Working lots of overtime hours may increase the risk of Type 2 diabetes in women, research shows. The study suggests that women who work more than 45 hours a week have a greater risk of the disease than women who work 30-40 hours a week. 
The questions researchers couldn’t answer in the study were why working overtime increases the risk of diabetes, or why this link was found only in women. The scientists theorize that the answer to both questions might have something to do with the hours of unpaid work that women are more likely to engage in than men.
Lead study author Peter Smith, a senior scientist at the Institute for Work and Health in Toronto, Canada, said:
“It’s important to understand that the work environment does play an increased role in the risk of Type 2 diabetes and other chronic diseases. Working long hours is not a healthy thing to do.”
“If you look at time spent outside of work, women do more care of household members and more routine housework. The only thing women don’t do more of it watching TV and exercising.”
In the study, Smith and his fellow researchers analyzed data from a database of more than 7,000 workers in Canada and followed them for more than 12 years to determine whether work hours can affect the risk of diabetes.
Get this: the scientists found that 1 in 10 people in the study developed diabetes, especially men who were older and obese. Overall, women were less likely to develop diabetes … unless they worked more than 45 hours a week. They found that women who worked more than 45 hours a week had a 51% greater risk of diabetes compared to women working 30-40 hours.
The finding remained solid after researchers adjusted for other factors that can increase diabetes risk, including physical activity, smoking, and body mass index (BMI).
Men who worked overtime, on the other hand, actually had a lower risk of diabetes when compared to men who worked a more normal work week.
Mahee Gilbert-Ouimet, an epidemiologist and postdoctoral fellow at the Institute for Work and Health in Toronto, commented:
“I was to see the somewhat protective effect of longer working hours among men. Among women, we know women tend to assume a lot of family chores and responsibilities outside the workplace, so one can assume that working long hours on top of that can have an adverse effect on health.”
For instance, the study found that women were significantly more affected when they worked more than 45 hours a week and lived with a child under the age of 12.
Another possibility as to why women suffer from working long hours more than men is that in the study, about 1/3 of the men who worked overtime said they spent those work hours doing a combination of sitting, standing, and walking. Only about 8% of women reported getting as much physical activity on the job.
And it’s important to point out that people who work more than 40 hours a week – regardless of gender – experience higher levels of stress, which can alter hormone levels, like cortisol. Changes in cortisol can affect the body’s insulin levels and its ability to break down sugar.
Moreover, having a lot of stress in your life can cause sleep problems and mental health problems, both of which can lead to changes in weight and insulin levels. All of these consequences of stress increase the risk of diabetes overall.
Gilbert-Ouimet said he hopes the findings will encourage doctors to talk to their patients about the link between too much time spent working and diabetes – especially women.
“I think physicians should ask the question of how many hours a week their patients work. And if women also have risk factors, them they should discuss more follow-up visits or screening tests for diabetes.”