Patients are being urged to take blood pressure drugs in the evening rather than the morning to cut their risk of an early death.
A new study published in the European Heart Journal found that people were far less likely to suffer – and die from – heart attacks, heart disease and stroke if they took their drugs to lower blood pressure at bedtime.
The research is the biggest study of its kind to investigate the idea that the timing of drugs affects health outcomes.
For the clinical trial, 19,084 people with high blood pressure were split into two groups, with the first taking their entire dose of blood pressure pills at bedtime, and the other group taking them after waking in the morning.
At least once a year, the groups had their blood pressure monitored for a period of 48 hours.
Over a follow-up period of just over six years, 1,752 patients died from cardiovascular disease, had a heart attack, suffered heart failure or stroke, or had a coronary revascularisation procedure (to unblock narrowed arteries).
Compared to those who took their pills in the morning, people who took them in the evening had a 66% lower risk of death from heart disease, a 44% reduced risk of heart attack, and a 40% lower risk of coronary revascularisation.
They also had a 42% lower risk of heart failure and almost half the risk of stroke.
The findings held true even when factors likely to influence the results were taken into account, such as cholesterol levels and gender, and whether people smoked or had Type 2 diabetes.
The research was led by a team from the University of Vigo in Spain.
Author Professor Ramon Hermida said: “Current guidelines on the treatment of hypertension do not mention or recommend any preferred treatment time.
“Morning ingestion has been the most common recommendation by physicians based on the misleading goal of reducing morning blood pressure levels.”
However, he said blood pressure levels when a person is asleep are a significant indicator of cardiovascular disease risk, and taking pills at night helps to lower blood pressure at this time.
Tim Chico, professor of cardiovascular medicine at the University of Sheffield, said the results of the study were “impressive”.
Given there was little risk in taking medication before bed, “there is enough evidence from this study to recommend that patients consider taking their medication at bedtime”, he said, adding that patients would want to speak to their doctor first.
Paul Leeson, professor of cardiovascular medicine at the University of Oxford, said: “This study has the potential to transform how we prescribe blood pressure medication. The scale of the project, length of follow up and size of effect are impressive.
“Importantly, this is a ‘real world’ study where doctors were allowed to prescribe whatever they wanted and just change medication timing.
“This means the findings are likely to be relevant to most people who take tablets for high blood pressure.”
Vanessa Smith, senior cardiac nurse at the British Heart Foundation (BHF), said the study supported previous evidence but further research was needed.
She added: “If you’re currently taking blood pressure medication, it’s important to check with your GP or pharmacist before changing the time you take it.
“There may be specific reasons why your doctor has prescribed medication in the morning or night.”