Women who work 45 hours or more each week may be upping their risk of diabetes, new research finds. Men who work the same number of hours, however, are not affected.

While prior research has suggested a link between a long work week and an increased risk of diabetes, most of these studies focused on men.

Interestingly, this recent research seems to find the opposite effect in males: the longer the work week, the lower the incidence of diabetes.

For women who work 45 hours per week or more, though, their risk was considerably higher.

When compared with women who work 35–40 hours each week, they had a 63% higher risk of developing diabetes.

The authors of the new study, which was published in BMJ Open Diabetes Research and Care, looked at data from the 2003 Canadian Community Health survey, which included respondents aged 35–74.

They also looked at the Ontario Health Insurance Plan database for physician services, as well as the Canadian Institute for Health Information Discharge Abstract Database for hospital admissions.

In all, over 7,000 Canadian employees were included in the research. As well as looking at hours worked, the researchers also included other factors in their analysis, such as sex, marital status, parenthood, ethnicity, place of birth, place of residence, long-term health conditions, lifestyle, weight, and BMI.

They also considered unique workplace factors, such as shift work and the type of job the respondents did—for instance, whether it was predominantly active or sedentary.

Overall, the risk of diabetes was "only slightly reduced" when factors such as smoking and alcohol levels were considered.

While the researchers could not establish a definitive cause and effect from these data, they note that encouraging women to work fewer hours may be a key component of reducing the number of diabetes cases.

The shape of diabetes

Diabetes is a widespread issue around the world and impacts many lives. When someone has diabetes, their body does not utilize insulin properly; the pancreas increases production of the hormone until it can no longer keep up with the body's demands.

This leads to higher-than-normal blood glucose levels and can eventually cause a wide range of problems throughout the body.

The American Diabetes Association say that over 30 million people in the United States have diabetes, and 7 million of these individuals are unaware of it.

Diabetes remains the seventh leading cause of death in the US, and, each year, doctors discover 1.5 million new cases. Worldwide, this number jumps to 425 million adults, with half remaining undiagnosed.

Diabetes prevention and management, then, are an essential facet of public health. Studies such as this one can help doctors to create guidelines that can positively impact the health of their patients and lead to fewer cases of diabetes down the road.

Limitations and next steps

Although the records used in this study did not distinguish between type 1 and type 2 diabetes, it is estimated that type 1 diabetes accounts for around 5% of cases among those aged 18 or over, so most of these cases were likely to be type 2.

In the future, if further studies agree with these findings, health-care providers may recommend that women work 40 hours per week or under.

The study authors write, "Considering the rapid and substantial increase of diabetes prevalence in Canada and worldwide, identifying modifiable risk factors, such as long work hours, is of major importance to improve prevention and orient policy making, as it could prevent numerous cases of diabetes and diabetes-related chronic diseases."