- The researchers examined the relationship between cardiovascular risk and sleep quality.
- They found that better sleep quality is linked to lower cardiovascular risk.
- They noted that increasing awareness of sleep quality and quantity could benefit sleep quality and potentially reduce cardiovascular risk.
According to the American Sleep Association, 50-70 million adults in the United States have a sleep disorder. Of these, 25 million have obstructive sleep apnea (OSA), which is when the muscle at the back of the throat relaxes too much to allow regular breathing.
Most studies examining the link between sleep quality and cardiovascular risk have focused on one dimension of sleep: sleep duration or sleep apnea. Therefore, the combined effect of multiple dimensions of sleep on cardiovascular health remains unstudied.
Recently, researchers at the French National Institute for Health and Medical Research in Paris, France, investigated the joint effect of multiple sleep habits on the incidence of cardiovascular conditions.
They found that a healthier overall sleep score was linked to lower cardiovascular and stroke risk.
They presented their findings at this year’s European Society of Cardiology (ESC). Congress.
For the study, the researchers analyzed data collected between 2008 and 2011 from 7,203 men and women between the ages of 50 and 75. All were free of cardiovascular conditions at the start of the study.
Each participant underwent a physical examination and various biological tests. They also provided information on lifestyle and medical history. The researchers assessed the participants’ sleep habits through a questionnaire, looking at:
- sleep duration
- chronotype of waking up early, known as a “morning person”
- Sleep apnea
- Subjective daytime sleepiness.
Each dimension was assigned a score of 1 or 0. Criteria for a score of 1 or “healthy” included:
- early chronotype
- sleep duration of 7-8 hours per day
- rare or no insomnia
- no sleep apnea
- no frequent daytime sleepiness.
Overall sleep scores among participants ranged from 0 to 5. Among participants, 6.9% had a sleep score of 0 or 1, and 10.4% had an optimal sleep score of 5.
After a median follow-up of 8 years, the researchers noted that participants with a score of 5 (optimal sleep) had a 74% lower risk of cardiovascular conditions than those with the worst sleep quality.
They added that each one-point increase in healthy sleep score corresponded to a 22% reduction in cardiovascular risk.
When asked what might explain the link between poor sleep and increased cardiovascular and stroke risk, Dr. Aboubakari Nambiemapostdoctoral researcher at Université Paris Cité in France, one of the study’s authors, said Today’s medical news There are currently no definitive answers.
He noted that the American Heart Association recently updated its “
in conversation with MNT, Dr Saurav Luthraof the Division of Pulmonary, Intensive Care and Sleep Medicine at the University of Kansas Health System, explained some of these possible mechanisms:
“[Current research suggests] that healthy sleep is vital for resting the heart and brain. [In the absence of sleep], there may be increased inflammation, release of stress hormones, and decreased removal of toxins from the brain. These can trigger fluctuations in heart rate and increased blood pressure at night. We believe this can lead to heart conditions such as uncontrolled blood pressure (hypertension, irregular heart rhythms such as atrial fibrillation) and possibly cognitive problems [or] memory difficulty.”
“Sleep deprivation, if secondary to underlying sleep apnea, can also lead to increased risk of stroke/blood clots through inflammation, as well as a lack of oxygen at night and blood thick, resulting from chronic low blood oxygen levels,” he added. .
Dr Tadwalkar RiggedA board-certified cardiologist at Providence Saint John’s Health Center in Santa Monica, CA, who was not involved in the study, added that sleep deprivation disrupts the sympathetic nervous system, the body’s “fight or flight” response.
“The increased tone of the sympathetic nervous system is responsible for increased circulation of catecholamines, which are hormones that increase heart rate, blood pressure, and vascular resistance,” he added.
“Indirectly, lack of sleep contributes to the dysregulation of hormones involved in hunger. This contributes to obesity, which is a strong risk factor for cardiovascular disease,” she noted.
Dr Sanjay Patelprofessor of medicine, epidemiology, and clinical and translational science at the University of Pittsburgh, who was not involved in the study, said MNT that other factors could also be responsible for the observed results.
“We know that poverty leads to poorer sleep quality, and people with lower socioeconomic status have a much higher risk of heart disease and stroke. Similarly, anything that increases stress in life (having a sick child, caring for an elderly parent, having a very stressful job) will lead to poorer quality sleep and also increase the risk of heart disease and accident stroke,” explained Dr. Patel. .
“We can’t be completely sure from this study whether the associations that were found are caused by lack of sleep or related to some other factor,” he noted.
The researchers concluded that better sleep quality across multiple dimensions is associated with lower cardiovascular and stroke risk.
When asked about the limitations of the study, Dr Daniela Grimaldiresearch assistant professor at the Northwestern University Center for Sleep and Circadian Medicine, who was not involved in the study, said MNT:
“A limitation could be represented by the fact that these findings originate from self-report measures of sleep quality; It will be important for future studies to confirm these findings using subjective and objective measures of sleep quality.”
Dr Fiona Barwickclinical associate professor of psychiatry and behavioral sciences and sleep medicine at Stanford University, who was not involved in the study, explained some key problems with self-report measures of sleep quality.
“Self-reported estimates of total sleep time may be inaccurate, as people with insomnia often underestimate total sleep time, and good sleepers often overestimate total sleep time,” he noted. “Those who suffer from it do not always recognize sleep apnea unless they complete an overnight sleep study at home or in the laboratory because the obvious symptoms of sleep apnea, such as snoring, wheezing, or witnessed breathing difficulties, are not always present. present”.
“Even excessive daytime sleepiness can be masked by caffeine use,” added Dr. Barwick. “Self-report measures can also be inaccurate when it comes to certain lifestyle factors, as people are more likely to underreport how much they smoke, drink or exercise, in an effort to create a positive impression. Inaccuracies in self-reported data can make it difficult to get a clear and definitive picture of the relationship between sleep and health risks.”
Dr. Damian Stevensmedical director of the sleep laboratory at the University of Kansas Health System, who was not involved in the study, added that cause does not always mean effect.
“Just because they’re happening together doesn’t mean one is causing the other. For example, some patients may start sleeping poorly because they have chest pain or other symptoms of heart disease, so rather than poor sleep leading to heart problems, poor sleep can sometimes be a sign of heart disease,” he noted .
MNT also asked Dr Nour Makarem, assistant professor of epidemiology at Columbia University, not involved in the study, how to improve sleep quality. He noted that it’s important to prioritize sleep and that 7 to 8 hours of sleep a night is ideal for heart health.
“It’s also important to practice good sleep hygiene, which refers to putting yourself in the best position for a good night’s sleep by optimizing your sleep schedule, bedtime routine and sleep environment,” he noted.
“Follow a consistent sleep schedule, which means try to go to bed and wake up at the same time every day, and try to stick to the same sleep schedule on weekdays and weekends to avoid disrupting your sleep-wake rhythm of your biological clock. Use the hour before bed to relax and unwind, and optimize your sleep environment by making your bedroom comfortable, quiet, cool, and dark,” Dr. Makarem advised.
“Get rid of distractions like bright light and noise. For example, wear thick curtains or an eye mask to keep light from disrupting your sleep, and avoid bright light sources like computers, TVs, and phones. Also, try to drown out any noise by using earplugs or a white noise machine, and avoid stimulants like nicotine and caffeine,” he continued.
Dr. Nambiema concluded that, from a public health point of view, it is essential to increase awareness and health literacy about sleep quality.
Said “[t]in fact, it could start early in life, and elementary school could represent a wonderful window of opportunity for this. It is important to highlight that this must be a continuing education program adapted to each level of the school”.