AMBULATORY PRESSURE DECREASES ON LONG-TERM PLACEBO-TREATMENT IN OLDERPATIENTS WITH ISOLATED SYSTOLIC HYPERTENSION

Objective: This long-term study investigated the widely accepted hypot hesis that ambulatory pressure does not decrease in patients given pla cebo. Methods: One hundred and twelve older (greater than or equal to 60 years) outpatients with isolated systolic hypertension were recruit ed. Treatment consisted of a placebo during a 3-month baseline period and long-term follow-up. Results: At baseline, on placebo treatment, c linic systolic/diastolic (SBP/DBP) blood pressure (+/-SD) averaged 176 +/-12/86+/-7mmHg and 24-h SBP/DBP 151+/-15/81+/-10 mmHg. These pressur es were unaltered in 51 patients in whom the baseline measurements wer e repeated after a further month on placebo. After the 112 patients ha d received placebo for 1 year (median), clinic SBP/DBP fell by 6.6+/-1 5.9 (P<0.007)/1.4+/-7.4 (P=0.06) mmHg and 24-h SBP by 2.4+/-10.7 mmHg (P<0.05), whereas 24-h DBP did not change significantly The 24-h SBP d ecreased more with higher baseline level and longer follow-up (5-21 mo nths). Conclusions: These findings in older patients with isolated sys tolic hypertension suggest that in long-term studies the ambulatory pr essure may slightly but significantly decrease on a placebo. Like thos e using conventional sphygmomanometry, long-term studies using non-inv asive ambulatory monitoring require a placebo-controlled design.