ASH: Bedtime Aspirin Has Antihypertensive Effects

Timing of aspirin administration important

THURSDAY, May 15 (HealthDay News) -- Among individuals with prehypertension, taking an aspirin at bedtime results in significant lowering of blood pressure, but the antihypertensive effect is not seen if the aspirin is taken in the morning, according to research presented at the American Society of Hypertension's 23rd Annual Scientific Meeting held May 14-17 in New Orleans.

Ramon C. Hermida, Ph.D., of the University of Vigo in Vigo, Spain, divided 244 individuals with prehypertension (systolic blood pressure of 120-139 or diastolic blood pressure of 80-89) into three groups, including one that took a 100-mg aspirin tablet on awakening and received lifestyle modification instructions, another group that took the aspirin at bedtime and received lifestyle modification instructions, and a third group that received only lifestyle modification instructions. Blood pressure levels were monitored at regular intervals for 48 hours at baseline and after three months of treatment.

Individuals who took the aspirin at bedtime had a mean decrease of 5.4 mm Hg of systolic blood pressure and 3.4 mm Hg of diastolic blood pressure, the researchers report. This blood pressure reduction was consistent during both active hours and during sleeping. Neither individuals who took a morning aspirin nor those in the lifestyle modification-only group had a reduction in ambulatory blood pressure.

"These results show us that we cannot underestimate the impact of the body's circadian rhythms," commented Hermida. "The beneficial effects of time-dependent administration of aspirin have, until now, been largely unknown in people with prehypertension."

Abstract #163
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