Long daytime naps linked to type-2 diabetes

A study carried out by the University of Tokyo has found that napping for more than an hour per day could be a warning sign for type-2 diabetes.

The research analysed observational studies involving more than 300,000 people. The findings suggested a link between long daytime naps of more than 60 minutes and a 45 per cent increased risk of type-2 diabetes, compared with no daytime napping - however there was no link with naps of less than 40 minutes.

The researchers maintained that taking long naps during the day could be a result of disturbed sleep at night, potentially cause by sleep apnoea. They added that this particular sleeping disorder could increase the risk of heart attacks, stroke, cardiovascular problems and other metabolic disorders, including type-2 diabetes.

Among other factors, the study identified that sleep deprivation, which could be caused by work or social life patterns, could also lead to an increased appetite and an increase in the risk of type-2 diabetes.

In contrast, the study outlined that shorter naps were more likely to increase alertness and motor skills.

Naveed Sattar, professor of metabolic medicine at the University of Glasgow, said: “It's likely that risk factors which lead to diabetes also cause napping. This could include slightly high sugar levels, meaning napping may be an early warning sign of diabetes.”

However, Sattar maintained that more detailed trials were needed to determine whether sleeping patterns make a real difference to ‘health outcomes’.