The study adds to a growing number of reports suggesting that overwork negatively affects well-being. Based on an analysis of 7,065 workers over a 12-year period, researchers in Canada observed that women who usually work more than 45 hours per week had a 63 percent higher incidence of diabetes than women working between 35 and 40 hours per week. The result takes into account mediating factors such as smoking, leisure time, physical activity, alcohol consumption, and body mass index. The study notes that the Ontario Health Insurance Plan (OHIP) database, one of the data sets used in the analysis, does not distinguish between type 1 and type 2 diabetes. But this heightened risk was not observed among men. “The risk increase among women isn’t trivial,” says one of the study’s authors, Cameron Mustard, PhD, an epidemiologist and senior scientist at the Institute for Work and Health in Toronto. “The question is why this elevated risk was not present for men, who have a higher incidence for the disease in general.” In fact, the study found that the incidence of diabetes in men tended to decrease as their number of work hours increased.
Women May Have Less Time for Healthy Habits
The research could not explain the imbalance between men and women. Dr. Mustard speculates that women who have more domestic responsibilities than men may have fewer hours to devote to physical exercise and nutrition. He underscores that high body weight and low physical activity are two modifiable risk factors that are strongly associated with the onset of diabetes. Individuals who are super busy may not have time to address those issues. Minisha Sood, MD, an endocrinologist at Lenox Hill Hospital in New York City, adds that hardworking women may have higher stress levels, which can play a role in diabetes. “Women who work long hours still carry much of the household responsibility outside of work, which may increase stress levels and decrease the hours during which they may otherwise focus on healthy meal preparation, exercise, proper sleep, and stress reduction,” says Dr. Sood, who was not involved in the study. “Stress management is a critical factor in overall well-being, and increased levels of stress hormones are metabolically disadvantageous.”
The Search to Curb a Chronic Disease
Mustard notes that research like this may help combat a potentially life-threatening condition that affects a growing number of people every year. “While heart disease is a chronic condition that has actually been on a steady decline, diabetes is one of the few chronic conditions in North America that we’ve seen rising over the last 20 years,” he says. As of 2015, 30.3 million Americans, or almost 10 percent of the U.S. population, live with diabetes. Another 84.1 million people have prediabetes, a condition that untreated often leads to type 2 diabetes within five years, according to the Centers for Disease Control and Prevention (CDC). Serious health complications from diabetes include premature death, vision loss, heart disease, stroke, kidney failure, and amputation of toes, feet, or legs. The disease can be managed through exercise, diet, and the proper use of insulin and other medications that maintain blood sugar levels.
More Research Is Needed
The new study’s authors emphasize that their investigation was observational and did not demonstrate that excessive work causes diabetes. Sood points out that results were determined from participants’ self-submitted surveys and medical records. “Furthermore, work hours were measured at a single point in time in the 12-year follow-up, so possible changes in work hours are not known in that period,” she says. She also notes that the study may have underestimated the number of people who had prediabetes before the investigation began. “We know that prediabetes remains largely undiagnosed in the population, and these participants would have been at higher risk of developing diabetes,” says Sood. “The reporting of diabetes relied on a diagnosis of diabetes in healthcare records, which unfortunately can be poor at capturing a patient’s true medical diagnosis.” Mustard advises women who work more than 45 hours a week, especially those who may be overweight or not very physically active, to get a checkup from a healthcare professional.
