We all know the obvious consequences of poor sleep. We drag through our days feeling sluggish and irritable. However, two new studies have found that irregular sleep and poor sleeping patterns can increase your risk for heart disease.
“This study is one of the first investigations to provide evidence of a connection between irregular sleep duration and irregular sleep timing and atherosclerosis,” said the lead study author on one of the studies, Kelsie Full, an assistant professor of medicine in the epidemiology division at Vanderbilt Univ. Medical Center.
Atherosclerosis is the buildup of plaque in arteries that can lead to coronary heart disease, angina, heart attacks, strokes and carotid or peripheral artery disease. In the past, poor sleep quality had been linked to atherosclerosis. However, sleep regularity, like variations in how many hours of sleep people get on different nights and variations in bedtime, hadn’t been studied. This research found that people with a regular sleep pattern were the healthiest.
“Poor sleep is linked with several cardiovascular conditions, including heart disease, hypertension and [blood sugar concerns],” Prof. Full said. “Overall, we found that participants who slept varying amounts of hours throughout the week (meaning that one night they slept less, one night they slept more) were more likely to have atherosclerosis than participants who slept about the same amount of time each night.”
People whose sleep varied by 90 minutes to more than two hours within a week were about 1.4 times more likely to have calcified plaque in their arteries. They were also more likely to have stiff blood vessels.
The second study looked at the dangers of insomnia on long-term health. Having difficulty falling asleep for long periods can cause harm to the body. People with insomnia are 1.69 times more likely to have a heart attack. That risk is the same regardless of age or gender.
“Insomnia is actually quite common. We see it probably in one in 10 patients in the United States,” said Dr. Martha Gulati, director of prevention at the Cedars-Sinai Smidt Heart Institute.
The researchers believe that the constant lack of sleep may cause high levels of the stress hormone cortisol. Cortisol usually falls during sleep, and blood pressure decreases. The researchers think insomnia should be added to guidelines as a risk factor for heart disease.
“Now we have evidence that sleep is medicine,” said the study’s senior author, Dr. Hani Aiash, a cardiologist and assistant dean of interprofessional research in the College of Health Professions at Upstate Medical Univ. “So good sleep is prevention. If you didn’t sleep well… below five hours or six hours, you’re exposing yourself to a higher risk of myocardial infarction. The pattern of sleep is very important.”
When looked at together, these two new studies underscore the importance of having a regular sleep schedule. You should speak to your doctor if you struggle with sleep or irregular sleep patterns. Poor sleep doesn’t just impact your mood and day-to-day life. It may also seriously impact your heart health.