“Multiple clinical trials over the last 3 decades have documented that the effects on blood pressure (BP) and the safety profile of antihypertensive medications depend on the time of ingestion,” explains Ramón C. Hermida, PhD, FASH, FAHA. Limited evidence suggests that treatment at bedtime may be associated with reduced cardiovascular risk.
For a study published in the European Heart Journal, Dr. Hermida and colleagues sought to confirm whether ingestion time impacts cardiovascular risk. More than 19,000 patients with true hypertension determined by ambulatory BP monitoring (ABPM) were randomized to ingest their antihypertensive medications either upon awakening or at bedtime. During a median 6.3-year follow-up, participants were evaluated by 48-hour ABPM at least annually.
The researchers found that “the sleep time-relative SBP/DBP decline was significantly greater in those of the bedtime regimen; accordingly, the proportion of patients with the higher cardiovascular disease (CVD) risk non-dipper BP pattern was significantly lower with bedtime treatment than with upon-awakening treatment (37% vs. 50%),” explains Dr. Hermida. Additionally, bedtime ingestion reduced the risk of both fatal and non-fatal cardiovascular events when compared with ingestion upon awakening (HR, 0.55).
“The trial also documents that sleep-time BP is a highly significant marker of cardiovascular risk, independent of BP during activity being normal or elevated,” notes Dr. Hermida. “This calls for a new definition of true hypertension, as people with elevated BP at the physician’s office might or might not have high cardiovascular risk depending on how their BP might be while asleep. Proper management of hypertension would thus require diagnosis by ABPM (mainly in terms of elevated systolic BP during sleep) and treatment, preferably at bedtime.”
With the findings indicating that patients who take their BP-lowering medications at bedtime, compared with upon waking, experience improved ambulatory BP control while asleep as well as reduced CVD morbidity and mortality risks, Dr. Hermida suggests that further studies be conducted to observe other ethnic groups and corroborate benefits of prescribing BP-lowering medications for bedtime treatment.
Bedtime hypertension treatment improves cardiovascular risk reduction: the Hygia Chronotherapy Trial