Prevalence and persistency of orthostatic blood pressure fall in older patients with isolated systolic hypertension. Syst-Eur Investigators.

Postural hypotension in older people has been the subject of many studies, but there remains some doubt as to its true prevalence. This study investigated the prevalence and persistency of an exaggerated orthostatic blood pressure (BP) fall in a large group of older patients with isolated systolic hypertension. A total of 2716 patients, 917 men and 1799 women, whose age ranged from 60-100 years, were examined at three separate outpatient visits on a placebo in the single-blind run-in phase of the Syst-Eur Trial. The supine and standing BPs at each visit were the averages of two readings. An exaggerated BP fall was defined as a drop in systolic pressure by at least 20 mm Hg 2 min after assuming the standing from the supine position, or as a drop in the diastolic pressure by at least 10 mm Hg. The reproducibility of orthostatic BP changes was evaluated by the Bland and Altman technique. With the three run-in visits combined, the sitting pressure averaged ( +/- standard deviation) 174 +/- 11 mm Hg systolic and 86 +/- 6 mm Hg diastolic. Systolic pressure fell on average by 5 +/- 12 mm Hg from the supine to the standing position, whereas diastolic pressure increased by 2 +/- 7 mm Hg. The percentage of patients showing an exaggerated orthostatic BP fall was constant at each of the three run-in visits, ie 11-12% for systolic pressure and 4% for diastolic pressure. An exaggerated BP fall at each of the three run-in visits was only present in 3% of the patients for systolic pressure and in 0.4% for diastolic pressure. An exaggerated BP fall at the run-in visits was not associated with dizziness and syncope, which occurred in only 1% of the patients. The orthostatic fall in systolic, but not diastolic pressure, was greater (0.6 mm Hg; P < 0.05) at the second than at the first visit. The repeatability coefficients tended to be higher (60-65%), signifying lower reproducibility, than those for the BP levels (45-55%). An exaggerated fall in systolic or diastolic pressure may occasionally occur in nearly 10% of older patients with isolated systolic hypertension even without antihypertensive drug therapy, but a persistent orthostatic response in only rarely observed.