Previous prospective studies have shown that sleep-time blood pressure (BP) is a better predictor of CVD risk than either a single daytime or a 24-hour BP measurement.
Dr Ramón Hermida (University of Vigo, Spain) said in an interview that his study was designed to test the hypothesis that taking at least one blood-pressure medication at bedtime would be more effective in reducing CVD risk than would conventional dosing, in which patients take all their BP medications in the morning. He added that having patients take their medications at bedtime is a cost-effective and simple strategy to achieve adequate asleep-BP reductions and to preserve or reestablish a normal 24-hour pattern, in which BP drops at night. Hermida and colleagues have previously reported full results of the MAPEC trial, showing that taking antihypertensive drugs at night-time can improve BP control in a heterogeneous group of people with hypertension .
Hermida et al's new analysis looked only at the 776 MAPEC men and women with resistant hypertension who were randomly assigned to take all their prescribed antihypertensive medications upon awakening or at least one of them at bedtime.
The bedtime group originally took all BP medications at night, but if they required additional medication during the study at the discretion of their physicians, they could take the additional medication at any time. None of the nighttime medications was allowed in the morning, meaning that any one drug could not be taken at both times. For controls, who took all medications in the morning, any additional BP medications had to be taken in the morning.
BP was measured at baseline at 20-minute intervals throughout waking hours and at 30-minute intervals at night. Periods of daytime activity and nocturnal sleep were determined using a wrist actigraph. Median follow-up was 5.4 years.