title: Water drinking as a treatment for orthostatic syndromes.
abstract: OBJECTIVE
  Water drinking increases blood pressure in a substantial proportion of patients who have severe orthostatic hypotension due to autonomic failure. We tested the hypothesis that water drinking can be used as a practical treatment for patients with orthostatic and postprandial hypotension, as well as those with orthostatic tachycardia.
  
  
  METHODS
  We studied the effect of drinking water on seated and standing blood pressure and heart rate in 11 patients who had severe orthostatic hypotension due to autonomic failure and in 9 patients who had orthostatic tachycardia due to idiopathic orthostatic intolerance. We also tested the effect of water drinking on postprandial hypotension in 7 patients who had autonomic failure. Patients drank 480 mL of tap water at room temperature in less than 5 minutes.
  
  
  RESULTS
  In patients with autonomic failure, mean (+/- SD) blood pressure after 1 minute of standing was 83 +/- 6/53 +/- 3.4 mm Hg at baseline, which increased to 114 +/- 30/66 +/- 18 mm Hg (P <0.01) 35 minutes after drinking. After a meal, blood pressure decreased by 43 +/- 36/20 +/- 13 mm Hg without water drinking, compared with 22 +/- 10/12 +/- 5 mm Hg with drinking (P <0.001). In patients with idiopathic orthostatic intolerance, water drinking attenuated orthostatic tachycardia (123 +/- 23 beats per minute) at baseline to 108 +/- 21 beats per minute after water drinking ( P <0.001).
  
  
  CONCLUSIONS
  Water drinking elicits a rapid pressor response in patients with autonomic failure and can be used to treat orthostatic and postprandial hypotension. Water drinking moderately reduces orthostatic tachycardia in patients with idiopathic orthostatic intolerance. Thus, water drinking may serve as an adjunctive treatment in patients with impaired orthostatic tolerance.
authors.affiliation: Nathan Blaser Shy-Drager Research Program, Autonomic Dysfunction Center, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Shannon
authors.forename: Andre
authors.initials: A
authors.lastname: Diedrich
authors.forename: Italo
authors.initials: I
authors.lastname: Biaggioni
authors.forename: Jens
authors.initials: J
authors.lastname: Tank
authors.forename: Rose Marie
authors.initials: RM
authors.lastname: Robertson
authors.forename: David
authors.initials: D
authors.lastname: Robertson
authors.forename: Jens
authors.initials: J
authors.lastname: Jordan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001342:Autonomic Nervous System Diseases / Q000628:therapy*; D001794:Blood Pressure; D004326:Drinking; D005260:Female; D005502:Food; D006339:Heart Rate; D006801:Humans; D007024:Hypotension, Orthostatic / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011187:Posture