Demanding work could put a woman at a higher risk for type 2 diabetes, according to a new study.
Among a cohort of French women, those who said their work was “very mentally tiring” — a proxy measure for job demands — had a 21% (95% CI 1.09-1.35) higher risk for type 2 diabetes compared with women who said their work was “little or not mentally tiring,” found Guy Fagherazzi, PhD, of the Center for Research in Epidemiology and Population Health at Paris-Saclay University in France, and colleagues.
Interestingly, this association was only significant among women without overweight or obesity and a BMI under 25, the group wrote in the European Journal of Endocrinology.
This relationship — being restricted to non-overweight women — hasn’t been previous reported, Fagherazzi and co-authors stated, adding that the association “could be explained by the fact that in overweight/obese individuals, the relative importance of adiposity on the risk of type 2 diabetes is so strong that it could mask the potential association between mentally-tiring work and type 2 diabetes.”
The analysis included data on over 73,500 women from France in the E3N prospective cohort study, most of whom worked as teachers as employees of the French National Education system. All women were born from 1925 through 1950, with a 22-year follow-up period beginning in 1992. Information on the level of mentally tiring work was collected via questionnaire and categorized into three levels: little or not mentally tiring, mentally tiring, or very tiring.
During follow-up, there were nearly 4,200 validated incident cases of type 2 diabetes reported. When assessing the diabetes risk relationship with work-related psychological demands, the researchers adjusted the model for several type 2 diabetes risk factors including education level, most recent profession, level of recreational physical activity, smoking status, body mass index, hypertension, family history of diabetes, and use of cholesterol-lowering medication.
Among the 24% of women in the study who said their work was very mentally tiring, they were more likely to have a family history of diabetes compared with women who said their work was not mentally tiring.
The women with mentally tiring jobs were also more likely to have these other baseline characteristics versus women without mentally tiring jobs, the results showed:
- Be overweight: 20.7% vs 18.0%
- Less likely to be smokers: 13.7% vs 15.1%
- Use cholesterol-lowering drugs: 7.0% vs 5.6%
- More years of education: 14.16 years vs 13.52 years
- Be teachers with the French Ministry of Education: 90.9% vs 43.0%
Two main mechanisms likely explain this diabetes-work stress relationship, the group wrote. One possible mechanism relates to the activation of the hypothalamus-pituitary-adrenal axis and the sympathetic nervous system from work stress elevating cortisol levels, leading to more glucose output, less insulin secretion, and insulin resistance.
“The second potential mechanism is that people who work with high job strain or job demands tend to more frequently exhibit unhealthy lifestyle factors — such as poor sleep, smoking, unhealthy dietary patterns — that are frequently related to a higher risk of type 2 diabetes,” the researchers explained, noting, however, that prior research points to this explanation as not being quite as likely.
As for this study being exclusive to women, Fagherazzi’s group said that traditional gender roles also don’t help to protect women against diabetes risk: “As women still spend more time than men on household tasks and childcare, this could result in less time to relax and therefore enhance the detrimental effect of a demanding job. A more direct biological effect can be hypothesized as well, as women could respond more intensely to work-related stress than men by having higher cortisol levels during working days,” the team suggested.
Despite the study’s strength of a 22-year follow-up period, it was also limited by the cohort’s lack of diversity, as it was comprised of “rather homogenous health-conscious women,” the researchers said.
Fagherazzi and co-authors reported having no conflicts of interest to disclose.