Influence of metoprolol and cilazapril on blood pressure and on sleep apnea activity

Up to 50% of hypertensive men are subject to sleep apnea (SA). With a prevalence in men of up to 10%, SA is a common illness and hypertension (HT) one of its early symptoms. It is important to have available a drug treatment that will effectively control blood pressure (BP) without exacerbating symptoms of SA. Twelve patients with SA and HT were investigated in a double-blind, comparative trial. Patients were randomly allocated to either metoprolol (M) 100 mg daily or cilazapril (C) 2.5 mg daily. Polysomnographic measurements under standardized conditions including intraarterial BP monitoring were taken on two consecutive nights each before and after the 1-week treatment. Values in the M group were (mean ± 95% CI) systolic BP 161 ± 2.1 vs. 148 ± 2.2 mm Hg (p < 0.01); diastolic BP 98 ± 1.8 vs. 93 ± 1.8 mm Hg (p < 0.01); and HR 73 ± 1.2 vs. 65 ± 1.1 beats/min (p < 0.01). Corresponding figures for the C group were systolic BP 140 ± 2.1 vs. 127 ± 2.1 mm Hg (p < 0.01); diastolic BP 95 ± 1.7 vs. 78 ± 1.7 mm Hg (p < 0.01); and HR 82 ± 1.1 vs. 79 ± 1.2 beats/min (p < 0.01). Whereas C reduced both BP and HR in all sleep phases, M produced no changes during REM sleep. SA activity was 45 (range 15-91) vs. 34 (range 2-57) apneas per hour of sleep in the M group and 54 (range 21-84) vs. 40 (range 8-72) apneas per hour in the C group (p < 0.01). There were no changes in total sleep time or in the proportions of non-REM to REM sleep. Both M and C reduce nocturnal BP in SA patients, but the effect of C is seen in all sleep phases. C has a more favorable effect on the disturbed nocturnal blood pressure of SA patients.