A study from the University of Cambridge has found strong correlations between duration of sleep and risk of stroke. It is well understood that a lack of sleep can have profound effects on your quality of life, a lack of sleep can leave people feeling anxious, stressed and irritable in the short term, and chronically fatigued and reduced ability to concentrate in the long term. In the same note though, many of you will have woken up after a good, solid 10 hour sleep to find that you feel a little sluggish because of the extended time in the sack, so it goes both ways.
What the study found
Researchers found that short sleep was associated with an 18% increased risk of stroke, whereas long bouts of sleep was linked to a 46% increase risk of stroke. The researchers apparently adjusted for those people at a greater risk of stroke due to underlying heart disease and other comorbidities, which increases the validity of the study. On top of this, those subjects who had long durations of sleep were almost twice as likely to suffer from a stroke compared to those with persistently average sleep duration. A very concerning finding (note I don’t say ‘fact’, this is just a single finding) was that those people whose sleep duration increased dramatically over the course of a 4 year period had approximately 4x more likelihood of having a stroke!
Meta- analysis showed similar findings
A finding that went some way to substantiating this studies results was a meta- analysis on sleep duration and stroke. A meta- analysis is very important because it is a consensus of research findings taken from all robust and peer reviewed journals on a particular subject area. A meta- analysis comes with a lot of validity, and this particular analysis found very similar findings as the Cambridge study.
Lead author Yue Leng explains:
"We believe long sleep duration is an indicator of increased stroke risk. We are not suggesting that sleep causes the increased risk, but it could be a useful marker of other underlying conditions that do increase stroke risk,"
Medscape, (2015) states that Mr Leng went on to say:
"By asking one question about how many hours a patient sleeps and whether this has changed in recent years, doctors could ascertain information about that patient's risk of stroke,"
These findings, although they don’t mean this is 100%, categorically the case, go some way to explaining the potential risk of too much sleep. Too much of anything isn’t usually a good thing, and it seems that too much sleep could also be detrimental to health. Like with most things in life, try to get the balance, aim for between 7-8 hours a night for optimal health. Check this previous article on the subject. Just to add a little more confusion to the matter, the findings from this particular study concluded that less than 6 hours sleep a night (consistently) can increase the risk of stroke by 4 times! So do your best to regulate your sleep by shooting for 7-8 hours every night, of course the odd late night isn’t going to hurt, but you get the message.
Medscape, (2015). Long Sleep Duration May Signal Increased Stroke Risk. Retrieved 4th March, 2015, from http://www.medscape.com/viewarticle/840591