Are Sleep Patterns and Genetics Associated with Incidence of Cardiovascular Disease?

Written by Joyce Smith, BS. This study suggests that healthy sleep patterns are associated with reduced risks of CVD, CHD, and stroke regardless of genetic risk patterns.

With CVD, CHD, and stoke increasing globally, ¹ there is also increasing evidence suggesting that unhealthy sleep patterns may be a contributing factor ². Studies have revealed that insomnia ³, snoring ⁴, sleep duration ^5,6, and excessive daytime sleepiness ⁷ are all associated with a 10-40% increased risk of CVD. While previous research on sleep has focused on individual sleep issues, no study, to date, has investigated jointly the above sleep patterns and their risk of CVD or clarified whether healthy sleep patterns could offset the effect of genetic predispositions to CVD. This study assesses a potential association between sleep behaviors and genetic susceptibility to CVD.

Fan and colleagues, ⁸ in a prospective study of 357,246 healthy participants (only European descent) in the UK Biobank project, analyzed the SNPs (single nucleotide polymorphisms known to increase CVD risk) from blood samples and used them to create a genetic risk score to determine whether the participants were at high, intermediate or low risk of cardiovascular problems. The research team established a healthy sleep score ranging from 0 to 5, with 5 being the healthiest sleep pattern that represented a ‘morning” person who slept between 7-8 hours a night without insomnia, snoring or daytime sleepiness. Weighted genetic scores of stroke and coronary heart disease were calculated to estimate the proportion of cardiovascular events that theoretically would not have occurred if all participants had a healthy sleep pattern. As well, the joint association of sleep pattern and genetic susceptibility with CVD outcomes was explored. The primary outcomes in the study were incident CVD and its two major component endpoints-CHD and stoke.

During the median follow-up of 8.5years, there were 7,280 cases of CVD including 4,667 of heart disease or 2,650 of stroke. The following calculations were made:

• Participants with the healthiest sleep patterns (score of 5) slept 7 to 8 hours a night, without insomnia, snoring or daytime drowsiness.
• Those with good sleeping habits had a 35% reduced risk of CVD and a 34% reduced risk of both heart disease and stroke compared to poor sleepers. Nearly 10% of cardiovascular events could be attributed to poor sleep patterns.
• Participants with both a high genetic risk and a poor sleep pattern had a 2.5-fold greater risk of heart disease and a 1.5-fold greater risk of stroke compared to those with a low genetic risk and a healthy sleep pattern. For poor sleepers with a high genetic risk, this translates into 11 more cases of heart disease and five more cases of stroke annually per 1000 people compared to good sleepers with a low genetic risk.
• For those with a low genetic risk, but an unhealthy sleep pattern, the risk of heart disease was 1.7-fold higher and the risk of stroke was 1.6-fold higher.

While this study shows no statistically significant association between healthy sleep scores and genetic susceptibility to CHD or stroke, the results suggest that a high genetic risk could be partly offset by a healthy sleep pattern; however, individuals with a low genetic risk could lose their inherent protection if they had a poor sleep pattern.

This study was observational, and allowed for only an association rather than a causal relationship

between sleep patterns and CVD risk. Other limitations included the bias of self-reported sleep data, a potential misclassification of a healthy sleep score which did not include all the sleep behaviors such as restless legs syndrome that could additionally increase cardiovascular risk ⁹. The study also neglected to account for changes in sleep behaviors before and after assessment which could have affected the sleep scores.

Source: Fan, Mengyu, Dianjianyi Sun, Tao Zhou, Yoriko Heianza, Jun Lv, Liming Li, and Lu Qi. “Sleep patterns, genetic susceptibility, and incident cardiovascular disease: a prospective study of 385 292 UK biobank participants.” European heart journal 41, no. 11 (2020): 1182-1189.

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Posted March 16, 2021.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

References:

1. GBD 2016 Causes of Death Collaborators. Global, regional, and national age-sex specific mortality for 264 causes of death, 1980-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet. 2017;390(10100):1151-1210.
2. Tobaldini E, Costantino G, Solbiati M, et al. Sleep, sleep deprivation, autonomic nervous system and cardiovascular diseases. Neuroscience and biobehavioral reviews. 2017;74(Pt B):321-329.
3. Hsu CY, Chen YT, Chen MH, et al. The Association Between Insomnia and Increased Future Cardiovascular Events: A Nationwide Population-Based Study. Psychosom Med. 2015;77(7):743-751.
4. Li M, Li K, Zhang XW, Hou WS, Tang ZY. Habitual snoring and risk of stroke: A meta-analysis of prospective studies. International journal of cardiology. 2015;185:46-49.
5. Li W, Wang D, Cao S, et al. Sleep duration and risk of stroke events and stroke mortality: A systematic review and meta-analysis of prospective cohort studies. International journal of cardiology. 2016;223:870-876.
6. Wang D, Li W, Cui X, et al. Sleep duration and risk of coronary heart disease: A systematic review and meta-analysis of prospective cohort studies. International journal of cardiology. 2016;219:231-239.
7. Boden-Albala B, Roberts ET, Bazil C, et al. Daytime sleepiness and risk of stroke and vascular disease: findings from the Northern Manhattan Study (NOMAS). Circulation Cardiovascular quality and outcomes. 2012;5(4):500-507.
8. Fan M, Sun D, Zhou T, et al. Sleep patterns, genetic susceptibility, and incident cardiovascular disease: a prospective study of 385 292 UK biobank participants. Eur Heart J. 2020;41(11):1182-1189.
9. Winkelman JW, Shahar E, Sharief I, Gottlieb DJ. Association of restless legs syndrome and cardiovascular disease in the Sleep Heart Health Study. Neurology. 2008;70(1):35-42.