Abstract 11947: Effects of Nighttime Single-Dose Administration of Vasodilating vs. Sympatholytic Antihypertensives on Sleep Blood Pressure in Hypertensives With Sleep Apnea Syndrome - A Crossover Study -
Background: Obstructive sleep apnea syndrome (OSAS) is associated with nocturnal hypertension with higher sleep blood pressure (BP) and increased sleep BP variability, both of which increase the cardiovascular risk. We recently developed a trigger sleep BP monitoring (TSP) method based on the automated fixed-interval measurement function with an oxygen-triggered function that initiates BP measurement when oxygen desaturation falls below a variable hypoxia threshold continuously monitored by pulseoximetry.
Methods: In this crossover design study, we evaluated the effect of nighttime single-dose administration of vasodilating (nifedipine 40 mg) vs sympatholytic (carvedilol 20 mg) antihypertensives on sleep BP level and sleep BP surge using TSP in 11 hypertensive OSAS patients.
Results: The nighttime single-dose administration of both nifedipine and carvedilol markedly lowered the mean sleep systolic BP (SBP) (the average of SBPs measured every 30 min by a fixed-interval function)(-24.5 mmHg, -15.5 mmHg, both p≤0.001) and the hypoxia-peak sleep SBP (maximum SBP measured by oxygen-triggered function)(-26.7 mmHg, -21.7 mmHg, both p≤0.01). The BP-lowering effects of nifedipine on the mean sleep SBP (p≤0.05) and minimum sleep SBP (p≤0.01) were stronger than those of carvedilol, while that on the hypoxia-peak sleep SBP was comparable between the two drugs (figure). Sleep SBP surge (difference between the hypoxia-peak SBP and SBPs within 30 minutes before and after the peak SBP) was only significantly reduced by carvedilol (p≤0.05).
Conclusions: The nighttime dosing of both vasodilating and sympatholytic antihypertensive drugs is effective to reduce sleep BP but with different BP-lowering profiles, suggesting the potential suppression of BP surge-related cardiovascular events during sleep in OSAS hypertensive patients.
- © 2013 by American Heart Association, Inc.