Healthy sleep habits may help cut CVD risk, weight loss

Having sufficient and healthy sleep, in addition to adopting healthy lifestyle based on the AHA* Life’s Simple 7 (LS7) guidelines, can reduce the risk of cardiovascular diseases (CVD), according to the longitudinal MESA** Sleep Study presented at EPI Lifestyle 2020 Scientific Sessions.

“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 author Dr Nour Makarem of Columbia University in New York, New York, US.

Reviewing data of 1,920 adult participants (mean age 69.5 years), the researchers found that CVD prevalence and the risk of developing CVD were not significantly different between those with the highest LS7 score (tertile 3) vs the lowest LS7 score (tertile 1). [EPI Lifestyle 2020, abstract 36]  

However, when sleep duration was included as an additional health metric on top of LS7, participants in the highest score tertile were 61 percent less likely to have prevalent CVD than those in the lowest score tertile (odds ratio [OR], 0.39, 95 percent confidence interval [CI], 0.22–0.69). They also had a 44 percent lower risk of developing CVD during a mean follow-up of 4.4 years.

In this scoring system, a sleep duration between 7–9 hours was considered ideal and assigned the highest sleep score of 2, while those with poor sleep duration of <6 or >9 hours were assigned the lowest sleep score of zero. Intermediate sleep duration of ≥6 to <7 hours was scored as 1.

In addition, health metric that took into account sleep behaviours such as sleeping poorly (indicated by excessive daytime sleepiness), irregular bedtimes, poor sleep duration, or having sleep disorders (insomnia or sleep apnoea) on top of LS7 also better predicted CVD prevalence than using LS7 alone.

Participants with healthy sleep behaviours, in addition to meeting the criteria in LS7, were 59 percent less likely to have CVD compared with those in the lowest score tertile (OR, 0.41, 95 percent CI, 0.23–0.73).   

“Cardiovascular health [CVH] scores that include sleep were more strongly associated with CVD prevalence and incidence than the traditional LS7 score. The incorporation of sleep as a metric of CVH, akin to other health behaviours, may improve CVD risk prediction,” said Makarem.  

“This study adds to the knowledge base … It may soon be time to add sleep to LS7. We could call it Life’s Essential 8,” said Dr Eduardo Sanchez, AHA Chief Medical Officer for Prevention and Chief of the Center for Health Metrics and Evaluation, who was not affiliated with the study.

A separate study showed that, besides benefitting the heart, having a healthy sleep pattern could also benefit the waistline. The study compared the bedtime of 37 women (mean age 34.9 years) and followed up on their weight after 6 weeks. [EPI Lifestyle 2020, abstract MP19]

Intriguingly, women who maintained regular bedtimes daily throughout the study saw their body fat reduced by 2 pounds over 6 weeks compared with women with irregular bedtimes (p<0.001), even though both groups had similar sleep duration.  

“[The study shows that] reducing bedtime variability can improve body composition over time,” said lead author Dr Marie-Pierre St-Onge, also from Columbia University.

“Given that bedtimes are highly individualized, this may provide an easy public health message to maintain healthy sleep hygiene, particularly stable bedtime routine, to achieve better weight management and reduced CVD risk,” she concluded.