By Samantha Semoso – EMTV Online
Research presented at the 51st annual meeting of the European Association for the Study of Diabetes, taking place in Stockholm, Sweden, found that excessive daytime sleepiness and long naps can signal many things, from working late to sleep disturbance.
According to a new study, however, daytime sleepiness and taking long naps may both also be associated with an increased risk of type 2 diabetes.
Getting enough sleep is a key part of a healthy lifestyle, playing a crucial role in protecting both physical and mental health. Not getting enough sleep can lead to sleepiness during the day along with napping – the habit of taking short sleeps ranging from a few minutes to a few hours.
According to the National Sleep Foundation, a short nap of 20-30 minutes can help improve mood, alertness and performance. However, napping for longer than 10-20 minutes can lead to sleep inertia – a feeling of disorientation that comes from waking after a deep sleep – as well as potentially having a negative effect on the length and quality of night time sleep.
The researchers identified 10 studies that were suitable for the meta-analysis, involving a total of 261,365 subjects. These studies utilised self-reporting to determine daytime sleepiness and napping, with questions such as “Do you have a problem with sleepiness during daytime?” to measure participants sleep habits.
Risk of type 2 diabetes increased by 56 per cent among those who reported excessive daytime sleepiness. While napping for longer than 60 minutes during the day increased the risk of type 2 diabetes by 46 per cent, naps that were shorter than this not affect diabetes risk.
“Excessive daytime sleepiness and taking longer naps were associated with increased risk of type 2 diabetes, with a short nap not increasing this risk,” the authors concluded.
They suggest that mechanisms behind short naps – demonstrated in several studies to have beneficial effects – could explain things, stating that short naps finish before the onset of deep slow-wave sleep:
“Entering deep slow-wave sleep and then failing to complete the normal sleep cycle can result in a phenomenon known as sleep inertia, in which a person feels groggy, disoriented, and even sleepier than before napping. Although the mechanisms by which a short nap might decrease the risk of diabetes are still unclear, such as duration-dependent differences in the effects of sleep might partly explain our findings.”
The researchers also point out that daytime napping could be caused by night-time sleep disturbances such as obstructive sleep apnea. This condition is associated with ischemia, stroke, cardiovascular events and all-cause mortality, and also shares some risk factors with type 2 diabetes, such as excess weight and age.