This is an interesting initial evaluation of the effects of a daily low dose aspirin taken just before bedtime. Patients were randomized to receive aspirin at different times during the day. All of the patients had pre-hypertension, these are people with borderline high blood pressure readings not yet receiving blood pressure medications. Blood pressure measurements were evaluated with a 48 hour ambulatory blood pressure monitor, prior to starting daily aspirin usage and then 3 months after starting daily aspirin usage. Blood pressure measurements did not change in patients taking aspirin in the morning upon awakening. Seventy-one percent of the patients who took aspirin at bedtime experienced a reduction in their blood pressure readings. No changes in heart rate were observed in any of the patient groups over time. The researchers believe the aspirin when given at night may be decreasing the nocturnal renin peak and enhancing the production of nitric oxide. Both of these substances could facilitate blood pressure lowering.
This was a small study and a larger multicenter trial is being developed. But the take away message is – if you are taking a daily aspirin and have high blood pressure/hypertension or borderline high blood pressure readings it may be more beneficial to take the aspirin dose at bedtime. Definitely something to discuss with your healthcare provider or pharmacist.