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Comment on: Laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass lead to equal changes in body composition and energy metabolism 17 months postoperatively: a prospective randomized trial
Surgery for Obesity and Related Diseases ] (2015) 00–00
Editorial comment
Comment on: Laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass lead to equal changes in body composition and energy metabolism 17 months postoperatively: a prospective randomized trial Schneider et al. [1], in a subgroup of a randomized controlled trial (RCT) [2], compared the outcomes of Rouxen-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), measuring the changes in body mass composition and energy expenditure, with the aim of comparing the differences between the types of procedure and assessing the predictive value of both measures on postoperative outcomes. The population studied was 85% female and 50% diabetic. What calls attention to this study is the fact that no difference in resting energy expenditure (REE) and body composition was found between the groups. The definition of type 2 diabetes mellitus (T2DM) was not reported; the subcohort of patients with T2DM could be insulin resistant only or very early in the disease process, considering that there may be aberrations of REE and body composition in T2DM regardless of the baseline body mass index as related to the control and duration of the disease [3]. Another issue is that truncal fat is more prevalent in those with T2DM than in metabolically healthy individuals, which was not found in the present study [4,5] Measurements of REE were performed at 17 ⫾ 5.6 months postoperatively. If measurements had been performed earlier as well, different results might have been found. From 3–12 months, REE is paradoxically higher [6], and there is a trend for stability after the nadir of weight loss is achieved. As the RYGB was more effective regarding weight loss (although the study was not powered to compare differences between both procedures), important differences probably would be reported earlier in follow-up and probably later as well, because positive SG outcomes have not been sustained in longer follow-up in RCTs or prospective case series [7–11]. There were no differences in the amount of fat distribution decrease in either group, probably because there was also no difference in baseline. This may be explained by the predominant female gender and probably by the lower severity of T2DM in these patients. Meal-induced thermogenesis is increased after food rerouting procedures [12,13], and it was not evaluated
in this study, which surely is a major component of better initial and late results of these procedures compared with mostly restrictive ones, which can boost energy expenditure. Several studies (RCTs and prospective and retrospective case series) with different follow-up periods have reported a better weight loss and metabolic outcomes for RYGB compared with SG. The Stampede study [7,8] reported a trend toward better weight loss in the RYGB group accompanied by a greater metabolic control at 1 and 3 years of follow-up, whereas patients in the SG group used 3 times more T2DM and cardiovascular medications after 12-month follow-up. In a substudy of that trial, Kashyap et al. [14] reported a comparable weight loss between both operations at 24 months, but with greater insulin sensitivity and better β-cell secretory function after the food rerouting procedure linked to a markedly decreased truncal fat. The explanation for why SG outcomes depend on the surgical technique performed remains elusive. Some try to explain the marked differences between the outcomes achieved in both procedures on the lack of standardization of the SG based on the bougie diameter or the distance from the pylorus for the first stapler firing. Differences in bougie size lead one to think that SG may be an enhanced restrictive operation (as some authors describe better weight loss with tighter sleeves), or perhaps applying the stapler to begin the confection of the sleeve 2 or 3 cm from the pylorus helps the SG sustain better long-term outcomes [15–17]. Other authors have found [10] that almost all patients in their cohort did not sustain T2DM control at longer follow-up (46 yr), even using the more liberal American Diabetes Association criteria [18] (glycated hemoglobin o7%; fasting plasma glucose o126 mg/dL), and this T2DM control is close to adjustable gastric banding when followed for a longer time. Is sustained meal-induced thermogenesis and different body mass composition associated with several other positive metabolic milieu improvements responsible for the better outcomes seen after RYGB
http://dx.doi.org/10.1016/j.soard.2015.09.002 1550-7289/r 2015 American Society for Metabolic and Bariatric Surgery. All rights reserved.
