gms | German Medical Science

Introduction: In chronic inflammatory disease non-articular symptoms such as fatigue and symptoms of autonomic dysfunction contribute significantly to disease burden. Despite their importance, knowledge about the relationship between inflammation, fatigue and autonomic dysfunction is limited. Since severity of fatigue is not assessed in rheumatologic routine diagnostic tools as well as promising and easy to employ treatment strategies are scarce and display a difficult clinical challenge.

Methods: To assess the relationship between fatigue, autonomic disfunction and disease activity in chronic inflammatory disease we designed a cross-section cohort study. In 36 patients with diagnosed rheumatoid arthritis (RA) we measured pupillometric parameters, fatigue by the Fatigue Severity Scale questionnaire, autonomic disfunction by the COMPASS-31 questionnaire and The Clinical Disease Activity Index (CDAI). Mann–Whitney U test was used to compare medians of groups. Correlations were tested by Spearman’s Rho or Pearson’s r whenever applicable.

Results: Disease activity reported by CDAI showed a median of 7.0 [3.0, 11.0], n=26 (72%) patients were in remission or had low activity, n=9 (25%) had moderate or high activity. Fatigue severity scale showed a median of 4.0 [2.0, 5.0]. Fatigue scores were significantly higher in the group with moderate or high activity (3.5 vs. 5.0; p<0.05). We found significant correlation between fatigue and the COMPASS-31 questionnaire (p<0.05), whereas there was no correlation between CRP or blood sedimentation rate and fatigue. Pupillometric measurement of resting diameter and constriction velocity were significantly correlated with fatigue scores (p<0.05 and p=0.02 respectively). Constriction velocity also was significantly correlated with COMPASS-31 (p<0.05). There was a negative correlation between age and resting diameter and constriction velocity (p<0.001).

Conclusion: In our cohort patients with higher disease activity report higher fatigue which is associated with questionnaire-measured autonomic dysfunction. Our results suggest a connection between the autonomic nervous system and the extent of fatigue that seems mostly independent of humoral inflammation. Furthermore, pupillometry proved to be a possible objective tool for measuring fatigue. Besides common questionnaires, pupillometry could therefore be used as a complementary tool for testing therapeutic interventions to reduce fatigue.

Disclosures: No conflict