Written by Joyce Smith, BS. In a large prospective study, a healthy sleep pattern was associated with reduced risks of cardiovascular disease (CVD), coronary heart disease (CHD), and stroke among participants with varying levels of genetic risk.
Studies have shown that our genes, as well as lifestyle, may interact to influence the development of CVD 1-3. However, no study has explored the mechanism by which a combination of sleep behaviors might affect CVD risk or whether these sleep behaviors might act individually through several mechanisms that, when operating synergistically, increase the risk of CVD. This current observational study 4, based on the U.K. Biobank study, assessed potential associations between sleep behaviors and CVD risk, as well as sleep patterns and genetic susceptibility to CVD outcomes. Potential genetic -sleep interactions were also noted.
Fan and colleagues established a “healthy sleep” score based on sleep patterns and a “genetic risk” score using genetic variations called SNPs (single nucleotide polymorphisms) that were already known to be linked to the development of heart disease and stroke. They analyzed the SNPs from blood samples that were taken from more than 385,292 healthy participants in the U.K. Biobank project and used them to create a genetic risk score to determine whether the participants were at high, intermediate or low risk of cardiovascular disease.
- Participants were followed for a median of 8.5 years, during which time there were 7,280 cases of CVD, including 4,667 of CHD, and 2,650 of stroke.
- Participants with higher healthy sleep scores had lower BMI measurements, lower prevalence of pre-existing hypertension and diabetes, were physically active, were more likely to be women, and were less likely to be non-smokers.
- Compared to those with unhealthy sleep patterns, those with good sleeping habits had a significantly reduced risk of CVD, CHD and stroke (35%, 34% and 34% respectively). Those with the healthiest sleep patterns slept 7-8 hours a night, never or rarely experienced insomnia, and did not snore or experience any daytime drowsiness.
- Poor sleep patterns accounted for almost 10% of cardiovascular events in this cohort. Study participants with poor sleep pattern and high genetic risk showed the highest risk of CHD and stroke.
- Those with both a high genetic risk and a poor sleep pattern had a more than 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. (This translates into 11 more cases of heart disease and five more cases of stroke per 1000 people a year among poor sleepers with a high genetic risk compared to good sleepers with a low genetic risk.)
- Those with both high genetic risk and a healthy sleep pattern had a 2.1 fold greater risk of heart disease and a 1.3 fold greater risk of stroke compared to those with a low genetic risk and a healthy sleep pattern.
- An unhealthy sleep pattern and a low generic risk resulted in a 1.7 fold greater risk of heart disease and a 1.6 fold greater risk of stroke.
Treating the sleep disorders may play an important role in the primary prevention of CVD and other related disorders regardless of the individuals’ genetic risk profile.
This was an observational study which allowed for associations only, no causation. Other study limitations included the use of self-reported sleep data that may have resulted in misclassification of sleep data such as the exclusion of restless leg syndrome. Also, the restriction of participants to those of European descent prevented generalization of results to other ethnic groups. However, an important study strength included the large sample size (385,292 participants) and the use of a prospective study design that allowed for the examination of associations of CVD events with both sleep patterns and genetic risk.
Source: Fan, Mangy, 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 (2019).
© The Author(s) 2019
Posted January 21, 2020.
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:
- Qi Q, Li Y, Chomistek AK, et al. Television watching, leisure time physical activity, and the genetic predisposition in relation to body mass index in women and men. Circulation. 2012;126(15):1821-1827.
- Wang T, Heianza Y, Sun D, et al. Improving adherence to healthy dietary patterns, genetic risk, and long term weight gain: gene-diet interaction analysis in two prospective cohort studies. Bmj. 2018;360:j5644.
- Qi Q, Chu AY, Kang JH, et al. Sugar-sweetened beverages and genetic risk of obesity. The New England journal of medicine. 2012;367(15):1387-1396.
- 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. European Heart Journal. 2019.
