Sleeping at least seven hours each night can reduce the risk of heart attack or stroke.
Studies conducted in mice indicate that rodents that do not receive a sufficiently closed eye are more likely to develop atherosclerosis, a disease in which plaque builds up on the inner walls of the arteries.
Previous studies have shown that lack of sleep increases the risk of cardiovascular disease, but researchers have not been able to explain how.
The team at the Massachusetts General Hospital in Boston says his study is the first to show that the brain part of sleep is linked to bone marrow and may increase the production of white blood cells that are known to cause atherosclerosis.
A new study found that getting less than seven hours of sleep each night may increase the risk of developing atherosclerosis, a disease in which the plaque accumulates on the inner walls of the arteries (image file)
The National Sleep Foundation recommends that adults sleep between seven and nine o'clock each night.
However, a 2015 Disease Control and Disease Research Center found that about 50% of adults in the United States are sleeping less than the recommended hours.
Insufficient sleep has been shown to increase the risk of obesity, diabetes, heart disease and even cancer, but researchers do not know much about the underlying mechanisms that cause it.
"We started with the premise that we know that sleep is good for your heart, good for cardiovascular diseases, and sleep disturbance is bad for your health and we have known it for a long time," said senior author Dr. Philip Suvarsky, Associate Professor at Massachusetts General and Harvard Medical School, DailyMail.com reported.
– Our question was: "How?". We wanted to investigate this known risk factor in order to potentially identify tissue, cellular or molecular pathways that could explain this link.
For the study published in Nature, the team genetically programmed laboratory mice to develop arterial disease.
One group of mice was allowed to sleep without interruption for at least seven hours, and the other group was repeatedly interrupted, like a man who was constantly awakening due to noise.
None of the two groups had changes in weight or cholesterol levels.
However, sleep-deficient mice had more arterial plaques in their blood vessels than mice that were allowed to sleep normally.
Mice that have interrupted sleep also have higher levels of two white blood cells, monocytes and neutrophils that play a role in atherosclerosis.
Researchers have found that hypocretin, a hormone produced in the hypothalamic brain region that promotes alertness and appetite, controls the production of white blood cells in the bone marrow.
The levels are usually high when animals are awake, but they were very low in sleep-mice.
The decline in the hormone leads to high levels of monocytes and neutrophils, which in turn leads to atherosclerosis.
"Identifying the link between … the brain area that promotes alertness, appetite, and the way it communicates directly with the bone marrow was a surprise," Dr. Swirski said.
Dr. Swirski said he hopes to explore this time with people and see if there are consequences of sleep in future research.
"We know that the bone marrow cells fight infection and are related to cancer and cardiovascular disease. We have more questions to answer, "he said.
He added that a cultural change must be made in the United States so that adults become aware of the importance of sleep.
"We do not excuse playing in words – we are waking up for the benefits of high-quality sleep," said Dr. Svisary.
"The idea of how to be successful is work, work, work. People are proud of not sleep enough because they are so busy.
"We have to change this perception and realize that you will be more productive, healthier and happier if you maintain a regular high-quality sleep cycle."