Clinical trial NCT05621460: The Effect of Water Carbonation on Orthostatic Tolerance
Official title: The Effect of Water Carbonation on Orthostatic Tolerance
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Orthostatic Hypotension
Syncope
Vasovagal Syncope
Keywords: Tilt table
Osmopressor reflex
Gastropressor reflex
Lead sponsor: Simon Fraser University
Sponsor class: OTHER
First posted: 2022-11-18
Enrollment: 25
Sex: ALL
Minimum age (years): 19
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Each participant will complete the test for every condition (3 tests per participant, order of treatment randomized).
Primary purpose: TREATMENT

Brief summary: The primary purpose of this investigation is to determine whether water carbonation can improve orthostatic tolerance in healthy control volunteers. Orthostatic tolerance refers to the ability to maintain an adequate blood pressure when standing. In some individuals blood pressure can fall when standing, predisposing to dizzy spells or fainting episodes. Drinking water can boost blood pressure and making fainting episodes less likely. However, it is not clear whether the carbonation of the water has any further impact on the blood pressure response. This is important because it may be that carbonated water expands the stomach (gastric distension), provoking an increase in sympathetic activity. The increase in sympathetic nervous system activity boosts blood pressure. Resolving this question would have important implications for patients with syncope. This study will test whether carbonated water will have any further impact on blood pressure than the already known effect of non-carbonated water.

Detailed description: The primary purpose of this investigation is to determine whether water carbonation can improve orthostatic tolerance in healthy control volunteers. Orthostatic tolerance refers to the ability to maintain an adequate blood pressure when standing \[1\]. In some individuals blood pressure can fall when standing, predisposing to dizzy spells or fainting episodes \[1\]. Drinking water can boost blood pressure and making fainting episodes less likely \[2-8\]. However, it is not clear whether the carbonation of the water has any further impact on the blood pressure response \[9,10\]. This is important because it may be that carbonated water expands the stomach (gastric distension), provoking an increase in sympathetic activity. The increase in sympathetic nervous system activity boosts blood pressure. Resolving this question would have important implications for patients with syncope. This study will test whether carbonated water will have any further impact on blood pressure than the already known effect of non-carbonated water.

Volunteers (n=25) will be asked to undergo a "tilt test" to assess cardiovascular reflex control and orthostatic tolerance (measured as time to presyncope, or near fainting, in minutes). It has been previously shown that this technique to be reproducible, reliable, and to have high sensitivity and specificity for differentiating persons with differing orthostatic tolerance, or for examining the effects of interventions aimed at improving orthostatic tolerance \[4,6,11-18\].

Volunteers will undergo this test on three separate days. On each day participants will be asked to drink a glass of water: either a 50ml drink of room temperature water (control condition), a 500ml drink of flat (non-carbonated) room temperature water, or a 500ml drink of carbonated room temperature water. The study will be conducted in a randomised, single-blind fashion. The investigator responsible for terminating the test will be blinded as to the water condition on each test day, rendering the study single blind. It will not be possible to blind participants as to the carbonation of the water, however, participants will not be informed as to the hypothesised impact of the water conditions.

Eligibility criteria: Inclusion Criteria:

* healthy, English-speaking

Exclusion Criteria:

* pregnancy or suspected pregnancy, history of cardiovascular disease, history of neurological disease, history of recurrent fainting (≥ 2 episodes of fainting with loss of consciousness in the prior 6 months)

