All you ladies out there now have an excuse for getting out of working night shifts. A new study indicates women who work these hours could be increasing their risk of developing type 2 diabetes. Who knew?

Data from almost 200,000 female nurses over two decades found this risk to increase between 5 and 58 percent among those who worked the night shift at least three times a month, depending on how long they'd done so.

Much of the increase can be explained by weight gain, and working odd hours can make a healthier lifestyle more challenging.

Doctors also wonder whether disturbing our natural body clocks plays a factor as well. Previous studies have shown that sleep deprivation and irregular sleep-wake cycles can lead to insulin resistance and rising blood-sugar levels, classic hallmarks of diabetes.

Senior author Frank Hu, MD, a professor of nutrition and epidemiology at the Harvard School of Public Health, in Boston, said, “The increased risk is not huge, but it’s substantial and can have important public health implications given that almost one-fifth of the workforce is on some kind of rotating night shift."

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