Risk factors of thyroid dysfunction in patients with rheumatoid arthritis

Introduction:
The study aimed to investigate the complicating thyroid dysfunction situation in patients with rheumatoid arthritis (RA) and to analyze the related risk factors of thyroid dysfunction in RA patients.

Material and methods:
The retrospective analysis of the clinical data and laboratory examinations of 290 cases of RA and 200 healthy individuals undergoing the physical examination was carried out. The thyroid function, anti-thyroid antibodies, and routine laboratory test items were measured. The RA disease activity score (DAS28) was determined in RA patients. Logistic analysis was used to identify risk factors associated with thyroid dysfunction in RA patients.

Results:
The detection rate of RA combined with thyroid dysfunction was 30.0%, which was higher than in the control group (7%, 14 cases). In the thyroid function test, levels of total triiodothyronine (T3) and free triiodothyronine (FT3) were lower, while thyrotropin (TSH), antithyroid peroxidase antibody (TPOAb), and antithyroglobulin antibody (TgAb) were higher in the RA group. There was a difference in hemoglobin (HGB) and total cholesterol (TC) in RA patients with and without abnormal thyroid function.

Conclusions:
Rheumatoid arthritis patients are more prone to develop thyroid dysfunction than healthy individuals, especially hypothyroidism. HGB and TC were correlated with thyroid hormones and antibodies and were risk factors correlated with thyroid dysfunction in RA patients. Clinical work should pay full attention to changes in thyroid function in patients with RA.