Blood Pressure Response to Cold Stress in Black Cameroonian Adults

Abstract

Introduction: The cold test is known as a predictor of essential hypertension. The hemodynamic response to this test has rarely been studied in black African adults. Black Africans also suffer cold stress. But whether they suffer it the same way as other populations is still to be determined. Equipment and Method: We studied the response of blood pressure (BP) during the cold test in 62 black normotensive adults and hypertensive Cameroonians aged between 21 and 59 years. Those with an increase in systolic blood pressure (SBP) > 20 mmHg and/or diastolic blood pressure > 15 mmHg were considered to be hyper-reactors. Results: SBP increased significantly in hyper-reactors compared with normo-reactors in both hypertensive and normotensive subjects (176 ± 20 vs. 154 ± 11, p = 0.01 and 148 ± 17 vs. 125 ± 11, p < 0.001, respectively) and this increment persisted up to two minutes after the end of the stress exposure although the difference was no more statistically significant. We found the same result for the DBP (111 ± 13 vs. 99 ± 10, p = 0.04 and 95 ± 11 vs. 81 ± 10, p = 0.001, respectively). However, the DBP stayed higher in hyper reactors compared to normal reactors in the normotensive group up to four minutes after cessation of the stress exposure. The recovery time of the baseline BP was considerably longer in hyper reactors compared with the normal reactors (2.1 ± 0.9 vs. 1.1 ± 0.4 minutes, p = 0.01 and 1.9 ± 1.0 vs. 1.3 ± 0.5 minutes, p = 0.03 respectively in hypertensive and normotensive). Conclusion: Hyper reactors in the cold test have a more pronounced and prolonged reactivity. They are thus predisposed to develop hypertension.