Sleep deprivation increases risk for heart disease, studies show

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• A trio of new studies show that too little or too
  much sleep is
  associated with an increased risk for cardiovascular
  disease.
• Sleeping less
  than five hours per night raises the risk for a heart
  attack or stroke by about the same degree as smoking does,
  according one study in older men.
• This adds to a significant body of evidence that
  suggests
  regular sleep is essential for health.

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Most of us know that not getting enough sleep is bad for
us.

Yet many people believe their busy lives require that they skimp
on sleep. As Elon Musk recently
posted on Twitter at 2:30 a.m. (after being criticized
by Ariana Huffington for working so many hours and sleeping so
few), “I just got home from the factory. You think this is an
option. It is not.”

But the lengthy list of
negative ways that lack of sleep affects your body and brain
continues to grow. According to several new studies presented
Sunday at a meeting of the European Study of Cardiology, getting
too little — or too much — sleep is associated with significant
increased risk for cardiovascular problems including hardened
arteries, heart attacks, strokes, heart failure, and more.

“We spend one-third of our lives sleeping yet we know little
about the impact of this biological need on the cardiovascular
system,” Dr. Epameinondas Fountas, one of the authors of a
meta-analysis about the best amount of sleep for heart health,

said in a news release.

Fountas’ team looked at 11 studies with more than 1 million
participants, and their findings shed more light on the impacts
of sleep deprivation. The results give us even more reasons to
try to fit enough sleep into our lives.

Etienne Oliveau/Getty Images

What happens if you don’t get enough sleep

Although individual needs may vary, sleep researchers generally
say people should get
seven to nine hours of shut-eye per night. That’s considered
the amount
that’s optimal for good cognitive performance, safety, and
brain health, and for lower risk of cancer and death.

When it comes to cardiac disease, the authors of the
meta-analysis found that the sweet spot for lowest risk was six
to eight hours of sleep per night. Averaging less than that
was associated with an 11% increased risk for dying from coronary
heart disease or stroke at some point in the follow-up period of
approximately 9.3 years, and getting more than that was
associated with a 33% increase in risk.

Another
study on sleep, conducted by a different team of
scientists, was also presented at the European Society of
Cardiology conference. Those researchers had people wear a
waist-band monitor for one week to track their sleep patterns.
The results suggested that people who got less than six hours of
sleep per night or woke up frequently had about 27% more atherosclerosis:
hardening in the arteries that can lead to blockage or narrowing
and contribute to heart failure, stroke, or aneurysm.

Yet
another new study presented at the cardiology conference
reported on a group of 798 men from Gothenburg, Sweden, who
provided information on how long they slept in a 1993 survey,
when all participants were 50 years old. Twenty years later, the
men who had said they slept less than five hours per
night were found to have double the risk of a serious
cardiovascular event. That increased risk for a heart attack or
stroke is comparable to the effects of smoking or having
diabetes.

Andrew
Burton/Reuters

Good reasons to get regular sleep

All of these new studies show an association, not a
cause-and-effect relationship.

Pinpointing exact causal mechanisms is difficult, since a lack of
sleep messes with our bodies in a number of ways that increase
disease risk. One recent
study, for example, found that not getting enough sleep
changes genes in ways that promote obesity and impair metabolism.
Other research has shown that sleep deprivation
leads to inflammation, which may contribute to cardiovascular
disease risk.

“More research is needed to clarify exactly why, but we do know
that sleep influences biological processes like glucose
metabolism, blood pressure, and inflammation — all of which have
an impact on cardiovascular disease,” Fountas said.

Overall, the new research gives us even more good reasons to make
sure we sleep enough (but not too much) on a regular basis.

“Having the odd short night or lie-in is unlikely to be
detrimental to health, but evidence is accumulating that
prolonged nightly sleep deprivation or excessive sleeping should
be avoided,” Fountas said.