Work-related stress and Type 2 diabetes: systematic review and meta-analysis.

BACKGROUND Work-related psychosocial stress has been hypothesized to increase the individual risk of Type 2 diabetes; however, observational epidemiological studies investigating the association between work-related psychosocial stress and Type 2 diabetes have provided an inconsistent picture. AIMS To evaluate whether work-related psychosocial stress (defined by a work-related stress model or by long work hours) is associated with the risk of Type 2 diabetes. METHODS A systematic review of the literature was conducted until March 2010. Studies eligible for inclusion were published observational epidemiological studies of adult participants in community or occupational settings if they had a measure of work-related stress on a validated scale or a measure of work hours or overtime assessed prior to, or at the same time as, assessment of Type 2 diabetes status. Where possible, meta-analysis was conducted to obtain summary odds ratios of the association. RESULTS We located nine studies (four prospective, one case-control and four cross-sectional). The meta-analyses did not show any statistically significant associations between any individual aspect of work-related psychosocial stress or job strain and risk of Type 2 diabetes. CONCLUSIONS The specific hypothesis that a working environment characterized by high psychosocial stress is directly associated with increased risk of Type 2 diabetes could not be supported from the meta-analysis.