Exploratory Analysis of Respiratory Variability in Relation to Disease Impact, Affective Symptoms, and Pain Sensitivity in Fibromyalgia

PURPOSE: Fibromyalgia is a complex multisystem disorder characterized by generalized chronic pain. While its etiology remains largely unclear, neuroinflammation, chronic stress, and autonomic dysregulation may play significant roles. Resultantly, respiratory patterns could serve as both a biomarker and a therapeutic target in fibromyalgia. We hypothesized that fibromyalgia impact, anxiety, depression, pain intensity, and pain sensitivity are associated with reduced respiratory variability.

PATIENTS AND METHODS: In this observational study, twenty-three female participants with fibromyalgia completed the Revised Fibromyalgia Impact Questionnaire (FIQR) and Hospital Anxiety and Depression Scale (HADS). Chronic pain intensity was assessed using a numerical rating scale. Pain sensitivity was measured using pain pressure thresholds, wind-up pain, and aftersensations. Respiratory rate, respiratory rate variability, and tidal volume variability were measured noninvasively using a thoracic bioimpedance electrode during restful waiting.

RESULTS: No association was observed of respiratory variability with fibromyalgia impact, anxiety, chronic pain intensity, wind-up pain, and aftersensations. Higher depression scores were associated with lower tidal volume variability (r = -0.45, 95% CI: -0.04 to -0.73, p = 0.033). Additionally, higher pain pressure thresholds correlated with lower respiratory rate variability (R = -0.43, 95% CI: -0.02 to -0.72, p = 0.039) and tidal volume variability (R = -0.47, 95% CI: -0.07 to -0.74, p = 0.023).

CONCLUSION: While no direct association was found between respiratory variability and overall fibromyalgia impact, respiratory variability was associated with depression and pain sensitivity, both of which influence quality of life. These findings suggest that respiratory variability may have potential as a biomarker reflecting specific symptom dimensions of fibromyalgia. Further research is warranted.