Sjögren’s Symptoms Not Affected by Seasonal Changes, Study Finds
Seasonal changes do not appear to significantly influence the main symptoms of primary Sjögren’s syndrome — pain, fatigue, and dryness — according to a large study.
The study, “Seasonal effect on fatigue, pain and dryness in primary Sjögren’s syndrome,” was published in the journal Arthritis Research and Therapy.
Despite being the second most common autoimmune disease, preceded only by rheumatoid arthritis, little is known about the impact of seasonal effects on symptoms of primary Sjögren’s syndrome.
To address this, a team of French researchers examined the changes in pain, fatigue, and dryness in Sjögren’s patients who participated in three placebo-controlled clinical trials – TRIPSS, TEARS (NCT00740948), and JOQUER (NCT00632866) — in which the active treatment did not provide benefits, and in the ASSESS prospective cohort (NCT03040583).
These three symptoms represent most of the disease burden experienced by all patients, and are included in the EULAR Sjögren’s Syndrome Patient Reported Index, an internationally validated tool used in all four trials.
The analysis included 632 patients with a total of 2,858 measures of all three symptoms. These included 744 assessments conducted in spring, 584 during summer, 848 in fall, and 682 in winter.
Results showed no significant differences in scores of pain, dryness, or fatigue across seasons or across months. A composite assessment of all three measures also did not change year-round.
The team next conducted an analysis to examine if factors such as age and type of treatment used were influencing the results. This time, they used an objective measure of dryness (instead of patient-reported dryness) to confirm the findings.
Adjusting for these potential confounding factors did not change the influence of seasons on objective dryness scores. Dryness of the eyes and mouth remained similar across seasons.
Similar adjustments for patient-reported pain and fatigue also did not change the results.
The study “did not show any seasonal effect on the main symptoms of [primary Sjögren’s syndrome], pain, fatigue and dryness,” the researchers wrote.
They noted, however, some limitations to the study, such as the lack of available data regarding important weather variables, including temperature, humidity, precipitation, and sunshine exposure at the time of the assessments, as well as the geographic location of the clinical site where the measures were taken.
“A longitudinal study involving meteorological features and assessing pSS outcomes every months during several years … could be the most accurate way to investigate the effect of seasonality in pSS,” the team concluded.