Hormonal response to orthostasis in elderly people with systemic systolic hypertension

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.