Cold Pressor Test in Borderline Hypertensive University Students

Abstract

Background Hyperactive sympathetic reaction is an important factor for development of hypertension in young individuals. The stress induced increase in blood pressure recovers within very short period of time and those with exaggerated stress induced cardiovascular response at young age have a high risk of blood pressure elevation in future. Objective To determine the cardiovascular reactivity in response to cold and to correlate its relation with factors such as smoking, family history and physical activity. Method Study was conducted in the Department of Pharmacy, Kathmandu University from July to November, 2015. Resting blood pressure was recorded using sphygmomanometer in sitting position after 5 minutes of rest. Out of 130 volunteers, 34 were found to be prehypertensive and equal number of normotensive were recruited randomly to perform the test. The subjects were directed to immerse his/her right hand up to the wrist in cold water of 10˚C for 1 minute. The blood pressure was recorded just before the hand was taken out of the water and then 1.5 minutes and 4 minutes after the withdrawal. Data was analyzed by Student's t test using Microsoft Excel 2007. Result Systolic and diastolic blood pressure increased significantly after cold pressor test in both normal (systolic blood pressure from 110±6.46 to 119±9.45 mmHg and diastolic blood pressure from 71±4.63 to 78±6.15 mmHg) and prehypertensive group (systolic blood pressure from 122±6.75 to 126±8.05 mmHg and diastolic blood pressure from 79±6.78 to 85±7.76 mmHg). Maximum recovery in both systolic and diastolic blood pressure was observed in 2.5 minutes of removal of hand from cold water. Though sharp drop was observed in blood pressure at the end of 2.5 minute in both groups of individuals, the recovery in case of prehypertensive individual was not sharper. In the present study, significant rise in diastolic blood pressure was observed in prehypertensive smoking males. Also the difference was significant (p<0.02) in recovery of diastolic blood pressure between smoker and non smoker prehypertensive group. Conclusion This study suggests that prolonged elevation in blood pressure in response to stress in young individual can be used as marker of development of hypertension in future. Adopting a healthier lifestyle can help to delay the development of hypertension in later life.