Sleep and atrial fibrillation: a study of 52,952 people

The study, published in JACC: Advances (2025), analyses the association between sleep stages measured with wearable devices and the development of atrial fibrillation in 52,952 participants from the All of Us Research Program, followed for a median of 935 days. Over that period, 437 people developed atrial fibrillation.

The concrete numbers

Participants who went on to develop atrial fibrillation already showed, at the start of the study, shorter deep sleep (0.82 versus 0.98 hours, p<0.001) and shorter REM sleep (1.14 versus 1.31 hours, p<0.001) than those who did not.

In both cases the difference is about ten minutes a night, seen on average across a very large group.

Longer total sleep, less deep and REM sleep and more light sleep are independently associated with the risk of atrial fibrillation.

“Independent” means the finding holds even after taking into account age, sex, BMI, hypertension, diabetes and other traditional risk factors. The authors point to a possible role in risk stratification and prevention.

What remains

It is an observational study: it shows an association in a group. It does not show that changing your sleep stages protects your heart, and it says nothing about the risk of any single person.

The Digital Twin lines up the data your devices write to your phone, such as steps, heart rate and sleep, and shows you how they change over time. It does not build cardiovascular risk profiles and it does not diagnose: this research describes groups of people, not you. These are data to read together with your doctor.