2
R. V. Cohen / Surgery for Obesity and Related Diseases ] (2015) 00–00
in the long term? When the Swiss group re-examines this cohort after a longer period, will they report different outcomes, even in this almost entirely female population? Finally, other interesting findings of this study should be emphasized. In a female population with severe obesity, although the number of patients was low, fat and lean mass loss were equal between the RYGB and SG groups, and there was no difference in REE or fat oxidation at 17 months, which is different from what is generally believed to happen. The results from energy metabolism and body composition failed to predict weight loss outcomes after both procedures (whether in T2DM patients or not). This study should be continued and long-term outcomes should be reported, whether clinical or addressing energy metabolism and mainly body composition. Randomized controlled trials comparing RYGB versus SG are important and necessary to establish the differences in results between these two techniques and refine their indications. So far, in the long-term, food rerouting operations seem to have a trend for better sustained weight loss and T2DM remission. Ricardo V. Cohen, M.D. The Center for Obesity and Diabetes Oswaldo Cruz German Hospital Sao Paulo, Brazil References [1] Schneider J, Peterli R, Gauss M, Slawik M, Peters T, Wölnerhanssenm BK. Laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass lead to equal changes in body composition and energy metabolism 17 months postoperatively: a prospective randomized trial. Surg Obes Relat Dis 2015. In press. [2] Peterli R, Borbély Y, Kern B, et al. Early results of the Swiss Multicentre Bypass or Sleeve Study (SM-BOSS): a prospective randomized trial comparing laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass. Ann Surg 2013;258(5):690–5. [3] Bloomgarden ZT. Diabetes and obesity: part 1. Diabetes Care 2007;30(12):3145–51.
[4] Stefan N, Häring HU. The metabolically benign and malignant fatty liver. Diabetes 2011;60(8):2011–7. [5] Stefan N, Kantartzis K, Machann J, et al. Identification and characterization of metabolically benign obesity in humans. Arch Intern Med 2008;168(15):1609–16. [6] Carrasco F, Papapietro K, Csendes A, et al. Changes in resting energy expenditure and body composition after weight loss following Rouxen-Y gastric bypass. Obes Surg 2007;17(5):608–16. [7] Schauer PR, Kashyap SR, Wolski K, et al. Bariatric surgery versus intensive medical therapy in obese patients with diabetes. N Engl J Med 2012;366(17):1567–76. [8] Schauer PR, Bhatt DL, Kirwan JP, et al. Bariatric surgery versus intensive medical therapy for diabetes—3-year outcomes. New Engl J Med 2014;370(21):2002–13. [9] Gloy VL, Briel M, Bhatt DL, et al. Bariatric surgery versus nonsurgical treatment for obesity: a systematic review and meta-analysis of randomised controlled trials. BMJ 2013;347:f5934. [10] Brethauer SA, Aminian A, Romero-Talamás H, et al. Can diabetes be surgically cured? Long-term metabolic effects of bariatric surgery in obese patients with type 2 diabetes mellitus. Ann Surg 2013;258 (4):628–37. [11] de Hollanda A, Ruiz T, Jiménez A, Flores L, Lacy A, Vidal J. Patterns of weight loss response following gastric bypass and sleeve gastrectomy. Obes Surg 2015;25(7):1177–83. [12] Werling M, Olbers T, Fändriks L, et al. Increased postprandial energy expenditure may explain superior long term weight loss after Rouxen-Y gastric bypass compared to vertical banded gastroplasty. PLoS One 2013;8(4):e60280. [13] Werling M, Fändriks L, Olbers T, et al. Roux-en-Y gastric bypass surgery increases respiratory quotient and energy expenditure during food intake. PLoS One 2015;10(6):e0129784. [14] Kashyap SR, Bhatt DL, Wolski K, et al. Metabolic effects of bariatric surgery in patients with moderate obesity and type 2 diabetes: analysis of a randomized control trial comparing surgery with intensive medical treatment. Diabetes Care 2013;36(8):2175–82. [15] Parikh M, Gagner M, Heacock L, Strain G, Dakin G, Pomp A. Laparoscopic sleeve gastrectomy: does bougie size affect mean % EWL? Short-term outcomes. Surg Obes Relat Dis 2008;4(4):528–33. [16] Spivak H, Rubin M, Sadot E, Pollak E, Feygin A, Goitein D. Laparoscopic sleeve gastrectomy using 42-French versus 32-french bougie: the first-year outcome. Obes Surg 2014;24(7):1090–3. [17] Toro JP, Lin E, Patel AD, et al. Association of radiographic morphology with early gastroesophageal reflux disease and satiety control after sleeve gastrectomy. J Am Coll Surg 2014;219(3):430–8. [18] American Diabetes Association. Standards of medical care in diabetes —2013. Diabetes Care 2013;36(Suppl 1):S11–66.
