title: Gastric volume reduction is essential for the remission of type 2 diabetes mellitus after bariatric surgery in nonobese rats.
abstract: BACKGROUND
  Roux-en-Y gastric bypass (RYGB) has shown positive outcomes in the remission of type 2 diabetes (T2D) and weight loss in obese patients by inhibiting food intake and nutrient absorption as well as inducing favorable hormonal changes. The purpose of the present study was to investigate whether gastric volume reduction is still required in addition to intestinal bypass for the purpose of T2D remission in nonobese patients.
  
  
  METHODS
  University Medical Center.
  
  
  METHODS
  Nonobese T2D Goto-Kakizaki rats were employed in the study. All rats were randomized into 3 groups according to the surgical procedure performed, including (1) RYGB, (2) duodeno-jejunal bypass (DJB) without gastric volume reduction, and (3) sham surgery (control). In addition, age-matched Wistar rats were adopted as normal nondiabetic controls. Weight, food intake, fasting plasma glucose, and intraperitoneal glucose tolerance test were measured in vivo before and 2, 4, and 8 weeks after the treatment. Whole body metabolic parameters including respiratory exchange ratio, energy expenditure, and activities were also recorded in all animals at the third week postoperatively.
  
  
  RESULTS
  Compared with DJB and sham animals, the RYGB group had lower weight, less food intake, lower fasting plasma glucose, and improved glucose tolerance at all measuring time points postoperatively. By measuring whole body metabolic parameters, we found that RYGB, but not DJB, increased metabolic rate manifested by increased energy expenditure but less activity at night. In the meantime, respiratory exchange ratio was lower in RYGB group than in the other 3 groups at daytime, meaning adipose tissue became the main source of internal energy production during the resting phase in the group.
  
  
  CONCLUSIONS
  For nonobese T2D patients, adding gastric volume reduction to intestine bypass gave better efficacy in remission of T2D by increasing metabolic rate and adipolysis, especially during the resting period.
authors.affiliation: Center for Metabolic and Bariatric Surgery, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China.
authors.forename: Xiong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Center for Metabolic and Bariatric Surgery, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yu
authors.affiliation: Center for Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Yang
authors.affiliation: Center for Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China.
authors.forename: Zhengdong
authors.initials: Z
authors.lastname: Qiao
authors.affiliation: Center for Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Cao
authors.affiliation: Center for Metabolic and Bariatric Surgery, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China; Center for Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China. Electronic address: zhangpg@yahoo.com.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
mesh_terms: D017667:Adipocytes / Q000473:pathology; D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000473:pathology / Q000601:surgery*; D004386:Duodenum / Q000601:surgery; D004734:Energy Metabolism / Q000502:physiology; D005215:Fasting / Q000097:blood; D015390:Gastric Bypass / Q000379:methods*; D015391:Gastroplasty / Q000379:methods*; D018149:Glucose Intolerance / Q000209:etiology; D005951:Glucose Tolerance Test; D007328:Insulin / Q000378:metabolism; D007583:Jejunum / Q000601:surgery; D011183:Postoperative Complications; D011897:Random Allocation; D011919:Rats, Inbred Strains
chemical_list: D007328:Insulin
keywords: Bariatric surgery; Duodeno-jejunal bypass; Energy expenditure; Roux-en Y gastric bypass; Type 2 diabetes