Can exercising reduce fatigue in rheumatoid arthritis?

This paper studied how physical activity is related to fatigue in patients with rheumatoid arthritis (RA).

Fatigue is common among RA patients, with decreased levels of physical activity being reported in these patients. It was suggested that physical exercise can help treat fatigue, as people with chronic fatigue syndrome are typically less active than healthy people.

The authors aimed to study whether physical activity is associated with fatigue. They also evaluated if pain, disability, coping (managing disease) and cognition (understanding) were related to physical activity.

Data from 167 patients with RA was obtained. Psychosocial variables (social and psychological factors) were recorded using patient questionnaires. Daily activity was recorded using an actometer, which is a device that senses movement. Based on data from the actometer, patients were classified as having low activity (42 patients) or high activity (125 patients). Fatigue level, pain, daily functioning (tasks a person performs daily) and depression levels were also assessed.

Of the 167 patients, 44% were severely fatigued.  The average daily activity score of patients with RA was 73 and this was deemed to be between that of healthy people and patients with chronic fatigue syndrome. The RA patients with a high activity level had an average daily activity score of 83, while those with low activity level had an average score of 43.

High activity patients had significantly lower fatigue level than the low activity patients. Each unit increase in activity related to a 0.08 decrease in the fatigue score. High activity patients scored an average of 4 points lower for fatigue than low activity patients. 60% of patients in the low activity group were severely fatigued compared to 38% of the high activity group. The low activity patient group had significantly higher BMI scores and a significantly higher percentage of women.

Pain, disability, coping, and cognition were not associated with daily activity level.

The authors concluded that patients with a high level of activity have a lower level of fatigue compared to patients with a low level of activity. 

It is unclear if fatigue causes low activity or if low activity causes fatigue.