[Circadian rhythm of blood pressure in hypertension treated with enalapril and other drugs].

Twenty-four-hour "ambulatory blood pressure monitoring" (ABPM) was performed during the day at every 30 min and during the night at every 60 min in 38 persons admitted to the hospital. The subjects were divided into four groups: Group 1. healthy subjects (11); Group 2. essential hypertensive patients (7) before and during enalapril treatment; Group 3. patients with essential hypertension (10) treated with different antihypertensive drugs and Group 4. renal patients treated as in Group 3. Normal circadian rhythm was found in the healthy subjects and in the patients with essential hypertension, but no rhythm could be demonstrated in the renal patients. The high blood pressure decreased in response to enalapril in 7 patients without any decrease in the circadian rhythm. It was concluded that antihypertensive therapy does not abolish the circadian rhythm if there is any--and does not restore if it is lacking. The chances of the diagnostic use of circadian blood pressure rhythm are not impaired by the antihypertensive treatment.