The Pressor Response to Water Drinking in Humans

Abstract

Background-Water drinking increases blood pressure profoundly in patients with autonomic failure and substantially in older control subjects. The mechanism that mediates this response is not known. Methods and Results-We studied the effect of drinking tap water on seated blood pressure in 47 patients with severe autonomic failure (28 multiple system atrophy [MSA], 19 pure autonomic failure patients [PAF]). Eleven older controls and 8 young controls served as control group. We also studied the mechanisms that could increase blood pressure with water drinking. Systolic blood pressure increased profoundly with water drinking, reaching a maximum of 33Ϯ5 mm Hg in MSA and 37Ϯ7 in PAF mm Hg after 30 to 35 minutes. The pressor response was greater in patients with more retained sympathetic function and was almost completely abolished by trimethaphan infusion. Systolic blood pressure increased by 11Ϯ2.4 mm Hg in elderly but not in young controls. Plasma norepinephrine increased in both groups. Plasma renin activity, vasopressin, and blood volume did not change in any group. Conclusions-Water drinking significantly and rapidly raises sympathetic activity. Indeed, it raises plasma norepinephrine as much as such classic sympathetic stimuli as caffeine and nicotine. This effect profoundly increases blood pressure in autonomic failure patients, and this effect can be exploited to improve symptoms due to orthostatic hypotension. Water drinking also acutely raises blood pressure in older normal subjects. The pressor effect of oral water is an important yet unrecognized confounding factor in clinical studies of pressor agents and antihypertensive medications.

Comparative effects of glucose and water drinks on blood pressure and cardiac function in older subjects with and without postprandial hypotension

“…Jordan et al. (2000) reported that the pressor response to water was exaggerated in patients with autonomic failure, some of whom had PPH (consistent with our observations) despite reduced release of noradrenaline, and postulated that this may reflect upregulation of vascular α 1 ‐adrenoreceptors and/or impaired baroreflex buffering (Jordan et al. 2000).…”

“…(2000) reported that the pressor response to water was exaggerated in patients with autonomic failure, some of whom had PPH (consistent with our observations) despite reduced release of noradrenaline, and postulated that this may reflect upregulation of vascular α 1 ‐adrenoreceptors and/or impaired baroreflex buffering (Jordan et al. 2000). While direct stimulation of sympathetic activity triggered by visceral stretch is likely to be important, as evidenced by the response to distension of the stomach with a balloon (van Orshoven et al.…”

“…This elevation in blood pressure was not associated with changes in SV, CO, EF, GLS, or SVR, but a modest reduction in HR, as has been reported in patients with autonomic neuropathy (Jordan et al. 2000; Cariga and Mathias 2001). It has been suggested that impairment of baroreflex function accounts for the pressor response to water in healthy older, but not young, subjects, as attested to by the modest fall in HR in comparison to the substantial rise in BP (Jordan et al.…”

“…It has been suggested that impairment of baroreflex function accounts for the pressor response to water in healthy older, but not young, subjects, as attested to by the modest fall in HR in comparison to the substantial rise in BP (Jordan et al. 2000). This concept is supported strongly by the outcome of studies in animals (McHugh et al.…”

Effects of Tailored Water Drinking on the Orthostatic Hypotension in the Elderly

“…를 차지한다는 보고 (Kasper et al, 2006) (Jordan et al, 2000), 고혈압이나 다른 신체적 합병증을 유발함으로써 사용 에 제한이 있다 (Jacob et al, 1997). 그러나 아직까지 비약물 적인 중재에 대한보고는 의학 뿐 아니라 간호학에서도 많지 않다.…”