04/11/2023
Get a Good Night's Sleep: Your Heart Will Thank You for It
Roseline Péluchon, MD
The link between poor sleep quality and cardiovascular risk is already well documented. However, most studies only consider one or two aspects of sleep (for example, sleep duration or sleep apnea), investigating one sleep pattern at one point in time.
A team from Inserm, France's National Institute of Health and Medical Research, published the results of a more complete study of how sleep affects cardiovascular risk. The study examines five sleep patterns that determine sleep quality: sleep duration, insomnia, chronotype ("eveningness" or "morningness"), sleep apnea, and daytime drowsiness. These patterns formed the basis of a questionnaire given to the study participants, providing each with a sleep score between 0 (disturbed sleep) and 5 (perfect sleep). Perfect sleep is characterized by 7-8 hours of sleep per night, getting up early and going to bed early, no insomnia, no sleep apnea, and no excessive daytime drowsiness.
Cardiovascular Risk Reduction
The questionnaire was given to two cohorts taking part in population surveys. The sleep score was calculated on enrollment and 2 years later for one of the studies and 5 years later for the other. A subgroup of participants also underwent polysomnography testing. The aim of the study was to assess the overall effect on cardiovascular risk of the five sleep patterns and their change over time. The study involved more than 11,000 people aged 53-64 years (44.6% women), and cardiovascular follow-up was conducted for eigh8-10 years.
The data analysis provided three main observations. The first is that the higher the initial sleep score, the lower the cardiovascular risk. The risk is reduced by 18% for each additional point from the initial sleep score (hazard ratio [HR], 0.82). The second finding is that risk is reduced by 16% per additional score point between the two evaluations (HR, 0.84). Finally, the authors estimate that the data collected is evidence that between 30% and 60% of new cardiovascular accidents would be prevented if all participants achieved the maximum level for at least four sleep characteristics.
Room for Improvement
It should be noted that 2 out of 3 patients got a high sleep score (three or above) from the first assessment, and this score remained stable between follow-ups. Approximately 8% of participants improved their score, whereas 11% saw their score drop below three. Finally, for some participants (17.2%), the score remained stable but below three. Future research should focus on these last two groups, according to the authors, to look for potentially modifiable determinants to reverse these trends.
The link between good sleep quality and reduced cardiovascular disease risk is stronger for people with a good initial score, illustrating the importance of achieving good sleep quality as early as possible in life and maintaining it on a long-term basis. Nevertheless, the reduced risk associated with an improvement in score over time in people with an initially low score suggests that it is never too late to improve sleep quality, however low the initial score is.
The authors propose making the general public aware very early on of the importance of sleep quality and quantity. They also recommend screening for and treating chronic insomnia, circadian rhythm sleep disorders, and sleep apnea as early as possible. Cognitive-behavioral therapy is effective in treating insomnia, and several lines of efficient therapies exist for obstructive sleep apnea according to its phenotype and severity. "Morningness" or "eveningness" is thought to be highly influenced by genetics and is expressed as a preference rather than a modifiable behavior, even though behavioral measures combined with chronotherapy (light therapy, use of melatonin) can be used in people with misalignment of their biological clock and their environment in circadian rhythm sleep–wake disorders. Solutions may also come from the training of healthcare professionals.
This study may pave the way for promoting healthy sleep and further encourage strong collaboration between sleep and cardiovascular medicine.
This article was translated from JIM , which is part of the Medscape professional network.
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