Background Fatigue is a frequently occurring multidimensional symptom in patients with RA and can be as difficult to cope with as pain. Fatigue affects every sphere of life and may cause major distress. The relationship between fatigue, disease activity and personal factors is still unclear. Some patients experience high levels of fatigue even if the treat-to-target goal of remission or low disease activity is achieved. Among disease-related factors pain and disability are found to be strongly associated with high levels of fatigue.¹

Objectives To explore possible relationships between demographic variables, disease-related factors, disability, and fatigue in a Norwegian cohort of RA patients who had achieved low disease activity or remission after six months DMARD-treatment.

Methods A total of 2193 RA patients (age ≥18 years) starting either methotrexate (MTX) monotherapy as their first DMARD, or a TNF-inhibitor (TNFi) in combination with MTX as their first DMARD were retrieved from the Norwegian DMARD-register (NOR-DMARD). At 6-month follow-up 699 (32%) patients were in low disease activity (DAS28 2.6-3.2) or remission (DAS28 <2.6). In this sample, bivariate and multivariate linear regression analyses were conducted with fatigue (Visual Analogue Scale; VAS, 0-100 mm) at 6 months as dependent variable. Age, gender, disease duration, and baseline ESR, 28 swollen and tender joint counts, pain (VAS, 0-100 mm) and disability (modified health assessment questionnaire; MHAQ) were tested as predictors of fatigue level at 6 months. Furthermore, we examined cross-sectional associations between fatigue and the respective variables at 6 months, and also between fatigue and treatment group (MTX mono or TNFi+MTX).

Results At 6 months, the median (25, 75 perc.) level of fatigue was 20.0 (6.0, 43.0). By bivariate regression analyses female gender, number of tender joints, higher disability and higher pain at baseline significantly predicted higher fatigue at 6 months (all p-values <0.001). In the multivariate analysis lower ESR and higher pain were statistically significant predictors (p<0.001) of higher fatigue. By multivariate cross-sectional analysis at 6 months, lower age and higher pain were significantly associated with higher fatigue (p<0.001).

Conclusions Pain levels at baseline and 6 months were associated with higher level fatigue in patients achieving low disease activity with DMARD treatment. These results support the previously reported relationship between pain and fatigue in RA, and indicate that also patients in low disease activity may need non-pharmacological interventions in addition to the DMARD-treatment to manage their pain and fatigue.

References

1. Nikolaus S et al. Fatigue and Factors Related to Fatigue in Rheumatoid Arthritis: A Systematic Review. Arthritis Care Res 2013; 65(7): 1128-1146.

Disclosure of Interest None declared