Taking Meds Before Bed May Improve Nocturnal Blood Pressure

Compared with morning dosing, taking once-daily antihypertensives at bedtime led to improved nighttime blood pressure measurements without increasing daytime measurements.

Type 2 diabetes patients who take their medicine for nocturnal hypertension before bed may have better blood pressure control than those who take their medicine in the morning, according to a study presented on September 26, 2013, at the European Association for the Study of Diabetes annual meeting in Barcelona.

Previous research indicates that high blood pressure at night may be a stronger independent risk factor for cardiovascular disease than daytime blood pressure. To investigate new strategies to treat increased nighttime blood pressure, researchers in the current study assessed whether bedtime dosing of once-daily antihypertensive medication reduced nighttime blood pressure without a subsequent increase in daytime blood pressure.

The open-label study enrolled 41 type 2 diabetes patients with a nighttime systolic blood pressure reading higher than 120 mm Hg, defined as nocturnal hypertension. Patients were instructed to take all of their once-daily antihypertensive drugs either in the morning or at night for the first 8 weeks, and then to switch to the opposite regimen for the next 8 weeks. Blood pressure measurements, measurements of arterial stiffness, and blood and urine testing were performed at baseline and after each 8-week period. Participants took an average of 3 once-daily antihypertensive drugs.

The results indicated that bedtime dosing was associated with a significant decrease in nighttime blood pressure. Average nighttime systolic blood pressure with morning dosing was 125.3 mm Hg, compared with 117.8 mm Hg with bedtime dosing—a 7.5—mm Hg difference. When patients took their medications at night, 24-hour systolic blood pressure was also significantly improved when compared with morning dosing (128.7 mm Hg vs. 131.7 mm Hg).

In addition, bedtime dosing did not lead to an increase in daytime systolic blood pressure. Average daytime systolic blood pressure for morning dosing was 134.2 mm Hg compared with 133.0 mm Hg for nighttime dosing. In addition, dosing time did not affect morning surge. Similar trends for nighttime and 24-hour decreases without morning increases were seen in diastolic blood pressure, mean arterial pressure, and pulse pressure when medications were taken at night. The results also associated bedtime dosing with increased nocturnal natriuresis.

These findings suggest that taking antihypertensive medications before bed may have significant benefits for both nocturnal and 24-hour blood pressure control, without increasing morning blood pressure.

“In patients with type 2 diabetes and nocturnal hypertension, dosing of antihypertensive drugs at bedtime may be favorable,” the authors conclude.