Primary outcomes:
measure: Orthostatic tolerance
timeFrame: 0-50 minutes
Secondary outcomes:
Other outcomes:
Locations:
city: Burnaby
country: Canada
facility: Simon Fraser University
state: British Columbia
Study officials:
affiliation: Professor, Biomedical Physiology and Kinesiology
name: Victoria E Claydon, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Hainsworth R, Claydon V E. Syncope and fainting: classification and physiological basis. In: Bannister R, Mathias CJ, eds. Autonomic failure: a textbook of clinical disorders of the autonomic nervous system. Oxford: Oxford University Press, 2006
citation: Mathias CJ. A 21st century water cure. Lancet. 2000 Sep 23;356(9235):1046-8. doi: 10.1016/S0140-6736(00)02723-9.
citation: Mathias CJ, Young TM. Water drinking in the management of orthostatic intolerance due to orthostatic hypotension, vasovagal syncope and the postural tachycardia syndrome. Eur J Neurol. 2004 Sep;11(9):613-9. doi: 10.1111/j.1468-1331.2004.00840.x.
citation: Schroeder C, Bush VE, Norcliffe LJ, Luft FC, Tank J, Jordan J, Hainsworth R. Water drinking acutely improves orthostatic tolerance in healthy subjects. Circulation. 2002 Nov 26;106(22):2806-11. doi: 10.1161/01.cir.0000038921.64575.d0.
citation: Brown CM, Barberini L, Dulloo AG, Montani JP. Cardiovascular responses to water drinking: does osmolality play a role? Am J Physiol Regul Integr Comp Physiol. 2005 Dec;289(6):R1687-92. doi: 10.1152/ajpregu.00205.2005. Epub 2005 Jul 21.
citation: Claydon VE, Schroeder C, Norcliffe LJ, Jordan J, Hainsworth R. Water drinking improves orthostatic tolerance in patients with posturally related syncope. Clin Sci (Lond). 2006 Mar;110(3):343-52. doi: 10.1042/CS20050279.
citation: Lu CC, Diedrich A, Tung CS, Paranjape SY, Harris PA, Byrne DW, Jordan J, Robertson D. Water ingestion as prophylaxis against syncope. Circulation. 2003 Nov 25;108(21):2660-5. doi: 10.1161/01.CIR.0000101966.24899.CB. Epub 2003 Nov 17.
citation: Boschmann M, Steiniger J, Hille U, Tank J, Adams F, Sharma AM, Klaus S, Luft FC, Jordan J. Water-induced thermogenesis. J Clin Endocrinol Metab. 2003 Dec;88(12):6015-9. doi: 10.1210/jc.2003-030780.
citation: May M, Jordan J. The osmopressor response to water drinking. Am J Physiol Regul Integr Comp Physiol. 2011 Jan;300(1):R40-6. doi: 10.1152/ajpregu.00544.2010. Epub 2010 Nov 3.
citation: Jordan J, Shannon JR, Black BK, Ali Y, Farley M, Costa F, Diedrich A, Robertson RM, Biaggioni I, Robertson D. The pressor response to water drinking in humans : a sympathetic reflex? Circulation. 2000 Feb 8;101(5):504-9. doi: 10.1161/01.cir.101.5.504.
citation: Al Shamma YMA, Hainsworth R. A quantitative comparison of the circulatory responses in humans to graded upright tilting and graded lower body negative pressure. Cardiogenic Reflexes (1987):431-432.
citation: Brown CM, Hainsworth R. Forearm vascular responses during orthostatic stress in control subjects and patients with posturally related syncope. Clin Auton Res. 2000 Apr;10(2):57-61. doi: 10.1007/BF02279892.
citation: Bush VE, Wight VL, Brown CM, Hainsworth R. Vascular responses to orthostatic stress in patients with postural tachycardia syndrome (POTS), in patients with low orthostatic tolerance, and in asymptomatic controls. Clin Auton Res. 2000 Oct;10(5):279-84. doi: 10.1007/BF02281110.
citation: Claydon VE, Hainsworth R. Salt supplementation improves orthostatic cerebral and peripheral vascular control in patients with syncope. Hypertension. 2004 Apr;43(4):809-13. doi: 10.1161/01.HYP.0000122269.05049.e7. Epub 2004 Feb 23.
citation: Claydon VE, Hainsworth R. Cerebral autoregulation during orthostatic stress in healthy controls and in patients with posturally related syncope. Clin Auton Res. 2003 Oct;13(5):321-9. doi: 10.1007/s10286-003-0120-8.
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