Editorial comment
Comment on: Laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass lead to equal changes in body composition and energy metabolism 17 months postoperatively: a prospective randomized trial Schneider et al. [1], in a subgroup of a randomized controlled trial (RCT) [2], compared the outcomes of Rouxen-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), measuring the changes in body mass composition and energy expenditure, with the aim of comparing the differences between the types of procedure and assessing the predictive value of both measures on postoperative outcomes. The population studied was 85% female and 50% diabetic. What calls attention to this study is the fact that no difference in resting energy expenditure (REE) and body composition was found between the groups. The definition of type 2 diabetes mellitus (T2DM) was not reported; the subcohort of patients with T2DM could be insulin resistant only or very early in the disease process, considering that there may be aberrations of REE and body composition in T2DM regardless of the baseline body mass index as related to the control and duration of the disease [3]. Another issue is that truncal fat is more prevalent in those with T2DM than in metabolically healthy individuals, which was not found in the present study [4,5] Measurements of REE were performed at 17 ⫾ 5.6 months postoperatively. If measurements had been performed earlier as well, different results might have been found. From 3–12 months, REE is paradoxically higher [6], and there is a trend for stability after the nadir of weight loss is achieved. As the RYGB was more effective regarding weight loss (although the study was not powered to compare differences between both procedures), important differences probably would be reported earlier in follow-up and probably later as well, because positive SG outcomes have not been sustained in longer follow-up in RCTs or prospective case series [7–11]. There were no differences in the amount of fat distribution decrease in either group, probably because there was also no difference in baseline. This may be explained by the predominant female gender and probably by the lower severity of T2DM in these patients. Meal-induced thermogenesis is increased after food rerouting procedures [12,13], and it was not evaluated
in this study, which surely is a major component of better initial and late results of these procedures compared with mostly restrictive ones, which can boost energy expenditure. Several studies (RCTs and prospective and retrospective case series) with different follow-up periods have reported a better weight loss and metabolic outcomes for RYGB compared with SG. The Stampede study [7,8] reported a trend toward better weight loss in the RYGB group accompanied by a greater metabolic control at 1 and 3 years of follow-up, whereas patients in the SG group used 3 times more T2DM and cardiovascular medications after 12-month follow-up. In a substudy of that trial, Kashyap et al. [14] reported a comparable weight loss between both operations at 24 months, but with greater insulin sensitivity and better β-cell secretory function after the food rerouting procedure linked to a markedly decreased truncal fat. The explanation for why SG outcomes depend on the surgical technique performed remains elusive. Some try to explain the marked differences between the outcomes achieved in both procedures on the lack of standardization of the SG based on the bougie diameter or the distance from the pylorus for the first stapler firing. Differences in bougie size lead one to think that SG may be an enhanced restrictive operation (as some authors describe better weight loss with tighter sleeves), or perhaps applying the stapler to begin the confection of the sleeve 2 or 3 cm from the pylorus helps the SG sustain better long-term outcomes [15–17]. Other authors have found [10] that almost all patients in their cohort did not sustain T2DM control at longer follow-up (46 yr), even using the more liberal American Diabetes Association criteria [18] (glycated hemoglobin o7%; fasting plasma glucose o126 mg/dL), and this T2DM control is close to adjustable gastric banding when followed for a longer time. Is sustained meal-induced thermogenesis and different body mass composition associated with several other positive metabolic milieu improvements responsible for the better outcomes seen after RYGB
http://dx.doi.org/10.1016/j.soard.2015.09.002 1550-7289/r 2015 American Society for Metabolic and Bariatric Surgery. All rights reserved.
