Hemodynamic responses to stress among black women: fitness and parental hypertension.

摘要

PURPOSE: We compared hemodynamic aspects of the relationship between cardiorespiratory fitness and blood pressure changes during and after laboratory stress in young black women with or without parental history of hypertension. METHODS: Participants were 30 normotensive, black American women having low to moderate fitness levels (i.e., VO2peak) assessed by cycle ergometry who performed standard active and passive coping laboratory stressors. Blood pressure, heart rate, stroke volume, cardiac output, total peripheral resistance (TPR), calf blood flow (CBF), and calf vascular resistance (CVR) were assessed during exposure to forehead and hand cold pressors, and mental arithmetic, as well as during recovery after the tasks. RESULTS: Fitness was positively related to increases in either TPR or CVR during each stressor. In contrast, fitness was positively related to blunted blood pressure during or after passive stress (i.e., hand or forehead cold) and enhanced recovery of blood pressure and TPR after the active stressor (i.e., mental arithmetic); effects of fitness on the vascular responses during and after mental arithmetic were stronger among women having a negative history of parental hypertension. CONCLUSION: The findings confirm our previous report that fitness blunts systolic blood pressure response during the hand cold pressor in young women. They also suggest that future studies of fitness and blood pressure reactivity during stress should focus on the regulation of vascular responses and their recovery after stress. Weaker effects of VO2peak after mental arithmetic in the positive history group indicate that the level of fitness required to modify recovery from mental stress among black American women may differ according to parental history of hypertension.