In a new study, researchers found that even if you are a non-smoker who exercises and has no genetic risk to heart disease, skimping on sleep—or getting too much of it—can increase your risk of a heart attack.
They also found that for those at high genetic risk for heart attack, sleeping between six and nine hours nightly can offset that risk.
The research was done by a team at CU Boulder and elsewhere.
Previous research has long suggested an association between sleep and heart health, but because those studies were observational—looking at different groups to see who develops the disease—it’s been difficult to determine whether poor sleep causes heart problems or vice-versa.
Many factors can influence both heart health and sleep, making it even more difficult to determine cause and effect.
The team analyzed the genetic information, self-reported sleep habits and medical records of 461,000 UK Biobank participants age 40 to 69 who had never had a heart attack, then followed them for seven years.
Compared to those who slept six to nine hours per night, those who slept fewer than six hours were 20% more likely to have a heart attack during the study period.
Those who slept more than nine hours were 34% more likely.
For instance, people who slept five hours per night had a 52%higher risk of heart attack than those who slept seven to eight hours, while those who slept 10 hours nightly were twice as likely to have one.
When the researchers looked only at people with a genetic predisposition to heart disease, they found that sleeping between six and nine hours nightly cut their risk of having a heart attack by 18%.
The team says sleeping too little can impact the lining of the arteries, or endothelium, impact bone marrow development of inflammatory cells but also lead to poor dietary choices and ill-timed eating (which can in turn impact weight and, thus, heart health).
Sleeping too much may also boost inflammation in the body, which is also linked to heart disease.
This study provides some of the strongest proof yet that sleep duration is a key factor when it comes to heart health, and this holds true for everyone.
Regardless of what people’s inherited risk for a heart attack is, sleeping a healthy amount may cut that risk just like eating a healthy diet, not smoking, and other lifestyle approaches can.
One author of the study is Celine Vetter, an assistant professor of Integrative Physiology.
The study is published in the Journal of the American College of Cardiology.
Copyright © 2019 Knowridge Science Report. All rights reserved.