If you’re often sleepy during the day and frequently take a long afternoon snooze, you’re more likely to develop Type 2 diabetes, researchers from the University of Tokyo report.
Researchers presented their findings on September 18 at the 51st Annual Meeting of the European Association for the Study of Diabetes currently taking place in Stockholm, Sweden.
The team reviewed 10 studies including more than 260,000 people to find links between daytime sleepiness or napping and the risk of Type 2 diabetes. They found that individuals who reported feeling drowsy during the day had a 56% higher risk of adult-onset diabetes than those who didn’t. Those who reported taking naps for 60 minutes or more were found to have a 46% higher risk of having the disease than those who took no or smaller naps. [1]
No adverse link was found between short naps of 40 minutes a day and Type 2 diabetes.
While the findings point to an association between daytime sleepiness and napping and Type 2 diabetes, it doesn’t prove cause and effect. Researchers say the correlation may suggest the two conditions are simply early warning signs of the disease. So don’t worry too much about those naps yet.
Dr. Tomohide Yamada, a researcher at the department of diabetes and metabolic diseases at the University of Tokyo in Japan, said it’s also possible that unhealthy people, in general, are more likely to be tired and sleep during the day.
Other conditions, such as sleep apnea and depression, could also contribute to daytime drowsiness. Previous research shows both conditions may be contributing factors to Type 2 diabetes, and sleep apnea has been shown to increase the risk for ischemia, stroke, cardiovascular events, and all-cause mortality.
A 20- to 30-minute nap can lift your mood, make you more alert, improve your performance, and even ‘improve memory five-fold,’ but sleeping for longer than that can make you feel disoriented, the National Sleep Foundation says. Simply put, it can make you feel worse than you did before you took a nap. This can negatively impact the length and quality of nighttime sleep, which can harm your overall health. [3]
“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,” the researchers explain. “Although the mechanisms by which a short nap might decrease the risk of diabetes are still unclear, such duration-dependent differences in the effects of sleep might partly explain our findings.”
We’d say to take the findings with a grain of salt, and not place too much worry on your beloved naps.
Additional Sources:
[1] The Wall Street Journal
[2] Fox News
[3] Medical News Today