Background/Purpose: Fatigue is a common and debilitating complication in patients with rheumatoid arthritis (RA). Its mechanism is not fully elucidated, and when persistent is often challenging to manage. It often does not fully resolve despite treatment with DMARDs thus raising the necessity to uncover other factors that might influence its improvement. This study aimed to explore the characteristics that might have an influence on fatigue improvement in adult patients with RA.

Methods: A single-centered prospective cohort study of patients ≥18 years old who were enrolled in the Corrona RA Registry from 2011 to 2020. Fatigue level was measured using the fatigue Visual Analog Scale (VAS-F) 0-100 at the time of enrollment and 6, 12 and 24 months follow-up appointments. The minimal clinically important difference (MCID) for the fatigue VAS (6.7% change from baseline) was used to assess the change in fatigue level compared to baseline. Univariate and multivariate (adjusting for age, gender and BMI) logistic regression analyses were performed to examine the association between fatigue improvement at 12 months and a wide variety of baseline demographics and disease characteristics.

Results: One hundred and eleven patients with RA were identified, of which 52 reported fatigue scores at 12 months. The median (interquartile range [IQR]) for age was 55 (44-61) years and the majority were Caucasian (67%), females (88%), and with an above-average BMI (71%). The median (interquartile range [IQR]) of the fatigue scores at enrollment and 12 months were 40 (8-70) and 38 (5-58), respectively. At 12 months, fatigue level improved in half of the population (Table 1).

In a univariate analysis, several predictors were noted to be associated with improved fatigue scores. These included female gender (p< 0.001), non-smokers (p< 0.01) and increased baseline fatigue levels (p=0.04). Several other variables, including depression, showed a trend towards significance. These variables were further investigated by multivariate analyses (adjusting for age, gender and BMI). As may be expected, each additional unit in baseline fatigue was associated with a 2.7% increased likelihood of improvement in fatigue at one year (OR 1.027, 95% CI 1.006-1.048, p=0.01). Additionally, non-smokers were found to be highly likely to improve fatigue levels at year-end (OR 7.63, 95% CI 1.11-52.63, p=0.04) and those with baseline depression were found to be highly unlikely to improve fatigue levels (OR 0.17, 95% CI 0.03-0.82, p=0.03).

Many other variables were examined, and none found to be significantly associated with the outcome of interest including BMI, employment status, physical activity level, pain control, number of comorbidities, duration of RA, change in CDAI score, starting biological DMARDs, or RF and CCP seropositivity.

Conclusion: We observed in this cohort study an improvement in fatigue level in half of the population. Fatigue improvement was associated with female gender, non-smokers, lack of depression and higher levels of fatigue at baseline.

Table 1. Fatigue score and progression in the study participants at 6, 12 and 24 months compared to baseline.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/what-influences-fatigue-improvement-in-rheumatoid-arthritis-a-prospective-cohort-study/