Night Time Aspirin Regimen Found to Reduce Blood Pressure

Patients with mild hypertension experienced a significant reduction in blood pressure as the result of regularly taking aspirin before bed, according to a new study.
To investigate the effect of aspirin taken at different times of the rest-activity cycle, Ramon C. Hermida, Ph.D., of Bioengineering and Chronobiology Laboratories, University of Vigo, Campus Universitario, Spain, and colleagues studied a group of 100 volunteers with untreated mild essential hypertension.
Study participants included 34 men and 66 women, ages 23 to 79 years. The entire group received nonpharmacological hygienic-dietary recommendations, including regular aerobic exercise, restrictions on sodium and alcohol consumption, and information on the Dietary Approach to Stop Hypertension Diet.

Researchers randomly assigned participants to 3 subgroups, which received a regimen of no aspirin, 100 mg aspirin after waking, or 100 mg aspirin before sleeping. Evaluation by blood pressure monitoring occurred for 48 consecutive hours for all participants at baseline and after completion of three-months of their prescribed regimen. Each participant received an ambulatory monitoring device during the monitoring periods. Automatic measurements for systolic blood pressure, mean arterial blood pressure, diastolic blood pressure, and heart rate occurred every 20 minutes between 7:00 a.m. and 11:00 p.m., and every 30 minutes at night.

No significant differences existed between subgroups for blood pressure or heart rate at baseline. However, researchers noted highly significant changes to blood pressure between groups after the 3-month treatment period. The subgroup following a regimen of evening aspirin administration showed a reduction in the 24 hour mean of 6.2 mm Hg in systolic blood pressure and 4.1 mm Hg in diastolic blood pressure. While 85% of this subgroup experienced a reduction of blood pressure, the effect was not evident for the subgroups receiving no aspirin or morning administration.

In addition, results indicate that administration of aspirin prior to rest may be valuable therapy for patients unable or unwilling to exercise or adhere to dietary restrictions. All subgroups reported poor compliance to nonpharmacological hygienic-dietary recommendations.