Type 2 Diabetes: Stressed Women Who Are 'Mentally Tired' at Increased Risk, Scientists Believe

Women with jobs that are mentally tiring could be at a greater risk of developing type 2 diabetes, scientists warned.

The authors of a study published in the European Journal of Endocrinology evaluated data from 73,517 French women to find out whether stress was associated with developing the disease. The women's health was tracked over a 22-year period, between 1992 and 2014. The participants, most of whom were teachers, filled in questionnaires about their health biennially. In that time, 4,187 were diagnosed with type 2 diabetes.

In a 1992 questionnaire, women were asked whether they found their work mentally tiring, and could answer: "Little or not mentally tiring," "Mentally tiring" or "Very mentally tiring." Women who engaged in "very mentally tiring work" were found to be more prone to type 2 diabetes, even when other factors—including lifestyle choices—were taken into account.

Of the total, 24 percent said they had very mentally tiring work. Overall, women who had very mentally tiring jobs were at 21 percent higher risk of developing type 2 diabetes compared with the others. This association was mainly found in those with a healthy body weight, or "non-overweight." Women in the "very" group were also more likely to have diabetes in their family compared with others, and were more likely to be overweight, smoke and take drugs to regulate their cholesterol.

The authors wrote: "These observational results suggest the importance of taking into consideration the potential long-term metabolic impact of work-related stress for women working in a demanding environment."

It wasn't clear what led to the association. Stress, the authors argued, could activate the sympathetic nervous system, which is in charge of the body's fight or flight response, and the hypothalamus–pituitary–adrenal axis, which is influenced by stress and plays a role in keeping the body's functions under control. This, in turn, could affect how the body creates insulin and processes glucose. Or, those with high-pressure jobs could have unhealthier behaviors that are tied to diabetes, such as poor sleep and diet, and smoking.

The study came off the back of a separate meta-analysis by another team. That study, which involved both men and women, found no overall link between stress and diabetes. However, stressed-out women were found to be more vulnerable to the disease than men. This could be because women are more likely burdened with domestic duties on top of their obligations at work, the authors of the new study said, adding that they wanted to investigate further.

Detailing the potential limitations of the study, the researchers said they were not aware if the women were prescribed drugs or self-medicated to deal with stress, and the participants were "rather homogenous health-conscious women." The study was observational, so lacked the strength of a random sampling controlled study.

Guy Fagherazzi of the Center for Research in Epidemiology and Population Health at Inserm, said in a statement: "Both mentally tiring work and type 2 diabetes are increasingly prevalent phenomena.

"Therefore, our results can have substantial implications regarding both the understanding of the underlying mechanisms and the prevention of adverse effects of work-related stress. It is known that, in contrast to men, both intellectual and emotional demands determine occupational stress in women and that support in the workplace has a stronger impact on work-related stress in women than men.

"Consequently, an increase in the support of women in demanding work environments could be a tool for type 2 diabetes prevention."

He continued: "The next step for our research is to investigate, in individuals living with diabetes, how stress and anxiety, including work-related stress, can have an impact on diabetes management, quality of life and the risk of diabetes-related complications."

Dr. Robert A. Gabbay is a chief medical officer at the Joslin Diabetes Center and associate professor of medicine at Harvard Medical School who was not involved in the research. He told Newsweek this was an association study, so "no cause or effect can be determined and could be a statistical fluke. It is hypothesis generating."

Faye Riley, research communications officer at the charity Diabetes U.K., who was not involved in the research, told Newsweek: "Type 2 diabetes is a complex condition with a range of factors influencing an individual's risk. Equally, everyone experiences, perceives and defines stress differently. While this research does suggest a potential relationship between work-related stress and an increased risk of Type 2 diabetes, it does not show that stress directly influences risk.

"We need to know more about this potential relationship, and what could underpin it; understanding the interplay between stress and risk of Type 2 diabetes in more detail could help us determine whether support for women who work in stressful environments could help to prevent Type 2 diabetes, for example. In the meantime, the best way to reduce your risk of Type 2 diabetes is through maintaining a healthy weight, exercising regularly and quitting smoking."

Last year, a separate study indicated working at least 45 hours a week could raise the risk of a woman developing the disease, which 1.5 million Americans are diagnosed with each year.

The study published in the journal BMJ Open Diabetes Research and Care involved more than 7,000 Canadian workers between the ages of 35 and 74, who were evaluated between 2003 and 2015.

At the time, Dan Howarth, the head of care at the charity Diabetes U.K., told Newsweek: "This large, long-term observational study adds to the body of evidence which shows that working long hours can have a negative impact on our health."