anel de silicone na derivação gástrica em Y de Roux para o tratamento da obesidade. Rev Col Bras Cir. 2008;35:18-22. [ Links ]
19. Miguel GPS, Azevedo JLMC, Carvalho PS, Fukuda T, Novaes MA, Kumaira SB, et al. Baroendocrine Mason operation. Abstract. Obes Surg. 2006;16:1020-1. [ Links ]
20. Dixon JB, O'Brien PE, Playfair J, Chapman L, Schachter LM, Skinner S, et al. Adjustable gastric banding and conventional therapy for the type 2 diabetes: a randomized controlled trial. JAMA. 2008;299:316-23. [ Links ]
21. Scopinaro N, Adami GF, Marinari GM, Gianetta E, Traverso E, Friedman, et al. Biliopancreatic diversion. World J Surg. 1998;22:936-46. [ Links ]
22. Schauer PR, Burguera B, Ikramuddin S, Cottam D, Gourash W, Hamad G, et al. Effect of laparoscopic Roux-en Y gastric bypass on type 2 diabetes mellitus. Ann Surg. 2003;238:467-85. [ Links ]
23. Cummings DE, Overduin J, Foster-Schubert KE. Gastric bypass for obesity: mechanisms of weight loss and diabetes resolution. J Clin Endocrinol Metab. 2004;89:2608-15. [ Links ]
24. Rubino F, Forgione A, Cummings DE, Vix M, Gnuli D, Mingrone G, et al. The mechanism of diabetes control after gastrointestinal bypass surgery reveals a role of the proximal small intestine in the pathophysiology of type 2 diabetes. Ann Surg. 2006;244:741-9. [ Links ]
25. Buchwald H, Avidor Y, Braunwald E, Jensen MD, Pories W, Fahrbach K, et al. Bariatric surgery: a systematic review and meta-analysis. JAMA. 2004;292:1724-37. [ Links ]
26. Carvalho OS, Barelli MC, Moreira CLCB, Oliveira FH, Guzzo MF, Miguel GPS, et al. Cirurgia bariátrica cura síndrome metabólica? Arq Bras Endocrinol e Metab. 2007;51:79-85. [ Links ]
27. Mason EE. The mechanism of surgical treatment of type 2 diabetes. Obes Surg. 2005;15:459-61. [ Links ]
28. Martins MVD, Souza AAP. Mecanismos cirúrgicos de controle do diabetes mellitus tipo 2 após cirurgia bariátrica. Rev Col Bras Cir. 2007;34:343-6. [ Links ]
29. Langer FB, Reza Hoda MA, Bohdjalian A, Felberbauer FX, Zacherl J, Wenzl E, et al. Sleeve gastrectomy and gastric banding: effects on plasma ghrelin levels. Obes Surg. 2005;15:1024-9. [ Links ]
30. Nakazato M, Murakami N, Date Y, Kojima M, Matsuo H, Kangawa K, et al. A role for ghrelin in the central regulation of feeding. Nature. 2001;409:194-8. [ Links ]
31. Pories WJ, Albrecht RJ. Etiology of type II diabetes mellitus: role of the foregut. World J Surg. 2001;25:527-31. [ Links ]
32. Drucker DJ. Biological actions and therapeutic potential of the glucagon-like peptides. Gastroenterology. 2002;122:531-44. [ Links ]
33. Sociedade Brasileira de Diabetes. Diretrizes: tratamento e acompanhamento do diabetes mellitus. 2007. Diagraphic Editora. [ Links ]
34. Deitel M, Gawdat K, Melissas J. Reporting weight loss 2007. Obes Surg. 2007;17:565-8. [ Links ]
35. Costa D, Barbalho MC, Miguel GPS, Forti EMP, Azevedo JLMC. The impact of obesity on pulmonary function in adult women. Clinics. 2008;63: 719-24. [ Links ]
36. Cai J, Zheng C, Xu L, Chen D, Li X, Wu J, et al. Therapeutic effects of sleeve gastrectomy plus gastric remnant banding on weigth reduction and gastric dilatation: na animal study. Obes Surg. 2008;18:1411-7. [ Links ]
37. Greenstein AJ, Vine AJ, Jacob BP. Video. When sleeve gastrectomy fails: adding a laparoscopic adjustable gastric band to increase restriction. Surg Endosc. 2009;23:884. Epub 2009 Jan 1. [ Links ]
38. Braghetto I, Korn O, Valladares H, Gutiérrez L, Csendes A, Debandi A, et al. Laparoscopic sleeve gastrectomy: surgical technique, indications and clinical results. Obes Surg. 2007;17:1442-50. [ Links ]
39. Meirelles K, Ahmed T, Culnan DM, Lynch CJ, Lang CH, Cooney R. Mechanisms of glucose homeostasis after Roux-en-Y gastric bypass surgery in the obese, insulin-resistant Zucker rat. Ann Surg. 2009;249:277-85. [ Links ]
Received for publication on May 19, 2009
Accepted for publication on August 11, 2009