Acute effect of excess water intake on blood pressure in healthy Individuals

Abstract

Background: It is a common habit in our country to drink excess water presuming that it keeps the kidney clean. The effect of excess water intake on hypertension is poorly known and there is some conflicting data in this regard. Thus we aimed to study the effect of excess water intake in short time on the blood pressure of healthy adult individuals. Materials and Methods: We conducted an open labeled, randomized, cross over trial with 12 healthy volunteers without any clinically significant disease. Each individual was asked to drink 2000ml of water over a period of 20 minutes after overnight fasting or observed without water intake according to a pre-randomized schedule after a washout period of 3 days. Results: In healthy adults (mean age 29.2±3.5yrs) after an intake of 2000ml over a period of 16.5±2.6min, there was a significant increase in systolic BP of 113.6±6.2 mmHg at 0 hrs to 127.7±9.6 mmHg at 15 min (p<0.001) and 120.7±5.5 mm Hg at 75 min (p<0.05). The diastolic BP also increased from 73.6±6.2 mmHg to 85.9±7.4 mmHg at 30 min (p< 0.01). There was no significant change in BP during no water intake phase. Conclusion: Excess water intake increases blood pressure in healthy individuals. The underlying mechanism and the long term effect of excess water intake need to be explored.