Irregular bedtime raises heart attack risk - study

Failing to stick to a regular time for going to bed and waking up increases the risk of stroke, heart attack and heart failure by 26%, even for those who get a full night's sleep, the most comprehensive study of its kind suggests.

- Andrew Gregory

Previous studies have focused on the links between sleep duration and health outcomes, with people advised to get between seven and nine hours of shut-eye a night.

That advice still stands. However, researchers are increasingly focusing on sleep patterns, and in particular the impact of irregular sleep - defined as variations in the time a person goes to sleep and wakes up.

The new study found irregular sleep - going to bed and waking up at different times each day - was "strongly associated" with a higher risk of major adverse cardiovascular events. Even getting eight hours of sleep was insufficient to offset the harmful effects of consistently varying bed and wake-up times, experts said.

The research, published in the Journal of Epidemiology and Community Health, involved 72,269 people aged 40 to 79 from the UK Biobank study. It did not establish precisely how close you have to get to the same bed and wake-up timeonly that the further away you are, the higher the risk of harm.