Women who work at least 45 hours per week may have a higher risk for developing type 2 diabetes vs. women working between 35 and 40 hours per week, according to a study published in BMJ Open Diabetes Research & Care.
“Considering the rapid and substantial increase of diabetes prevalence, identifying modifiable risk factors is of major importance,” Mahée Gilbert-Ouimet, PhD, postdoctoral fellow at the Institute for Work and Health, University of Toronto, told Endocrine Today. “In this regard, long work hours have recently been linked with diabetes, but more high-quality prospective studies were needed.”
In order to evaluate the relationship between long work hours and the incidence of diabetes, researchers examined data from respondents to the 2003 Canadian Community Health Survey, which collects information on health conditions, health behaviors and working conditions from representative cross-sectional samples of the Canadian population. Researchers identified a sample of 7,065 individuals with no previous diabetes diagnosis who were employed and worked at least 15 hours per week (3,502 women; 3,563 men; aged 35 to 74 years). The sample was further divided into categories based on workweek length: 15 to 34 hours, 35 to 40 hours, 41 to 44 hours and 45 or more hours per week. Working conditions, job skills needed, body movement required, BMI and health behaviors (smoking, alcohol consumption and time spent on physical activity) were also accounted for.
Researchers then used Cox proportional hazard regression models, conducted separately for men and women, to examine the association between long work hours and the incidence of diabetes during the 12-year follow-up (median length of follow-up, 11.7 years). One model looked at the effect of long work hours on diabetes after adjusting for age, weeks worked in the previous year and skill level, whereas another model included additional adjustments for all other covariates, except health behaviors and BMI. A third model adjusted for health behaviors and the fourth adjusted for BMI.
During the study period, 12.2% of men and 7.5% of women developed diabetes.
Researchers found that women working 45 hours or more per week had a 63% higher risk for developing diabetes vs. women working between 35 and 40 hours per week (HR = 1.63; 95% CI, 1.04-2.57). For men, the incidence of diabetes tended to diminish as work hours increased.
Gilbert-Ouimet said this study was not able to explicate the reasons behind longer workweeks contributing to diabetes in women but not in men.
“However, it is plausible that women work longer hours when all the household chores and family responsibilities are taken into account,” she said. “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.”
In practice, Gilbert-Ouimet said clinicians should ask how many hours per week their female patients are currently working as part of their screening routines for type 2 diabetes.
“Promoting the regular workweek of 35 to 40 hours might be an effective strategy for preventing diabetes among women,” she said. – by Melissa J. Webb
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Mahée Gilbert-Ouimet, PhD, can be reached at email@example.com.
Disclosures: The authors report no relevant financial disclosures.