Aerobic exercise attenuates blood pressure reactivity to cold pressor test in normotensive, young adult African-American women

Abstract

Exaggerated blood pressure reactivity to behavioral stress has been observed in the African-American population, and such a pressor response is believed to play a role in hypertension. Regular aerobic exercise has been shown to exert an anti-hypertensive effect, and this may alter the blood pressure hyperreactivity observed in African Americans. To test the hypothesis that aerobic exercise attenuates pressor reactivity in African Americans, we studied eight healthy aerobically-trained normotensive African-American females and five similar sedentary females. The stress stimuli consisted of the cold pressor test with the foot immersed in ice water for two minutes. The aerobic exercise training protocol consisted of six weeks of jogging at 60-70% of peak oxygen uptake (VO2peak), three days/week for 35 min/exercise session. Systolic blood pressure, diastolic blood pressure, mean arterial blood pressure, heart rate, cardiac output, total peripheral resistance, and forearm blood flow were measured. Manifestation of a training effect was illustrated by a 24.1 +/- 0.2% increase in VO2peak (26.9 +/- 1.2 mL x kg(-1) min(-1) vs 35.4 +/- 1.6 mL x kg(-1) min(-1)) (P<.05). Within the exercise-trained group there was a 6.3 +/- .15% decrease in systolic pressure (129 +/- 4.6 mm Hg vs. 121 +/- 5.4 mm Hg) (P<.05), and a 5.0 +/- .05% decrement in mean arterial blood pressure (99 +/- 3.3 mm Hg vs 94 +/- 3.6 mm Hg) (P<.05) during the cold pressor test. Pressor reactivity to cold stress did not change in the untrained group. Measures of heart rate, cardiac output, total peripheral resistance, and forearm blood flow were unaltered during conditions of the cold pressor test. We conclude that aerobic exercise attenuates the blood pressure reactivity to behavioral stress in young, adult normotensive African-American females. A lifestyle change such as exercising may play a role in reducing the risk of hypertension in African-American women.