Blood pressure reactions to the cold pressor test and the prediction of future blood pressure status: data from the Caerphilly study.

The prognostic significance of the cold pressor test in hypertension remains a matter of controversy. Following determination at an initial screening session, blood pressure (BP) was recorded at baseline rest and in reaction to a cold pressor test. Follow-up screening BP was determined 5 years later. The effective sample was 1039 men, with an average age of 56.6 years at initial screening. Step-wise multiple regression indicated that BP reactions to the cold pressor test provided minimal independent prediction of follow-up BP over and above that afforded by BP at initial screening. In the case of follow-up systolic pressure, a model including only age and initial screening systolic BP (SBP) accounted for 38% of the variance; SBP reactions to the cold pressor did not enter the regression equation. In the case of follow-up diastolic BP (DBP), diastolic pressure at initial screening accounted for 21% of the variance, and while DBP reaction to the cold pressor test entered the equation, it accounted for only an additional 1% of the variance. These results suggest that the cold pressor test may be of limited clinical use in older populations.