Blood pressure fluctuates in response to different factors, whether internal or external. Different body positions have been shown to cause changes in blood pressure however, there are in-built mechanisms that correct these fluctuations. A defect or delay in these inherent mechanisms to prevent postural-induced blood pressure changes results in postural hypotension. Volume depletion has been implicated as one of the conditions that bring about postural hypotension. The purpose of this study was to assess the impact of water intake on fluctuations in blood pressure induced by postural changes in healthy subjects. 20 female subjects were randomly divided into two groups: the control group and the test group, with each group having 10 subjects. Before the experiment commenced, the subjects were asked to rest by sitting comfortably for 15 minutes, and then their blood pressure and heart rate were measured, which served as the baseline. The test group was given 600 mL of water after baseline blood pressure and heart rate measurements. A digital sphygmomanometer was used for measuring the blood pressure and heart rate at 15 minutes of lying, 0, 5, 10 minutes of sitting, and 0, 5, 10 minutes of standing. The result showed a significant decrease in systolic blood pressure, diastolic blood pressure, and heart rate after 15 minutes of lying down compared to the baseline measurement, and a significant increase was also observed in the sitting position compared to the lying position in both groups. The blood pressure and heart rate recorded in all the positions in the test group were not significantly different from those of the control group. In conclusion, water intake did not alleviate the fluctuations in blood pressure and heart rate induced by postural changes.

Postural changes

Water

Blood pressure

Heart rate