Not just for kids - a regular bedtime could be just as important for adults

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We all know that getting enough sleep is critical for our physical and mental wellbeing. And as a mother of two toddlers, I can tell you that I haven't had nearly enough in a very long time.

Now, a new study published in Scientific Reports has complicated matters even further by showing that a regular bedtime and wake time could be just as important as sleep duration when it comes to our health.

The two year study of 1,978 adults by the Duke University Medical Centre, found that people with varied sleep-wake times weigh more, have higher blood pressure and are at an increased risk of having a stroke or heart attack within 10 years than those who slept and woke at the same times every day.

Mental health was also impacted - with irregular sleepers more likely to report stress and depression.

Say what? It's hard enough to get anywhere even close to the recommended seven to nine hours each night, but a consistent sleep and wake time is a pipe dream for most parents, not to mention shift workers or anyone with a demanding schedule.

Believe me, there is nothing I'd love more than to be tucked in at 9.30pm every night with a bedtime story and blankie, but this simply isn't realistic.

And don't get me started on my wake time - which is under the complete control of the small humans in my care, and usually triggered by a kick to my forehead from the three-year-old that winds up in my bed each night.

Tracking and scoring sleep regularity 

For the study, participants wore sleep devices for a full week that tracked their sleep schedules down to the minute. They also kept a sleep diary. From this data, researchers assigned each participant a "sleep regularity index" score and were able to assess whether even subtle changes - eg. going to be at 10.10pm instead of 10pm - were linked to the participants' health.

The study also tracked the duration of participants' sleep and whether someone turned in early or was a night owl. According to these measures, people with hypertension tended to sleep more hours, and people with obesity tended to stay up later.

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Of all three measures, sleep regularity - the time the participant went to sleep and woke up - was the best at predicting someone's heart and metabolic disease risk. 

Implications 

The study certainly supports previous research that has linked irregular sleep/wake patterns to poorer cognitive performance and health. 

However, researchers also point out that the findings show an association - not a cause-and-effect relationship.

"From our study, we can't conclude that sleep irregularity results in health risks, or whether health conditions affect sleep," said Jessica Lunsford-Avery, Ph.D., an assistant professor in psychiatry and the study's lead author. "Perhaps all of these things are impacting each other." 

So while further research is needed to tease out the exact relationship between biology and sleep regularity, and the chances of me successfully implementing a consistent sleep-wake schedule for myself are close to zero, I'll certainly pop it on my future to-do-list - right under 'get more sleep'.