A recently published study by Swedish doctors suggests that patients with rheumatoid arthritis (RA) experienced greater fluctuations in general and disease-related fatigue during the winter compared with the summer.
In this study, researchers recruited 65 patients from their clinic to participate in a yearlong study. Patients were 54 on average, three-quarters were women and the average disease duration was 15 years. Individuals were evaluated 7 times over the course of one year,
The study found that self-reported fatigue was worse in the winter months compared with the summer. The highest fatigue scores were reported in December and January, and the greatest difference was between January and September. The doctors identified statistically significant seasonal variations in general fatigue and in the physical aspects of fatigue, both suggesting that persons with RA experience greater fatigue during the winter.
Importantly, there were no seasonal variations in patient-reported pain, global health or in physical function measured on a Health assessment Questionnaire.
Several other factors that could contribute to seasonal variations in fatigue include physical activity, which correlates inversely with fatigue and tends to be more frequent in the spring and summer. Vitamin D deficiency also could contribute, as might the large variations in temperature and daylight hours in Sweden, and may in part reflect a connection to seasonal affective disorder, which is known to affect symptoms of depression (including fatigue) in the general population.
Reference: Feldthusen C, Grimby-Ekman A, Forsbald-d’Elia H, et al. Seasonal variation in fatigue in persons with rheumatoid arthritis: a longitudinal study. BioMed Central. Abstract DOI: 10.1186/s12891-016-0911-4. Published Feb 4, 2016. Access at: http://bmcmusculoskeletdisord.biomedcentral.com/articles/10.1186/s12891-016-0911-4