Deployment to a combat environment is associated with a marked increase in new-onset fibromyalgia, which shows a bidirectional relationship with post-traumatic stress disorder (PTSD), according to study results published in Arthritis Care & Research.
Traumatic life events have long been hypothesized as triggers for fibromyalgia, with PTSD as a well-recognized comorbidity. However, prospective data collected both before and after high-magnitude stress exposures have been limited.
To address this knowledge gap, researchers conducted a longitudinal cohort study involving 1761 active-duty United States military service members (91.3% men; 57.8% White). Assessments took place before and after combat deployments between 2010 and 2016 that lasted approximately 12 months.
Probable fibromyalgia was identified using the 2010 American College of Rheumatology questionnaire criteria, which incorporated the widespread pain index and symptom severity scores. Probable PTSD was assessed using the PTSD Checklist Stressor-Specific Version with established symptom and severity thresholds. Combat-related stressor exposure data were obtained from Defense Medical Surveillance System records
The bidirectional comorbidity between fibromyalgia and PTSD suggests a potential link in the central nervous system and has implications for management.
A total of 1630 participants had sufficient combat-related stressor data. Fibromyalgia prevalence before deployment was 2.2% among men and 2.0% among women, similar to civilian estimates. After deployment, prevalence increased significantly to 8.0% among men and 11.1% among women (P <.001), corresponding to 3.6-fold and 5.6-fold increases, respectively.
Predeployment PTSD prevalence was 20.7% among men and 18.3% among women, which rose to 22.7% and 25.5% after deployment, respectively; these increases were not statistically significant. Overall, 38.4% of participants reported at least 1 major combat-related stressor.
Service members with predeployment PTSD were 2.96 times more likely to develop fibromyalgia after deployment (95% CI, 2.08-4.22). Conversely, those with predeployment fibromyalgia were 3.12 times more likely to develop PTSD after deployment (95% CI, 1.63-5.95). These relationships remained strong even after excluding individuals with baseline fibromyalgia or PTSD.
Study limitations include reliance on validated self-report questionnaires for fibromyalgia/PTSD diagnoses and a lack of data on the degree of trauma exposure.
“The bidirectional comorbidity between fibromyalgia and PTSD suggests a potential link in the central nervous system and has implications for management,” the study authors concluded.
