Work stress and incidence of newly diagnosed fibromyalgia

Abstract

Objectives

We examined the prospective association between occupational stress and incidence of newly diagnosed fibromyalgia.

Methods

Cohort study with questionnaire surveys in 1998 and 2000 completed by 4791 hospital employees (4250 women and 541 men). Stress, as indicated by high workload, low decision latitude, and being a victim of workplace bullying, was assessed in the first survey. Incident cases (n=47) were employees reporting physician-diagnosed fibromyalgia in 2000 but not in 1998. Covariates were sex, age, income, obesity, and smoking.

Results

After adjustment for covariates, the odds ratio of incident diagnosed fibromyalgia for workplace bullying was 4.1 (95% CI 2.0–9.6). The corresponding odds ratios for high workload and low decision latitude were 2.1 (1.2–3.9) and 2.1 (1.1–4.0), respectively.

Conclusion

Stress seems to be a contributing factor in the development of fibromyalgia, but further research is needed to examine whether stress perceptions are affected by undiagnosed fibromyalgia.

Introduction

Fibromyalgia is a functional somatic syndrome, which cannot be explained in terms of a conventionally defined medical disease. It is characterized by widespread muscle pain, tenderness, fatigue, and sleep disturbances [1], [2], [3]. Although the aetiology of fibromyalgia is not well understood, stress has been hypothesized to be one of the provoking factors for this syndrome [4], [5], [6].

Prior studies have reported cross-sectional associations among life stress, emotional trauma, and fibromyalgia [6]. Retrospective and prospective studies suggest that stress and psychosocial factors are predictive of major symptoms of fibromyalgia, such as chronic widespread body pain [7], [8], [9] and chronic fatigue [10], [11], [12]. However, no prospective evidence is available to confirm that stress actually precedes the onset of fibromyalgia.

The present paper reports a prospective study to examine the association between stress and incidence of newly diagnosed fibromyalgia in a working population. High workload and low decision latitude at work are common sources of chronic stress and health problems among employees [13], [14], [15]. In addition to these two work stressors, we studied workplace bullying, a situation in which someone is subjected to social isolation or exclusion, his or her work and efforts are devaluated and he or she is threatened or otherwise worn down or frustrated. Exposure to workplace bullying has been shown to be a strong predictor of subsequent stress-related health problems, such as increased sickness absenteeism and clinical depression [16], [17]. To test the specificity of the association between work stress and fibromyalgia, we also examined the contribution of work stressors to other musculoskeletal disorders.