title: Roux-en-Y gastric bypass alleviates hypertension and is associated with an increase in mid-regional pro-atrial natriuretic peptide in morbid obese patients.
abstract: OBJECTIVE
  To examine 24-h blood pressure (24BP), systemic haemodynamics and the effect of sodium intake on 24BP in obese patients before and after gastric bypass surgery [laparoscopic Roux-en-Y gastric bypass (LRYGB)], and to determine whether weight loss from LRYGB might be related to an increase in plasma concentrations of atrial natriuretic peptide.
  
  
  METHODS
  Twelve hypertensive and 12 normotensive morbidly obese patients underwent LRYGB: 24BP, systemic haemodynamics and mid-regional pro-atrial natriuretic peptide (MRproANP) were assessed before, 6 weeks and 12 months after surgery. The effect of high versus low sodium intake on 24BP was evaluated before and 12 months after LRYGB.
  
  
  RESULTS
  Six weeks after LRYGB, the average weight loss was 20 kg, with a further 21 kg weight loss 1 year after surgery. In hypertensive patients, 24BP was significantly reduced at 6 weeks, but not 1 year after LRYGB. However, antihypertensive medications were successively reduced from baseline to 1 year after surgery. In normotensive patients, there was no change in 24BP 6 weeks after LRYGB, but a tendency towards a reduction 1 year after the operation. Plasma concentrations of MRproANP were subnormal prior to surgery in hypertensive patients and increased by 77% 1 year after the operation. In normotensive patients, preoperative concentrations were normal and increased only by 6%. High sodium intake induced plasma volume expansion, increased stroke volume and cardiac output, but no significant change in 24BP - neither before nor after LRYGB.
  
  
  CONCLUSIONS
  LRYGB resulted in a significant 24BP reduction and a substantial increase in MRproANP plasma concentrations in hypertensive, obese patients 6 weeks after surgery, suggesting a causal link between obesity-hypertension and altered release/degradation of cardiac natriuretic peptides.
authors: aDepartment of Clinical Physiology and Nuclear Medicine bDepartment of Medicine, Koege Hospital, University of Copenhagen cDepartment of Clinical Biochemistry, Rigshospitalet dDepartment of Surgery, Division of Bariatric Surgery, Koege Hospital, University of Copenhagen, Copenhagen eDepartment of Bariatric Surgery, Aleris-Hamlet, Soeborg, Denmark fClinical Institute, University of Aarhus gDepartment of Surgical Gastroenterology, Hvidovre Hospital hDepartment of Clinical Biochemistry, Koege Hospital, University of Copenhagen, Copenhagen, Denmark.
authors: Peter K
authors: PK
authors: Bonfils
authors: Mustafa
authors: M
authors: Taskiran
authors: Morten
authors: M
authors: Damgaard
authors: Jens P
authors: JP
authors: Goetze
authors: Andrea K
authors: AK
authors: Floyd
authors: Peter
authors: P
authors: Funch-Jensen
authors: Viggo B
authors: VB
authors: Kristiansen
authors: Mikael
authors: M
authors: Støckel
authors: Pierre N
authors: PN
authors: Bouchelouche
authors: Niels
authors: N
authors: Gadsbøll
mesh_terms: D000328:Adult; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000378:metabolism*; D001794:Blood Pressure; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000601:surgery*; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000453:epidemiology / Q000601:surgery*; D013997:Time Factors; D015431:Weight Loss
chemical_list: C552580:midregional pro-atrial natriuretic peptide, human; D009320:Atrial Natriuretic Factor