The link between sleep and a healthy heart has been well established, a new study reveals there may be an optimal time for falling asleep.

Collecting data from 103, 712 UK Biobank participants (in majority white people between 43 to 79 years old) over a period of 7 days they found 3172 cases of cardiovascular disease (CVD) during a follow-up period of 5.7 years.

They discovered that sleep onset time of 10:00 pm – 10:59 pm was associated with the lowest CVD incidence.

This association with increased CVD risk was stronger in females.

The researchers also found that falling asleep after midnight or before 10 pm both was associated with around a 25% increase in CVD. This increase in risk dropped to 12% for those who fell asleep between 11-12 pm.