Women who work 45 hours or more each week could be more likely to develop diabetes, a Canadian study suggests.
Researchers tracked 7,065 workers aged 35 and older in Ontario, Canada, over 12 years. None of them had diabetes at the start of the study or during the first two years of follow-up.
About 8 percent of the women and 12 percent of the men did develop diabetes by the end of the study period.
Work hours didn’t appear to influence the risk of diabetes for men. But women working at least 45 hours a week were 63 percent more likely to develop diabetes than women working 35 to 40 hours weekly.
“Our study did not allow us to explain the gender differences,” said lead author Mahee Gilbert-Ouimet, a researcher at the Institute for Work & Health of Toronto.
“However, it is plausible that women work longer hours, when all the household chores and family responsibilities are taken into account,” Gilbert-Ouimet said by email. “For their part, men performing long work hours tend to hold more physically active jobs than women, get an important sense of identity through work and are more likely to hold high-skilled and well-paid occupations.”
Working more hours on the job and at home might make women more prone to chronic stress, inflammation and hormonal changes that could potentially contribute to diabetes, researchers note in BMJ Open Diabetes Research & Care.
Worldwide, nearly one in 10 adults had diabetes in 2014, and the disease will be the seventh leading cause of death by 2030, according to the World Health Organization.
Most of these people have type 2 diabetes, which is associated with obesity and aging and happens when the body can’t properly use or make enough of the hormone insulin to convert blood sugar into energy. Left untreated, diabetes can lead to nerve damage, amputations, blindness, heart disease and strokes.
Physicians have long recommended exercise, weight loss and a healthy diet to control blood pressure and minimize other complications of the disease. Stress reduction is also advised because, whether it’s caused on the job or not, stress may also make diabetes worse by directly contributing to a spike in blood sugar or by leading to unhealthy lifestyle habits that can cause complications.
Previous research has linked stress on the job and long work hours to an increased diabetes risk, but most of these studies have focused on men, the authors of the current study note.
For their analysis, the researchers examined data on participants’ total paid and unpaid work hours. They also accounted for other factors that might independently influence the risk of diabetes including lifestyle habits and chronic medical issues.
One limitation of the results is that researchers only assessed work hours once, and changes over time might influence the risk of diabetes, the authors acknowledge.
Even so, the findings add to evidence that ties long work hours to diabetes, said Dr. Rita Hamad, a researcher at the University of California, San Francisco who wasn’t involved in the study.
“People who work longer hours may have less time to take care of themselves by eating healthy and exercising,” Hamad said by email. “They may also be more stressed and get less sleep - all of these things might make someone more likely to get diabetes.”
While more research is needed to determine exactly why long hours or stressful work might lead to diabetes, people can still make some changes to try to minimize their risk, said Daniel Lackland, a researcher at the Medical University of South Carolina in Charleston who wasn’t involved in the study.
“Shorter bouts of work and shifts might be assessed,” Lackland said by email. “Exercise breaks, or getting lots of activity outside work, or other lifestyle decisions like eating well or avoiding smoking might potentially help.