What’s the best sleep pattern for hearts?
Keeping to a regular bedtime and wake time are important for heart and metabolic health among older patients, a study suggests.
People with irregular sleep patterns weigh more, have higher blood sugar, higher blood pressure, and are at more risk of having a heart attack or stroke within 10 years than those who sleep and wake at the same times every day, the authors report.
In their study of almost 2000 older adults, irregular sleepers were also more likely to report depression and stress than regular sleepers.
The US researchers said their findings showed a regular bedtime and wake time were as important for heart and metabolic health among older adults as the length of time they sleep.
They used data from people in a longitudinal study, aged between 54 and 93, with an average age of 69. Participants used a wrist-worn device to track sleep schedules for seven days and kept a sleep diary. People with diagnosed sleep disorders such as sleep apnoea were excluded and follow-up was for about 10 years.
Researchers assessed the regularity of their sleep patterns as well as the duration and preferred timing: whether someone was a night owl or turned in early.
People with hypertension tended to sleep more hours and people with obesity tended to stay up later.
Of all three measures, however, regularity was the best at predicting someone's heart and metabolic disease risk, the researchers found.
"From our study, we can't conclude that sleep irregularity results in health risks or whether health conditions affect sleep," said the study’s lead author Dr Jessica Lunsford-Avery, (PhD), an assistant professor in psychiatry and behavioural sciences at Duke University Medical Center, North Carolina.
"Perhaps there's something about obesity that disrupts sleep regularity. Or as some research suggests, perhaps poor sleep interferes with the body's metabolism, which can lead to weight gain. It's a vicious cycle.”