Type 2 diabetes, once known as adult-onset or noninsulin-dependent diabetes, affects millions of Americans with an increasing number of diagnoses; in 2010, about 1.9 million new cases of diabetes were diagnosed in people aged 20 years or older. While the development of the disease is more commonly associated with risk factors such as obesity, high blood pressure, and physical inactivity, stress also has a significant impact, scientists believe.

Now Dr. Sharon Toker of Tel Aviv University has found that low levels of social support and high levels of stress in the workplace can accurately predict the development of diabetes over the long term.

Participants in the study were 5,843 men and women, all apparently healthy. Researchers recruited individuals from those who visited a health center in Tel Aviv for a routine physical examination sponsored by their employer. To assess whether physical and psychological strain caused by the work environment could predict the development of diabetes, lead author Dr. Toker and her fellow researchers surveyed the participants according to an "expanded job strain model," which takes into account measures of social support, perceived workload, and perceived control over work pace and objectives.

After the initial interview and examination, the health of all participants was followed for a period of 41 months, over which time 182 participants developed diabetes, reported Dr. Toker. When these results were analyzed in relation to reported work conditions, social support emerged as a strong protective factor against the development of the disease, with supported individuals significantly less at risk for diabetes than their unsupported peers. In fact, participants who reported having a high level of social support at work had a 22 percent lesser chance of developing diabetes over the course of the study.

Yet, workload was also correlated with disease development, with employees who felt either overworked or underworked being at increased risk; those who described themselves as either over- or under-worked were 18 percent more likely to develop the disease.

"You don't want to see working populations have an increasing rate of diabetes. It's costly to both employees and employers, resulting in absenteeism and triggering expensive medical insurance," said Dr. Toker who explained that her findings showed a worrying rise in the rate of diabetes in the middle-aged cohort, which had a mean age of 48.

Employees are putting in more hours than ever before while technology allows for constant connection, which often increases workloads. Yet another finding of the study - that a too-small workload is as harmful as a too-large workload - thwarts the expectation that dramatically reducing the load of a busy employee might shift health outcomes in a positive direction. The results highlight some of the negative effects of our changing work environment, said Dr. Toker.

Toker S, Shirom A, Melamed S, Armon G. Work characteristics as predictors of diabetes incidence among apparently healthy employees. Journal of Occupational Health Psychology. Jul 2012; 17:3. http://psycnet.apa.org/index.cfm?fa=search.displayRecord&id=8F12D4DA-A6B3-3698-2604-8C30769F0FBA&resultID=1&page=1&dbTab=pa. Accessed May 10, 2013.