Nocturnal decline in blood pressure: Reproducibility and effect of three beta-adrenoblockers

Effects of placebo, bisoprolol (10 mg q.d.), propranolol (80 mg b.i.d) and metoprolol (100 mg b.i.d) on nocturnal decline in blood pressure were evaluated by 24-hour blood pressure monitoring in 14 inpatients with mild-to-moderate hypertension in a double blind crossover study. Compared with placebo propranolol and bisoprolol produced significantly greater declines in nocturnal diastolic blood pressure (8,9+/-0,6, 12,9+/-1,3 and 12,6+/-1,4%, respectively). Propranolol caused greater than placebo decline in nocturnal systolic blood pressure (12,0+/-1,2 and 8,0+/-0,6%, respectively). Metoprolol did not affect these parameters. Average nocturnal blood pressure declines on placebo were equal during 5 periods of monitoring. However pronounced spontaneous fluctuations of individual values were noted. Thus in studies of nocturnal blood pressure decline it is advisable to conduct repetitive 24-hour blood pressure recordings both prior to and on treatment. Otherwise the attitude to results should be cautious.