Asleep blood pressure could present a novel target for CVD risk

Taking one or more blood pressure (BP) drugs at bedtime reduced asleep blood pressure and cardiovascular disease risk compared to taking all hypertension drugs upon awakening, a new study found.

Spanish researchers prospectively studied a consecutive series of 3,344 adult patients. They had been recruited from those referred to the hospital for ambulatory blood pressure monitoring (ABPM) mainly to confirm hypertension or to evaluate control in already treated patients. Inclusion criteria required patients to be normotensive, untreated hypertensive, or resistant to treatment. Results were published online Aug. 29 by the Journal of the American College of Cardiology.

Hypertension in untreated patients was defined as awake mean BP over 135/85 mm Hg and/or an asleep mean BP over 120/70 mm Hg. By these criteria, 734 patients were normotensive and 2,610 were hypertensive (776 with resistant hypertension).

Patients with untreated hypertension were randomly assigned to take medication either upon awakening or at bedtime. Participants with resistant hypertension were randomized to either exchanging one of their medications with a new one while taking all medications in the morning or shifting one BP drug to bedtime.

During the median follow-up period of 5.6 years, there were 331 cardiovascular events. These occurred among patients who were predominantly male; were older; and at baseline were likely to have type 2 diabetes, obstructive sleep apnea, metabolic syndrome, and/or abdominal obesity. The patient's mean asleep BP was the most significant predictor of major cardiovascular disease (CVD) events, researchers reported. The reduced hazard ratio (HR) associated with each 5-mm Hg decrease in mean asleep systolic pressure during follow-up was significant for patients with normal (HR, 0.81; 95% CI, 0.68 to 0.95; P<0.005) or elevated BP (HR, 0.84; 95% CI, 0.79 to 0.89; P<0.001).

The researchers wrote, “All together, these results not only corroborate that the asleep BP mean is the most significant prognostic marker of CVD morbidity and mortality, as previously suggested, but also document for the first time that decreasing asleep BP mean significantly reduces CVD risk.”

An editorial noted that a strong case has been made to move at least some part of the antihypertensive regimen to bedtime as a default standard, but also cautioned that the safety of nighttime drug administration must be established. Nocturnal hypotension could result in cerebral and myocardial ischemia.

Still, the editorialists wrote, “The mere suggestion that CV event rates in patients with hypertension can be reduced by more than 50% with a zero-cost strategy of giving existing medications at bedtime rather than in the morning is nothing short of revolutionary.”