Timing is everything in aspirin therapy for prehypertension, according to a new study out of Spain. Patients who took low-dose aspirin right before bedtime reported much better responses than those who took the medicine in the morning.
“These results show we cannot underestimate the impact of the body’s circadian rhythms,” observes lead author Ramón C. Hermida, PhD, director of bioengineering and chronobiology at the University of Vigo in Spain.
The results of the study were presented at the American Society of Hypertension’s annual scientific meeting in May.
The 244 study participants consisted of 97 men and 138 women aged 30-56 years. All had been previously diagnosed with prehypertension (systolic BP between 120 and 139 mm Hg or diastolic BP between 80 and 89 mm Hg) on multiple readings and received counseling about improved diet and exercise.
They were then divided into two groups, one taking 100 mg aspirin on awakening, the other on retiring. A control group took no aspirin at all.
Three months later, the bedtime group saw their systolic BP decline by an average of 5.4 mm Hg and their diastolic BP decrease by an average of 3.4 mm Hg. The pattern held up whether readings were taken during active hours or nocturnally. BP showed no change among those taking aspirin in the morning or not at all.
“This is the first study to reveal that taking aspirin at bedtime as opposed to upon waking is an effective strategy to lower BP and a cost-effective way to individualize treatment in prehypertensive patients,” Dr. Hermida observes.