Cardiovascular health (CVH) scores that include sleep predicted CV disease risk among older U.S. adults, supporting the American Heart Association’s recent inclusion of sleep in its own checklist.
“Our study is the first to show that sleep metrics add independent predictive value for CVD events over and above the original seven cardiovascular health metrics, providing support for updating the guidelines from Life’s Simple 7 (LS7) to Life’s Essential 8,” lead author Nour Makarem, PhD, of the Mailman School of Public Health at Columbia University Irving Medical Center, New York, said in an interview.
For the study, her team compared four versions of LS7 checklists that included sleep in relation to cardiovascular disease (CVD) risk.
“CVH scores that included sleep duration alone as a measure of overall sleep health, as well as scores that included multiple dimensions of sleep health (that is, sleep duration, efficiency, and regularity, daytime sleepiness, and sleep disorders), were both predictive of future CVD,” she said.
Study participants scoring in the highest tertile of the CVH checklists that included sleep had up to a 47% lower CVD risk.
Sleeping 7 hours or more but less than 9 hours nightly was considered “ideal,” according to the study, which was published online in the Journal of the American Heart Association.
Lower the odds
Dr. Makarem and colleagues analyzed data from participants in the Multi-Ethnic Study of Atherosclerosis (MESA) sleep study using overnight polysomnography, 7-day wrist actigraphy, validated questionnaires, and outcomes. They used the data to evaluate the four iterations of an expanded LS7 score:
- Score 1 included sleep duration;
- Score 2 included sleep characteristics linked to CVD in the literature (sleep duration, insomnia, daytime sleepiness, and obstructive sleep apnea [OSA]);
- Score 3 included sleep characteristics associated with CVD in MESA (sleep duration and efficiency, daytime sleepiness, and OSA); and
- Score 4, also based on CVD in MESA, included sleep regularity.
Among 1,920 participants (mean age 69 years; 54% women; 40%, White individuals), the mean LS7 score was 7.3, and the means of the alternate CVH scores that included sleep ranged from 7.4 to 7.8 (scores range from 0 to 14, with higher scores indicating better CVH).
On actigraphy, 63% of participants slept less than 7 hours; 30% slept less than 6 hours; 39% had high night-to-night variability in sleep duration; and 25% had high variability in sleep onset timing.
Overall, 10% had sleep efficiency less than 85%; 14% had excessive daytime sleepiness; 36% had high insomnia symptoms; and 47% had moderate to severe OSA. Short-duration sleepers also had a higher prevalence of overweight/obesity, diabetes, and hypertension and had lower mean LS7 scores.
During a mean follow-up of 4.4 years, 95 prevalent CVD events and 93 incident cases occurred.
Higher scores on all four expanded versions were related to lower odds of having CVD. Participants in the highest versus the lowest tertile of the LS7 score had 75% lower CVD odds (odds ratio, 0.25). Similarly, those in the highest versus the lowest tertile of CVH scores 1 and 2 had 71% and 80% lower odds of prevalent CVD (OR, 0.29 and OR, 0.20), respectively.
Overall, participants in the highest versus lowest tertile of the LS7 score and all CVH scores had up to 80% lower odds of prevalent CVD; those in the highest versus lowest tertile of CVH score 1, which included sleep duration, and CVH score 4, which included multidimensional sleep health, had 43% and 47% lower incident CVD risk (hazard ratios, 0.57 and 0.53), respectively.
The LS7 score alone was not significantly associated with CVD incidence (HR, 0.62).
“Clinicians should ask patients about their sleep health and emphasize the importance of prioritizing sleep for heart disease prevention,” Dr. Makarem said.