misaligned with our circadian rhythm,” Dr. Harly Greenberg, chief of the division of pulmonary, critical care and sleep medicine at Northwell Health in New Hyde Park, N.Y. says.
What the research shows
For the study, Plans and his colleagues collected data on more than 88,000 men and women, average age 61, recruited between 2006 and 2010.
The researchers had information on when participants went to sleep and woke up over a week by using accelerometers worn on the wrist. Participants also completed questionnaires about lifestyle and health.
Over an average follow-up of nearly six years, 3.6% of the participants developed heart disease. Most of those who developed it went to sleep at midnight or later. People who were least likely to develop cardiovascular disease went to sleep between 10 p.m. and 10:59 p.m., the researchers found.
Those who went to sleep between 11 and 11:59 p.m. had a 12% higher risk, and those who went to sleep before 10 p.m. had a 24% higher risk.
After accounting for gender, the researchers found that the risk was greatest among women. Among men, only going to sleep before 10 p.m. remained significant, the researchers note.
What is the best sleep routine?
“There is good evidence that morning light resets your circadian rhythm, and thus it may be beneficial to practice good sleep hygiene,” Plans advises.
He provided the following tips for practicing good sleep hygiene:
- Go to sleep at a reasonable hour and wake up early enough to get some outside time in the morning.
- Avoid blue light at night.
- Avoid caffeine late in the day.
- Avoid naps after 4 p.m.
- Use the bedroom only for sleeping.
- Only go to bed when you feel like you are ready to sleep.
“These findings provide potential insights into how the timing of sleep onset relative to circadian rhythms may influence cardiovascular health. However, further studies are needed, and it remains to be demonstrated whether one changing the time of day they go to sleep would increase or decrease cardiovascular event risk,” Dr. Gregg Fonarow, director of the Ahmanson-UCLA Cardiomyopathy Center in Los Angeles says.