Do elderly males have superior blood pressure control to younger males during acute orthostatic stress?
T. Gabbett*, S. Weston & R. Barrett School of Physiotherapy and Exercise Science, Griffith University Gold Coast, Australia Due to the reduction in central venous pressure, stroke volume and cardiac output, a reduction in blood pressure is the typical immediate response to the upright, stationary posture (orthostasis). It has been documented that the reduction in blood pressure during orthostasis is greater in the elderly. However, it has recently been demonstrated that over 50% of healthy elderly males increase blood pressure in response to acute orthostatic stress (Gabbett et al., 1998). The purpose of this study was to investigate the immediate cardiovascular and sympathoadrenal responses of healthy young and older males during acute orthostatic stress. Following a 30-minute period of supine rest, eighteen young (20-30 yr) and fifteen older (70-75 yr) males were rapidly tilted to the upright, stationary position (90 head-up tilt [HUT]). Beat-by-beat recordings of heart rate (HR), me
