title: Accelerated gastric emptying but no carbohydrate malabsorption 1 year after gastric bypass surgery (GBP).
abstract: BACKGROUND
  Following gastric bypass surgery (GBP), there is a post-prandial rise of incretin and satiety gut peptides. The mechanisms of enhanced incretin release in response to nutrients after GBP is not elucidated and may be in relation to altered nutrient transit time and/or malabsorption.
  
  
  METHODS
  Seven morbidly obese subjects (BMI = 44.5 ± 2.8 kg/m(2)) were studied before and 1 year after GBP with a D: -xylose test. After ingestion of 25 g of D: -xylose in 200 mL of non-carbonated water, blood samples were collected at frequent time intervals to determine gastric emptying (time to appearance of D: -xylose) and carbohydrate absorption using standard criteria.
  
  
  RESULTS
  One year after GBP, subjects lost 45.0 ± 9.7 kg and had a BMI of 27.1 ± 4.7 kg/m(2). Gastric emptying was more rapid after GBP. The mean time to appearance of D: -xylose in serum decreased from 18.6 ± 6.9 min prior to GBP to 7.9 ± 2.7 min after GBP (p = 0.006). There was no significant difference in absorption before (serum D: -xylose concentrations = 35.6 ± 12.6 mg/dL at 60 min and 33.9 ± 9.1 mg/dL at 180 min) or 1 year after GBP (serum D: -xylose = 31.5 ± 18.1 mg/dL at 60 min and 27.2 ± 11.9 mg/dL at 180 min).
  
  
  CONCLUSIONS
  These data confirm the acceleration of gastric emptying for liquid and the absence of carbohydrate malabsorption 1 year after GBP. Rapid gastric emptying may play a role in incretin response after GBP and the resulting improved glucose homeostasis.
authors.affiliation: New York Obesity Nutrition Research Center, New York, NY, USA.
authors.forename: Gary
authors.initials: G
authors.lastname: Wang
authors.forename: Keesandra
authors.initials: K
authors.lastname: Agenor
authors.forename: Justine
authors.initials: J
authors.lastname: Pizot
authors.forename: Donald P
authors.initials: DP
authors.lastname: Kotler
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Harel
authors.forename: Bart J
authors.initials: BJ
authors.lastname: Van Der Schueren
authors.forename: Iliana
authors.initials: I
authors.lastname: Quercia
authors.forename: James
authors.initials: J
authors.lastname: McGinty
authors.forename: Blandine
authors.initials: B
authors.lastname: Laferrère
mesh_terms: D000328:Adult; D004040:Dietary Carbohydrates / Q000378:metabolism*; D005260:Female; D015390:Gastric Bypass; D005746:Gastric Emptying; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D054795:Incretins / Q000378:metabolism; D007408:Intestinal Absorption; D007421:Intestine, Small / Q000378:metabolism* / Q000503:physiopathology / Q000601:surgery; D008286:Malabsorption Syndromes / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000378:metabolism* / Q000503:physiopathology / Q000601:surgery; D019518:Postprandial Period; D015431:Weight Loss
chemical_list: D004040:Dietary Carbohydrates; D006442:Glycated Hemoglobin; D054795:Incretins; C517652:hemoglobin A1c protein, human