2
R. V. Cohen / Surgery for Obesity and Related Diseases ] (2015) 00–00
in the long term? When the Swiss group re-examines this cohort after a longer period, will they report different outcomes, even in this almost entirely female population? Finally, other interesting findings of this study should be emphasized. In a female population with severe obesity, although the number of patients was low, fat and lean mass loss were equal between the RYGB and SG groups, and there was no difference in REE or fat oxidation at 17 months, which is different from what is generally believed to happen. The results from energy metabolism and body composition failed to predict weight loss outcomes after both procedures (whether in T2DM patients or not). This study should be continued and long-term outcomes should be reported, whether clinical or addressing energy metabolism and mainly body composition. Randomized controlled trials comparing RYGB versus SG are important and necessary to establish the differences in results between these two techniques and refine their indications. So far, in the long-term, food rerouting operations seem to have a trend for better sustained weight loss and T2DM remission. Ricardo V. Cohen, M.D. The Center for Obesity and Diabetes Oswaldo Cruz German Hospital Sao Paulo, Brazil References [1] Schneider J, Peterli R, Gauss M, Slawik M, Peters T, Wölnerhanssenm BK. Laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass lead to equal changes in body composition and energy metabolism 17 months postoperatively: a prospective randomized trial. Surg Obes Relat Dis 2015. In press. [2] Peterli R, Borbély Y, Kern B, et al. Early results of the Swiss Multicentre Bypass or Sleeve Study (SM-BOSS): a prospective randomized trial comparing laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass. Ann Surg 2013;258(5):690–5. [3] Bloomgarden ZT. Diabetes and obesity: part 1. Diabetes Care 2007;30(12):3145–51.
[4] Stefan N, Häring HU. The metabolically benign and malignant fatty liver. Diabetes 2011;60(8):2011–7. [5] Stefan N, Kantartzis K, Machann J, et al. Identification and characterization of metabolically benign obesity in humans. Arch Intern Med 2008;168(15):1609–16. [6] Carrasco F, Papapietro K, Csendes A, et al. Changes in resting energy expenditure and body composition after weight loss following Rouxen-Y gastric bypass. Obes Surg 2007;17(5):608–16. [7] Schauer PR, Kashyap SR, Wolski K, et al. Bariatric surgery versus intensive medical therapy in obese patients with diabetes. N Engl J Med 2012;366(17):1567–76. [8] Schauer PR, Bhatt DL, Kirwan JP, et al. Bariatric surgery versus intensive medical therapy for diabetes—3-year outcomes. New Engl J Med 2014;370(21):2002–13. [9] Gloy VL, Briel M, Bhatt DL, et al. Bariatric surgery versus nonsurgical treatment for obesity: a systematic review and meta-analysis of randomised controlled trials. BMJ 2013;347:f5934. [10] Brethauer SA, Aminian A, Romero-Talamás H, et al. Can diabetes be surgically cured? Long-term metabolic effects of bariatric surgery in obese patients with type 2 diabetes mellitus. Ann Surg 2013;258 (4):628–37. [11] de Hollanda A, Ruiz T, Jiménez A, Flores L, Lacy A, Vidal J. Patterns of weight loss response following gastric bypass and sleeve gastrectomy. Obes Surg 2015;25(7):1177–83. [12] Werling M, Olbers T, Fändriks L, et al. Increased postprandial energy expenditure may explain superior long term weight loss after Rouxen-Y gastric bypass compared to vertical banded gastroplasty. PLoS One 2013;8(4):e60280. [13] Werling M, Fändriks L, Olbers T, et al. Roux-en-Y gastric bypass surgery increases respiratory quotient and energy expenditure during food intake. PLoS One 2015;10(6):e0129784. [14] Kashyap SR, Bhatt DL, Wolski K, et al. Metabolic effects of bariatric surgery in patients with moderate obesity and type 2 diabetes: analysis of a randomized control trial comparing surgery with intensive medical treatment. Diabetes Care 2013;36(8):2175–82. [15] Parikh M, Gagner M, Heacock L, Strain G, Dakin G, Pomp A. Laparoscopic sleeve gastrectomy: does bougie size affect mean % EWL? Short-term outcomes. Surg Obes Relat Dis 2008;4(4):528–33. [16] Spivak H, Rubin M, Sadot E, Pollak E, Feygin A, Goitein D. Laparoscopic sleeve gastrectomy using 42-French versus 32-french bougie: the first-year outcome. Obes Surg 2014;24(7):1090–3. [17] Toro JP, Lin E, Patel AD, et al. Association of radiographic morphology with early gastroesophageal reflux disease and satiety control after sleeve gastrectomy. J Am Coll Surg 2014;219(3):430–8. [18] American Diabetes Association. Standards of medical care in diabetes —2013. Diabetes Care 2013;36(Suppl 1):S11–66.