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WASHINGTON — When you don’t get enough sleep, the short-term consequences are noticeable — maybe you’re distracted at work or snappy with loved ones. But in the background, irregular and poor-quality sleep patterns could increase your risk of developing cardiovascular disease, according to a study published this week in the Journal of the American Heart Association.
“This study is one of the first investigations to provide evidence for a link between irregular sleep duration and irregular sleep patterns and atherosclerosis,” said study lead author Kelsie Full. assistant professor of medicine in the division of epidemiology at Vanderbilt University Medical Center in Nashville. .
Atherosclerosis is the buildup of plaque in the arteries, according to the American Heart Association. This plaque is made up of cholesterol, fatty substances, cellular waste, calcium and fibrin, a blood clotting agent. As plaque builds up, the walls of blood vessels thicken, which reduces blood flow and therefore decreases the amount of oxygen and other nutrients reaching the rest of the body. Atherosclerosis can lead to cardiovascular health issues, including coronary heart disease, angina pectoris, heart attacks, strokes, and carotid or peripheral artery disease.
Poor sleep—including poor quality, abnormal quantity, and fragmented sleep—has previously been associated with cardiovascular disease and cardiovascular disease-related death, but less is known about the specific associations between sleep regularity and sleep. atherosclerosis.
Sleep regularity, the authors of the new study defined, is estimated by variations in sleep duration (how long someone sleeps each night) and sleep timing (the time someone sleeps). ‘sleeps at night) – the less variation, the better.
The authors sought to learn more about this relationship by analyzing the sleep of older people – 69 years old on average – who participated in the Multiethnic Atherosclerosis Study, a longitudinal cohort study designed to investigate the prevalence and progression risk factors. for cardiovascular disease. More than 2,000 participants were recruited between 2000 and 2002 in Minnesota, Maryland, Illinois, North Carolina, California and New York State.
During sleep assessments conducted between 2010 and 2013, participants kept a sleep diary for seven consecutive days and wore a wristwatch that tracked their sleep and wake history. Participants also underwent a home sleep study to measure breathing, sleep stages, nighttime waking and heart rate.
After assessing participants’ cardiovascular health over the same period, the researchers found that those with irregular sleep duration – those that varied from 90 minutes to more than two hours in a week – were about 1.4 times more likely to have high coronary artery calcium scores. compared to those whose sleep durations are more constant. (This calcium score measures the amount of calcified plaque in the arteries; a higher number increases the risk of certain cardiovascular diseases.) The first group were also more likely to have carotid plaque and abnormal results on a test assessing the stiffness of blood vessels.
“These findings suggest that maintaining regular or habitual sleep durations, or sleeping approximately the same total duration each night,” Full said, “may play an important role in preventing cardiovascular disease.”
Sleep and cardiovascular risk
Since sleep quality and atherosclerosis were measured at the same time, the researchers were unable to assess or prove whether irregular sleep was the cause of the disease – they did not found only an association between the two.
Sleep is essential for the heart to rest, as this is when the heart rate slows down and blood pressure normally drops.
–Dr. Donald Lloyd Jones
The study results released Wednesday could be due to both a direct link between sleep and the heart, and/or other lifestyle factors.
“People who sleep less or have erratic habits tend to have less healthy habits in other lifestyles (like diet and physical activity),” said Dr Donald Lloyd-Jones, director from the Department of Preventive Medicine at Northwestern University Feinberg School of Medicine in Chicago. , said via email. Lloyd-Jones was not involved in the study.
“Sleep is essential for the heart to rest, because that’s when the heart rate slows down and blood pressure normally drops,” he added. “Without this regular rest, the heart and vascular system become stressed over time.”
Anything that interrupts a person’s sleep can lead to changes that affect the heart, said Dr. Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health in Denver. Freeman was not involved in the research.
“Interrupted sleep – especially (in) those with sleep apnea – usually releases catecholamines like adrenaline, which can do all sorts of things if it’s a chronic problem,” says Freeman. Sleep interruptions can also be a sign of increased stress or anxiety, he added.
Still, the study results were for participants with no history of cardiovascular disease, so everyone should take that into consideration, Lloyd-Jones said.
“Sleep matters to all of us,” he added. “It’s an important part of Life’s Essential 8 approach to optimizing your cardiovascular health – which can also help prevent cancers, dementia and many other chronic diseases of aging.”
Life’s Essential 8 is the American Heart Association’s checklist for good health throughout life, which also includes healthy eating, physical activity, smoking cessation, weight management, control cholesterol and blood sugar and blood pressure management.
The association recommends adults get seven to nine hours of sleep each night, which is more likely if you have good sleep hygiene. This includes going to bed at the same time every night, waking up at the same time every day, avoiding late morning caffeine, using your bedroom only for sleep and privacy, avoid using a screen before bed and sleep in a dark, quiet and cool room.
“I also recommend keeping a notebook by the bed,” Freeman said. “Then when people wake up in the middle of the night, (they should) write down what comes to mind first. Maybe they heard a bird or they might have to pee or “They’ve had a stressor in their mind. And that can be a focus for when they’re meditating or doing something mindful.”
If you have sleep apnea or persistent sleep problems, see a sleep specialist or another clinic.