Night shift work a risk factor for diabetes?

The more years black women spend working the night shift, the higher their risk for developing diabetes, according to a new study in Diabetologia.

Using data from the Black Women's Health Study, researchers tracked the development of the disease over eight years. Of more than 28,000 participants, 37% worked the night shift.

Those who had worked overnight for one to two years had a 17% percent greater chance of developing diabetes. The risk jumped to 23% for those with three to nine years of shift work, and to 42% for women with 10-plus years. The risk was more pronounced in women under 50.

Even after adjusting for body mass index and lifestyle factors such as diet and smoking, researchers said they still found a 12% increased risk for night workers.

Researchers, led by Varsha Vimalananda, M.D., of the Center for Health Organization and Implementation Research, said they believe disrupted circadian rhythms may play a causal role.

“Shift workers experience fatigue, sleepiness during scheduled awake periods and poor sleep,” they write. “These alterations … have profound effects on metabolism.”