Daytime naps 'may increase risk of developing type 2 diabetes'

Taking a long nap during the day or being exceptionally tired raises the risk of developing type 2 diabetes, research has found.

Scientists from the University of Tokyo found that “excessive daytime sleepiness” was linked to a 56 per cent increased risk of getting diabetes.

Examining data from 261,000 participants in more than 200 studies also found that taking a regular daytime nap for upwards of one hour was found to raise the risk of developing the condition by 46 per cent.

But researchers are unclear as to whether taking a nap or an underlying condition that causes sleepiness is the accelerant.

Dr Tomohide Yamada, author of the study, said: “Excessive daytime sleepiness and taking longer naps were associated with increased risk of type 2 diabetes, with a short nap not increasing this risk.

“Daytime napping might be a consequence of night-time sleep disturbance such as obstructive sleep apnoea.

“Epidemiological studies have shown that obstructive sleep apnoea is independently linked to blockages (ischaemia) of heart arteries, stroke, fatal and non-fatal cardiovascular events, and all-cause mortality.”

The research was presented to the annual meeting of the European Association for the Study of Diabetes.