Maximal aerobic power in essential hypertension.
Fifty untreated male patients aged 32 +/- 10 (s.d.) years, referred for hypertension, in whom organ damage was limited to WHO stages I and II, without underlying disease, performed a graded, uninterrupted exercise on a bicycle ergometer up to exhaustion. Mean brachial intra-arterial pressure at rest ranged from 74 to 152 mmHg. Maximal voluntary oxygen uptake was independently and negatively related to resting blood pressure (P less than 0.05), age (P = 0.05), and positively to body weight (P less than 0.05). Pulmonary wedge pressure and the components of the Fick equation--heart rate, stroke volume and arteriovenous oxygen difference--were measured in order to study the mechanisms involved. Stroke volume at peak exercise was inversely (P less than 0.05), and pulmonary wedge pressure positively (P less than 0.01), related to mean brachial artery pressure at rest. Peak heart rate was not significantly related to the severity of hypertension, but was inversely related to age (P less than 0.01). Stroke volume and pulmonary wedge pressure at the end of exercise were both similar in older and younger patients. Arteriovenous oxygen difference at peak exercise was not related either to blood pressure or to age. In conclusion, both high blood pressure and age reduce maximal voluntary oxygen uptake independently of each other by separate mechanisms; the former by an impairment of cardiac function, the latter by the limitation of peak heart rate.
Fagard
R
R
Department of Pathophysiology, Faculty of Medicine, University of Leuven, Belgium.
Staessen
J
J
Amery
A
A
D000328:Adult; D000375:Aging; D001794:Blood Pressure; D015444:Exercise; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D010101:Oxygen Consumption