title: Patients with chronic kidney disease have abnormal upper gastro-intestinal tract digestive function: A study of uremic enteropathy.
abstract: OBJECTIVE
  Chronic kidney disease (CKD) affects gastrointestinal (GI) function and results in numerous adaptive and maladaptive responses. Disruption of the colonic microbiome and its attendant consequences-the loss of gut barrier integrity and increased generation of uremic toxins-has become well-recognized. However, less attention has been paid to characterizing the mechanisms behind dysfunction of the upper GI tract, largely owing to the difficulty of studying small bowel function in vivo. This present study was designed to comprehensively describe upper GI function in those with advanced renal impairment.
  
  
  METHODS
  Thirty-five non-diabetic subjects (12 CKD stage 4/5 patients, 23 healthy controls) underwent detailed GI magnetic resonance imaging (MRI) in both fasted and fed states. Upper GI function was assessed by quantification of gastric emptying and intra-luminal small bowel water. Characterization of hydration and cardiovascular status was performed at baseline. Gut barrier integrity was assessed using serum endotoxin level.
  
  
  RESULTS
  Chronic kidney disease was associated with dysmotility (gastric half-emptying time 96 ± 32 vs 74 ± 27 min, P = 0.04) and reduced fasting and post-prandial small bowel water (36 ± 22 mL vs 78 ± 42 mL, P < 0.001), reflecting abnormal digestive secretion, and absorption. This was related to the degree of endotoxemia (r = -0.60, P = 0.04) and poorer symptom scores, but not to disease severity, arterial stiffness or hydration status.
  
  
  CONCLUSIONS
  Chronic kidney disease adversely affects digestive function. Abnormalities in digestive secretion and absorption may potentially have a broad impact in the prevention and treatment of both CKD and its complications. Further study is required to assess the factors that contribute to this dysfunction in a wider CKD population.
authors.affiliation: The Lilibeth Caberto Kidney Clinical Research Unit, London, Ontario, Canada.
authors.forename: Claire J
authors.initials: CJ
authors.lastname: Grant
authors.affiliation: Department of Renal Medicine, Royal Derby Hospital, Derby, UK.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Harrison
authors.affiliation: Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK.
authors.forename: Caroline L
authors.initials: CL
authors.lastname: Hoad
authors.affiliation: Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, UK.
authors.forename: Luca
authors.initials: L
authors.lastname: Marciani
authors.affiliation: Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK.
authors.forename: Penny A
authors.initials: PA
authors.lastname: Gowland
authors.affiliation: The Lilibeth Caberto Kidney Clinical Research Unit, London, Ontario, Canada.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: McIntyre
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001834:Body Water / Q000378:metabolism; D004063:Digestion; D004731:Endotoxins / Q000097:blood*; D005260:Female; D005746:Gastric Emptying; D005767:Gastrointestinal Diseases / Q000209:etiology* / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D007408:Intestinal Absorption; D007421:Intestine, Small / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D051436:Renal Insufficiency, Chronic / Q000150:complications*; D055815:Young Adult
chemical_list: D004731:Endotoxins
keywords: MRI; chronic kidney disease; gastrointestinal dysfunction; small bowel water