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Maintaining a consistent bedtime can significantly lower a person’s blood pressure for the entire day, according to a new study.
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Participants in the small proof-of-concept study experienced clinically significant average blood pressure reductions after just 2 weeks of going to sleep at the same time each night.
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The cardiovascular system, and blood pressure, are tightly tied to one’s sleep/wake cycle and internal clock. As a result, consistent sleep habits result in less disruption for the system to accommodate.
Simply going to bed at a regular time can lower a person’s 24-hour blood pressure, according to a new study from researchers at the Oregon Institute of Occupational Health Sciences.
This single, simple intervention can result in a clinically significant improvement in one’s blood pressure.
After 2 weeks of going to bed at a consistent time of their own choosing, study participants experienced an average 4 millimeters of mercury (mmHg) systolic and 3 mmHg diastolic reduction in 24-hour blood pressure.
The improvement was roughly the equivalent of reducing dietary sodium or participating in an exercise program. A reduction of 5 mmHg in nighttime blood pressure is associated with a 10% reduction in the risk of a cardiovascular event, and half of the participants met this threshold.
Sleep is considered an important factor in cardiovascular functioning, and other sleep-related behaviors are also known to deliver health benefits.
These include getting enough sleep, and getting good quality sleep, which can be easier to attain by sleeping in light-free environments.
The small, proof-of-concept study involved 11 participants, some of whom were on medication for high blood pressure, or hypertension. After a week of sleep monitoring, they were all asked to retire at a consistent time of their choice each night for two weeks.
The study is published in Sleep Advances.
Blood pressure and the circadian rhythm: What’s the link?
Blood pressure, changes throughout the 24-hour day, tightly tied to one’s circadian rhythm. As a result, blood pressure will be “dipping overnight, rising in the morning, [and] plateauing during the day,” said Jayne Morgan, MD, cardiologist and Vice President of Medical Affairs for Hello Heart, who was not involved in this study.
Cheng-Han Chen, MD, interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, CA, likewise not involved in the study, explained:
“Many aspects of your cardiovascular function, including blood pressure, are governed by your body’s internal circadian clock. Much of it is due to your body’s natural fluctuations in cortisol and adrenaline. These natural fluctuations are important for your body to function properly.”
When one’s circadian rhythm, which regulates a person’s sleep/wake cycle, is disrupted, the timing of the cardiovascular system also goes awry.
“It can’t adapt quickly,” said Chen, “because these rhythms are set […] They take days to adjust.”
As a result, “Poorer sleep quality [leads to] higher blood pressure. It’s as simple as that,” according to Morgan.
How sleep influences blood pressure
“An irregular bedtime,” Morgan told us, “can meaningfully disrupt the body’s ability to maintain a steady, healthy blood pressure, and the effect is stronger than many people realize — especially in midlife and for women in peri- and post-menopause.”
An ever-changing bedtime makes it harder for the brain’s master clock to synchronize with one’s sleep/wake cycle.
“This could lead to the blood pressure not dipping properly in the evening, and/or exaggerated morning surges of blood pressure, increasing your risk of stroke and other cardiovascular events,” cautioned Morgan.
Previous research has identified numerous issues arising for people with irregular bedtimes, she said. These include “shorter sleep duration, more fragmented sleep, less deep/slow-wave sleep (critical for cardiovascular repair).” Each of these factors can individually increase 24-hour blood pressure.
“Further,” Morgan noted, “there are metabolic and hormonal disruptions including cortisol dysregulation, worsened insulin sensitivity, and an increased RAAS (renin-angiotensin-aldosterone system). All worsen cardiometabolic risk and increase inflammatory markers.”
Irregular sleep activates ‘fight or flight’ response
One of the study’s interesting findings is that participants’ blood pressure began dropping ahead of predictable bedtimes as the study progressed.
“When the body can expect or the body has been exposed to a more regular pattern, then it can start anticipating and get ready for a normal cycle,” suggested Chen.
Morgan attributed the change to decreased sympathetic nervous system activity, saying that “irregular sleep patterns activate ‘fight or flight’ physiology.”
“Regular sleep,” she explained, “helps to reduce overnight epinephrine and norepinephrine levels as well as vagal tone, leading to reduced heart rates and vascular resistance. This drives sustained lower nighttime and early-morning blood pressure.”
Bedtimes: A simple, modifiable measure for heart health
“It’s great to see how something as simple as just telling people to go to sleep on time consistently makes such a big difference,” Chen told us. “That’s a relatively simple thing that can really help your health, rather than telling someone to take a medicine or go through a procedure.”
Morgan underscored that, in general, “irregular sleep is a modifiable driver of hypertension.“
“This is particularly powerful for post-menopausal women, where autonomic and RAAS changes amplify blood pressure sensitivity,“ she added.
Morgan also offered some tips on how to optimize sleep for overall cardiovascular health. She advised
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keeping your bedtime within a 60-minute window nightly
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aiming for 7–9 hours of sleep consistently
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accessing morning light exposure to anchor your circadian rhythm
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reducing evening stimulants and irregular shift-like behavior, such as screen time, late heavy meals, and late vigorous workouts.
View the original article on Medical News Today