Sleep 'influences diabetes risk'

Burning the candle at both ends during the working week could raise a person's risk of developing type 2 diabetes, New York researchers say.

People who slept fewer than six hours a night were more likely to develop a condition that precedes diabetes than those sleeping for longer, they found.

They said the study supported mounting evidence that cutting back on sleep can have a profound impact on health.

The six-year study was presented at an American Heart Association conference.

Cases of type 2 diabetes, which are often, but not always, linked to obesity, have been rising across the globe.

The condition develops when the body makes too much insulin, but does not use the hormone efficiently to break down sugar in the blood.

A stepping stone on the way to the condition is known as impaired fasting glucose, in which blood sugar levels are too high, but not high enough to constitute a diagnosis of diabetes.

A team from the University of Buffalo, in New York, followed a group of volunteers over a six-year period.

They found those who slept on average for fewer than six hours a night during the working week were 4.56 times more likely to develop impaired fasting glucose than those sleeping six to eight hours a night.

Lead researcher Dr Lisa Rafalson said: "This study supports growing evidence of the association of inadequate sleep with adverse health issues."

Complex area
Dr Rafalson said it was likely that hormones and the nervous system were behind the link.

"Our findings will hopefully spur additional research into this very complex area of sleep and illness," she said.

A recent study suggested that taking regular lunchtime siestas could increase the risk of developing type 2 diabetes.

Dr Neil Stanley, a sleep expert at Norfolk and Norwich University Hospital, said there was a mounting body of evidence linking lack of sleep to conditions such as diabetes.

However, he said the reasons remained unclear, although it was possible that lack of sleep raised the risk of putting on weight, which in turn could raise the risk of diabetes.

"There is some evidence that lack of sleep mucks up our appetite hormones, so you want to eat more, and eat the wrong things - when we are tired we tend to crave sugary foods.

"A good night's sleep is a biological necessity: your body wants and needs a good night's sleep every night, and if you are well rested you will get a lot more done during the day."

Dr Iain Frame, director of research at the charity Diabetes UK, said the study was too small to draw any firm conclusions.

However, he said the findings echoed previous studies which found there might be a link between disturbed sleep patterns and a raised risk of type 2 diabetes.

But he added: "When it comes to discussing major risk factors for developing type 2 diabetes, issues with sleep duration will remain less significant than other established risk factors such as being overweight, being over the age of 40 or having a history of diabetes in the family."