In France, approximately one in three adults lives with a
high blood pressurea major factor in stroke and heart attack. Despite medication, a low-salt diet and stopping smoking, many people still have high blood pressure. In this context, “fewer than one in four hypertensives have properly controlled blood pressure“, recalled Health Insurance.
A team from the Oregon Institute of Occupational Health Sciences, in the United States, therefore wondered if a simple everyday gesture could help: go to bed at a fixed time. Researchers Saurabh Thosar and Leandro Campos de Brito followed 11 hypertensive adults for three weeks and report “surprising results” that prompted them to publish in the journal
SLEEP Advances.
Going to bed at a fixed time: what the study on hypertension shows
The participants, aged 45 to 62, had a
blood pressure between 130/80 and 160/100 mmHg or were already taking antihypertensive treatment. After a week of observing their usual sleep, the team asked them to choose a bedtime and stick to it for two weeks, without naps during the day and without specific instructions on the duration of sleep.
Using activity monitors and sleep diaries, the researchers showed that bedtime variability went from around 30 minutes to just 7 minutes, while sleep duration remained stable around 8.3 hours. For them, “The results were striking” and blood pressure “reduced significantly”, with “reductions comparable to those achieved by regular exercise or salt reduction“. In a press release, they speak of “A reduction of 4 mmHg (millimeters of mercury) for systolic and 3 mmHg for diastolic over 24 hours, and up to 5 mmHg/4 mmHg overnight“, judged declines”clinically significant“.
Regular sleep, circadian rhythm and nighttime tension
Ambulatory measurements over 24 hours confirmed that the effect of regular bedtime is concentrated at night: nocturnal systolic pressure fell by approximately 5 mmHg and diastolic by 4 mmHg, while during the day only diastolic decreased slightly. “Nighttime blood pressure showed even greater drops“and, even if”These numbers may seem modest, but a 5 mmHg drop in nighttime blood pressure can reduce the risk of cardiovascular events by more than 10%.“, recall the authors. Half of the eleven volunteers exceeded a threshold of change considered physiologically positive.
To explain these effects, scientists point out that “sleep irregularity is associated with elevated blood pressure” in large population studies. International research has shown that a bedtime that varies by 30 minutes from one evening to the next increases the risk of hypertension by more than 30%. The authors “suspect” that varying bedtimes disrupt the
circadian rhythmthis internal clock which “regulates both sleep-wake cycles and cardiovascular function“. By going back to bed each evening at the same time, the body would more easily return to a blood pressure profile which normally drops during the night.
A simple gesture, but only complementary therapy
However, this study remains an indicator because it was conducted on a very small sample, without a control group and over only two weeks. The authors emphasize that regularizing bedtime “can therefore be considered as a complementary therapy” and not of course as a single treatment for hypertension. No participant stopped their medications in the protocol, and the researchers insist on the fact that adjustment of treatments must always be done with a doctor.
For those who wish to be inspired, the instructions given to the volunteers were very simple. They had to choose a realistic bedtime, stick to it every night, and avoid naps. In practice, this can translate into a few daily benchmarks:
- Set a bedtime close to the one you already have, rather than too ambitious;
- Keep the same time slot all week, including weekends as much as possible;
- Plan a calm ritual before bed to help you fall asleep.
For the Saurabh Thosar team, “Going to bed at the same time is a low-cost, low-risk intervention that could effectively complement current treatments for hypertension“. Enough to add a new simple habit to the classic arsenal against high blood pressure.