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Too little, too much sleep boosts heart-attack risk

November 19, 2019 | UCI Health
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Sleep researchers have been examining the connection between cardiovascular disease and too little or too much sleep for awhile.

A new study published in the Journal of the American College of Cardiology found that people who sleep less than six hours or more than nine hours a night have a 32% increased risk of experiencing a heart attack in their lifetimes.

“There’s been a lot of research linking short sleep — around six hours a night or less — with cardiovascular disease,” says UCI Health psychologist Ariel Neikrug, PhD, director of behavioral sleep services for UCI Health Sleep Medicine Services in Newport Beach.

“This new study found that risk of heart attack increases in people who routinely get below seven hours of sleep each night.”

The study also found that even people whose habitual sleep patterns extend to 10 hours or more are also at elevated risk for a heart attack.

How is sleep related to health?

The mechanisms for how too little or too much sleep raise the risk of heart attack and a host of other diseases, including stroke, high blood pressure, diabetes and obesity x— are not well understood.

But Neikrug cites two factors that are thought to play a role:

  • Blood pressure dipping: While people sleep, they experience a normal dip in blood pressure. With sleep loss, people don’t experience as much lowering of blood pressure. Some studies suggest that can increase risk of disease and mortality by 25%, he says.
  • Hormonal shifting: Sleep loss also can lead to difficulty in regulating hormones that increase or suppress appetite. Neikrug explains that sleep loss over even as few as two days can increase hunger and overeating, which can lead to obesity, a significant risk factor for cardiovascular disease.

Less well known understood is how too much sleep may also contribute to an elevated risk for heart attack.

“We know that there’s a U-shaped pattern of sleep and mortality,” Neikrug explains. “At the very low or very high end, you’re more likely to have a higher mortality rate.”

Understanding sleep patterns

A variety of factors can influence why we sleep too little or too much.

For example, we might sleep too little because the stress of our busy lives keeps us from falling and staying asleep. Pain also can make sleeping difficult. Illness may also be responsible for people getting too much sleep.

Then again, Neikrug notes, overall lifestyle may be a bigger factor than simply sleep.

People who spend too much time in bed aren’t likely to be working out, getting enough light exposure to keep circadian rhythms balanced, or eating healthy foods to maintain health.

So, how much sleep is best?

In many studies, researchers have shown that people who get between seven and eight hours of sleep a night tend to have the best health outcomes. So that’s the recommendation, although each individual is unique, Neikrug says.

There are times in everyone’s lives when they sleep too little or too much for reasons beyond their control.

A new baby will disrupt parents’ sleep cycles. People who worry about work, school, heath or finances may also have difficulty sleeping.

Making up for lost sleep

What about partying late or working too long during the week? Is it a problem to try to catch up on the weekends?

Yes, says Neikrug. “This phenomenon is called ‘social jetlag,’ as we shift our sleep by several hours every weekend to recover from the week. Such patterns may result in other issues. We recommend maintaining a stable sleep schedule with minimum shifts. Nonetheless, we can recover from the acute impacts of insufficient sleep.”

The increased risk for cardiovascular problems, however, results from long-term sleep patterns beginning as early as the teenage years.

“We’re talking about chronic sleep problems — you don’t become obese overnight or develop plaque in your veins or your brain overnight.”

When to seek help

But if you’re feeling run down when you wake up, lack energy during the day or fall asleep at inappropriate times, it’s time to seek help.

A good place to start is to talk with your primary care provider. If sleep problems persist, you may want to seek services at a sleep medicine center.

”At UCI Health, we have a multidisciplinary care team that includes experts in pulmonary medicine, psychiatry, neurology and psychology,” Neikrug says. “Based on the type of sleep complaint and clinical assessment, a patient may require additional testing and possibly an overnight sleep study.”

Establishing a healthy sleep regimen

In the meantime, if you are having trouble sleeping, here are some tips to building into a healthy daily routine:

  • Maintain a consistent wake-up time
  • Don’t take naps during the day
  • Expose yourself to bright light in the mornings
  • Reduce alcohol use before sleeping
  • Exercise regularly
  • Maintain a healthy diet

Recognizing the importance of good sleep

“I hope that as a society and as a culture, we start to prioritize sleep,” says Neikrug.

“Too often, I hear things like, ‘I’ll sleep when I’m dead.’ Well, the truth is that if you don’t sleep well, disease and death are more likely.”

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