Working continuously in rotating day and night shifts over a long period of time increases the risk of type 2 diabetes in women, a new study published in the journal PLoS One reveals.
Researchers at Harvard School of Public Health used data from the Nurses' Health Study I and II carried out between 1988 and 2008 and involved more than 177,000 women. In total around 60 percent of the nurses had served at least one year of rotating night shift work while 11 percent from Study I and 4 percent from Study II had served at least 10 years.
The researchers found that those who had worked on rotating night shifts for three to nine years had a 20 percent greater risk of developing type 2 diabetes. The risk increased to 40 percent among nurses who had spent 10 to 19 years working at nights and 58 percent among nurses who had worked at nights for more than 20 years.
"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", lead researcher Frank Hu said.