October 23, 2019

expert reaction to study looking at the time of day when blood pressure medication is taken and cardiovascular disease risk

A study, published in European Heart Journal, reports that taking blood pressure medication before bed may be more beneficial than when taken in the morning. 

Dr Richard Francis, Head of Research, Stroke Association said:

“We’re pleased to see this research, which could potentially change the way we prevent strokes in the future. This is a robust study that shows that people who take their blood pressure medication at night have better blood pressure control and have reduced risk of a cardiovascular event such as a stroke or heart attack. Hopefully we can see studies like this recreated in the UK and combined with existing evidence, this could lead to a review of current guidelines on treating high blood pressure.”

Prof Tim Chico, Professor of Cardiovascular Medicine and Honorary Consultant Cardiologist, University of Sheffield, said:

“This important study tests whether the simple act of taking once daily blood pressure tablets at bedtime gives better protection against heart problems than if the same medications are taken in the morning.

“The results are impressive. From the 19,084 people who took part and were randomised to taking their tablets at either bedtime or morning, just over 9% suffered a heart problem over the 6.4 years of the study. Of these (by my calculations) around 1131 patients were taking their tablets in the morning but only around 623 patients taking their tablets at bedtime suffered the same problems.

“This study provides good evidence that it may well be better to take blood pressure tablets at bedtime, not in the morning. It is important to note that further studies would be needed to confirm how definite the benefits of taking medication at bedtime are. However, as taking medications at bedtime poses little risk there is enough evidence from this study to recommend that patients consider taking their medication at bedtime. Any such changes should be discussed with their doctor of course, and it is important to understand that this may not apply to medications that need to be taken more than once a day, or for blood pressure medications that are being prescribed for other problems such as angina or heart failure.”

Prof Paul Leeson, Professor of Cardiovascular Medicine, 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.

“Where the benefit comes from remains unclear. Does this improve patterns of sleep? Are side effects less problematic at night? Does blood pressure overnight better reflect heart health? Similar big studies looking at blood pressure medication timing are due to report soon and these will be important to confirm the findings as well as provide insights into why this matters.”

Prof Stephen MacMahon, Principal Director, The George Institute for Global Health, said:

“This is a surprising result. The findings suggest that compared with taking blood pressure lowering drugs in the morning, taking treatment at night halves the risk of a heart attack, stroke and death from cardiovascular disease. These effects are larger than the long-established effects of taking any blood pressure lowering treatment whatsoever, which is difficult to reconcile. Additionally, the size of the blood pressure reduction in the group that took treatment at night was only modestly greater than the reduction in the group that took their treatment in the morning, which makes the findings all the more unexpected. Results from a large ongoing British study addressing the same question will provide important additional evidence.”

‘Bedtime hypertension treatment improves cardiovascular risk reduction: the Hygia Chronotherapy Trial’ by Hermida et al. was published in European Heart Journal at 00:05 UK time on Wednesday 23 October. 

DOI: 10.1093/eurheartj/ehz754

Declared interests

Dr Richard Francis: None

Prof Tim Chico: None.

Prof Paul Leeson: None relevant to this paper.

Prof Stephen MacMahon: No conflicts of interest.