Background Orthostatic hypotension is a common phenomenon in the elderly. H
ormonal changes during orthostatic stress have been described in elderly no
rmotensive people and in those with essential hypertension. However, the ho
rmonal response in elderly people who have systolic hypertension during ort
hostasis has not yet been quantified.
Methods In this study we investigated 14 non-diabetic men, aged 60 to 75 ye
ars, with untreated systolic hypertension who were subjected to 45 degrees
passive head-up incline on a tilt table for 15 min. Their hormonal profile
and hemodynamic changes were analyzed before and after the stress,
Results In the supine position, plasma levels of norepinephrine, atrial nat
riuretic peptide and aldosterone were in the normal range, while the plasma
renin activity was low. Immediately upon tilt the systolic blood pressure
fell but it reverted to baseline values after 15 min of orthostasis, At tha
t time the cardiac output decreased while the systemic Vascular resistance
and the plasma norepinephrine concentration rose. The atrial natriuretic pe
ptide appeared to fall, and the renin-aldosterone level did not change.
Conclusion The physiologic response to orthostatic stress in elderly people
with systolic hypertension is comparable to that of elderly normotensive p
eople and those with essential hypertension, i.e. a decrease in cardiac out
put and an increase in plasma norepinephrine levels. The atrial natriuretic
peptide appeared to fall appropriately. The response of the renin-aldoster
one system mimicked that in elderly patients with low renin essential isola
ted hypertension. These observations may have a bearing on the management o
f elderly people with systolic hypertension who also have orthostatic sympt
oms; they may not require a different approach from that needed for others
of the same age group. Coronary Artery Dis 9:597-601 (C) 1998 Lippincott Wi
lliams & Wilkins.