Even a Minor Delay in Bedtime Linked to Higher Risk of High Blood Pressure

New research shows that even slight fluctuations in bedtime, as little as 34 minutes, may increase a person’s risk of high blood pressure, or hypertension. 

A study published in the journal Hypertension by the American Heart Association found that people with irregular sleep patterns were substantially more likely to experience high blood pressure.  

These sleep patterns included sleeping in on weekends or varying bedtime and waking times during the week. The study highlights the importance of maintaining a regular sleep schedule for optimal cardiovascular health. The increased risk of high blood pressure remained even when people got the recommended amount of sleep each night, aside from an irregular schedule.

Sleep Irregularities and High Blood Pressure

Though the link between poor quality sleep and issues such as hypertension, type 2 diabetes, and obesity is well documented, researchers wanted to investigate how sleep irregularities played a role. 

The study followed 12,287 adult participants from 20 different countries. The majority of the participants were male, middle-aged, and overweight. The researchers tracked their sleep duration and timing through a device under their mattresses and took 29 blood pressure readings for each person on average.

How Blood Pressure is Defined and Measured

The researchers defined high blood pressure as 140 mmHg over 90 mmHg or higher. They found that irregular sleep can be considered “a risk marker for poor cardiovascular health.” 

As variations in bedtime increased, so did a person’s risk of hypertension. Slight changes in bedtime, about 30 minutes, increased someone’s risk by about a third. Larger variations, such as 90 minutes, saw a 92% increased risk of hypertension.

Results of the study
Taking a more specific look, researchers found that an approximate 34-minute increase in sleep onset time irregularly was associated with a 32% increase in hypertension. Meanwhile, a 43-minute increase in sleep offset time, or waking up about 43 minutes later than normal, was associated with an 8.9% increase in hypertension. 

Those who slept too much or too little were between 20% and 30% more likely to have hypertension. 

Sleeping for a different number of hours each night also seemed to cause an issue. Those who varied their sleep duration by two hours or more had an 85% increased chance of having hypertension.

Although the study participants were primarily male, middle-aged, and overweight, there may be limitations on how applicable it is to the broader global population. 

People who are younger, women, or people who are not overweight may not see the same types of hypertension risks from irregular sleep habits.

The Link between Sleep Irregularities and High Blood Pressure

Researchers still don’t fully understand what mechanisms in the body link poor sleep to cardiovascular issues. During sleep, a person’s blood pressure usually goes down, which could explain why not sleeping enough or getting poor quality sleep could lead to hypertension. 

However, it’s still unclear as to why changing up your bedtime or sleep duration could produce a similar effect.

There are a few possible explanations for what could be going on. For one, sleep irregularities may actually be hard on the body. For example, sleep changes may cause an increase in nighttime stress or fight-or-flight response, which could raise blood pressure. 

Irregular sleep may also affect a person’s circadian rhythm. This could influence the body’s ability to regulate blood pressure or other bodily processes. 

Importance of Regular Sleep Schedule 

Regular and routine sleep is key to improving overall health and sleep efficiency. Individuals should try their best to pick a set time to go to sleep at night each day. 

Light therapy may help make this a bit easier, especially for people who have circadian rhythm disorders or otherwise have irregular sleep-wake hours. The therapy can help make people feel sleepy at night and awake in the morning on a more consistent schedule.

Another way to improve sleep is by creating a sleep-conducive environment. You can achieve this by creating a quiet, dark, and cool bedroom. Individuals should also avoid electronics before bed, as they can suppress melatonin levels and hinder the onset of sleep.

The Bottom Line

Even minor delays in bedtime may lead to an increased risk of hypertension, which can lead to serious health complications. It’s essential to prioritise sleep and maintain a consistent sleep schedule for optimal cardiovascular health. 

More research is needed to determine the relationship between sleep irregularities and hypertension for a broader range of people. The findings suggest that regular and routine sleep is essential for improving overall health and sleep efficiency. 

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