Systemic hemodynamic determinants of blood pressure in women: age,
physical activity, and hormone replacement.
Hunt, Brian E., Kevin P. Davy, Pamela P. Jones, Christopher A.
Desouza, Rachael E. Van Pelt, Hirofumi Tanaka, and Douglas R. Seals.
Human Cardiovascular Research Laboratory, Department of
Kinesiology, University of Colorado, Boulder, CO 80309; and
Department of Medicine, Divisions of Cardiology and Geriatric
Medicine, University of Colorado Health Sciences Center, Denver, CO
80262
APStracts 4:0168H, 1997.
We tested the hypothesis that the age-related changes in systemic
hemodynamic determinants of arterial blood pressure in healthy women
are related to physical activity and hormone replacement status.
Sixty-six healthy normotensive premenopausal (21-35 yr) and
postmenopausal (50-72 yr) sedentary and endurance-trained women were
studied under supine resting conditions. Mean blood pressure was 7
mmHg higher in sedentary post- compared to premenopausal women, which
was associated with an 11 mmHg higher systolic blood pressure, a 25%
lower stroke volume and cardiac output, and a 50% higher systemic
vascular resistance (all p<0.05). Absolute (ml) levels of total
blood volume did not differ across age, but resting oxygen
consumption was 35% lower in the postmenopausal women (p<0.05). The
elevations in mean and systolic blood pressures across age were
similar in endurance-trained runners, but, in contrast to the
sedentary women, were not associated with significant age-related
differences in cardiac output, stroke volume, or oxygen consumption,
and only a modest (15%) increase in systemic vascular resistance
(p=0.06). Postmenopausal swimmers demonstrated the same systemic
hemodynamic profile as postmenopausal runners, indicating a non
-specific influence of the endurance-trained state. Blood pressure and
its systemic hemodynamic determinants did not differ in
postmenopausal users compared to non-users of hormone replacement
therapy. Resting oxygen consumption was the strongest physiological
correlate of cardiac output in the overall population (r=0.65,
p<0.001). We conclude: 1) the increases in arterial blood pressure
at rest with age in healthy normotensive women are not obviously
related to habitual physical activity status; 2) the systemic
hemodynamic determinants of the age-related elevations in blood
pressure are fundamentally different in sedentary vs active women,
possibly due, in part, to an absence of decline in resting oxygen
consumption in the latter; and 3) systemic hemodynamics at rest are
not different in healthy normotensive postmenopausal users vs non
-users of estrogen-based hormone replacement.
Received 20 December 1996; accepted in final form 31 March 1997.
APS Manuscript Number H1140-6.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 14 May 1997