Blood pressure responses to whole-body cold exposure : effect of carvedilol

The aim of this study was to test the effects of carvedilol on blood pressure (BP) and heart rate (HR) during whole-body cold exposure in hypertensive and normotensive subjects. Ten hypertensive and twelve normotensive subjects were exposed to cold (-15 degrees C, wind 3.5 m/s) three times for 15 min with a 1-week interval between the exposures. The study design was made according to a randomised double-blind, crossover method. Before the cold exposures the subjects ingested carvedilol or placebo once a day (carvedilol 12.5 mg/day for 2 days and then 25 mg/day for 5 days) for 1 week. The systolic (SBP) and diastolic (DBP) blood pressure and HR were measured every 3 min during the test procedures using an indirect ambulatory blood pressure monitor device (ABPM-02, Meditech Co.). In the hypertensive group, the cold exposure increased SBP/DBP from 119/75 mmHg to 143/96 mmHg during carvedilol treatment (P