Better Sleep Linked With Reduced Risk of CVD, Improved Weight Loss

Improved sleep patterns were linked with potential risk reductions of heart attacks, strokes, and other cardiovascular diseases (CVDs) with additional associations found in helping women achieve and maintain a healthier body weight, according to preliminary research to be presented in 2 studies at the American Heart Association's (AHA) Epidemiology and Prevention (EPI) | Lifestyle and Cardiometabolic Health Scientific Sessions 2020.

The 2 abstracts, “The role of sleep as a cardiovascular health metric: Does it improve cardiovascular disease risk prediction? Results from the multi-ethnic study of atherosclerosis,”¹ and “Impact of change in bedtime variability on body composition: Secondary findings from the Go Red for women strategically focused research network,”² are to be presented at the EPI | Lifestyle Scientific Sessions 2020 from March 3-6 in Phoenix, Arizona.

The link between impaired sleep quality and duration has been linked with negative health outcomes in the past, with irregular sleep schedules shown to contribute to a higher risk of type 2 diabetes and obesity. The role of irregular sleep schedules in contributing to CVDs was additionally highlighted in a 5-year study published Monday in the Journal of the American College of Cardiology,³ which found that participants with the most irregular sleep duration or timing had more than double the risk of developing a CVD event over the follow-up period compared to those with the most regular sleep patterns.

In research presented at the EPI | Lifestyle Scientific Sessions 2020, study authors sought to examine whether the incorporation of sleep metrics into the AHA Life’s Simple 7 (LS7), a measure of cardiovascular health (CVH), would result in stronger associations with CVD outcomes than current LS7 metrics (tobacco use, body weight, diet, physical activity, cholesterol, blood pressure and glucose levels).

Researchers examined 1920 diverse adults (mean age: 69.5 years) in the MESA Sleep Study, who completed 7 days of wrist actigraphy, overnight in-home polysomnography, and sleep questionnaires. Data utilizing LS7 alone and in conjunction with 4 new CVH scores incorporating aspects of sleep were compared using logistic regression and cox proportional hazards models in relation to CVD prevalence and incidence.

In the study findings, researchers found that when sleep duration was added to the LS7 as an eighth metric of CVH, the heart health score was more strongly associated with heart disease. Participants determined to have the healthiest sleep duration (7-8 hours), in addition to meeting LS7’s guidelines, were 61% less likely to have a heart disease diagnosis, compared to those with the poorest scores (less than 6 hours or more than 9 hours). Additionally, participants meeting the LS7 who had healthy sleep behaviors and no sleep disorders had up to 59% lower likelihood of having a heart attack, stroke, heart failure, or other cardiovascular event at baseline and up to 44% lower risk of developing heart disease at mean follow-up (4.4 years).

As the LS7 score alone was not significantly associated with CVD prevalence or incidence in the study, the improved risk determination found by the addition of sleep metrics could prove vital in determining CVD risk.

"These findings underscore the importance of embracing a holistic vision of sleep health that includes both sleep behaviors and sleep disorders when assessing cardiovascular risk. The approach to promoting a healthy lifestyle for heart disease prevention, which traditionally focused on diet and exercise, should be expanded to include sleep," said lead study author Nour Makarem, PhD, associate research scientist at Columbia University's Vagelos College of Physicians and Surgeons.

One of the 7 metrics involved in the LS7, body weight, was additionally the focus of a separate study presented at the conference examining bedtime variability on body composition in women, and whether reducing variability in sleep schedules contributed to improvement in markers of disease risk. The study involved 37 women, ages 22 to 46, with a body weight classified at baseline as either normal or overweight, but not obese.

Researchers examined participants over separate 6-week periods during which women were instructed to maintain healthy, habitual sleep patterns. These findings were compared with the 2 weeks prior to intervention, where bedtimes and sleep duration were determined using wrist-worn actigraphy (ranging from 7-9 hours a night).

Among the study cohort, the number of hours each woman slept did not change, but in those who exhibited improvements in sleep regularity (n = 29), decreased bedtime variability compared with those with no change or increased bedtime variability was associated with a significant reduction in total weight (reduced: —0.52 [0.98] vs increase/no change: 0.63 [0.41] L, P <.001) and subcutaneous adipose tissue (reduced: —0.48 [0.86] vs increase/no change: 0.56 [0.31] L, P <.001).

While further research is being conducted on this study, preliminary results suggest that improving upon irregular sleep schedules can result in achieving a healthier body weight.

Reference

1. Makarem N, Castro-Diehl C, St-Onge MP, et al. The role of sleep as a cardiovascular health metric: Does it improve cardiovascular disease risk prediction? Results from the multi-ethnic study of atherosclerosis. Presented at the American Heart Association's Epidemiology and Prevention | Lifestyle and Cardiometabolic Health Scientific Sessions 2020, Phoenix, Arizona; March 3-5. Presentation: 36.
2. St-Onge MP, Campbell A, Zuraikat FM, et al. Impact of change in bedtime variability on body composition: secondary findings from the Go Red for women strategically focused research network. Presented at the American Heart Association's Epidemiology and Prevention | Lifestyle and Cardiometabolic Health Scientific Sessions 2020, Phoenix, Arizona; March 3-5. Presentation: MP19.
3. Huang T, Mariani S, Redline S. Sleep irregularity and risk of cardiovascular events: the multi-ethnic study of atherosclerosis [published online March 2, 2020]. J Am Coll Cardiol. doi: 10.1016/j.jacc.2019.12.054.