Endocrine Abstracts

Introduction: The connection between rheumatoid arthritis (RA) and thyroid disorders (TD) is primarily driven by overlapping immunological mechanisms, shared genetic factors, and similar inflammatory processes. We aimed to discuss some possible causes and triggers that interplay in both conditions based on data from the literature.

Material and methods: Data analysis was done using the systematic search performed in PubMed, MEDLINE, Scopus, Web of Science database of the articles published during the past 5 years related to RA and thyroid disorders. Main factors to consider were age, gender, cortisol, TSH, T4, T3, anti-TPO.

Results: A study of 250 RA patients revealed that 33.9% had thyroid dysfunction, with 24.2% having a prior history of thyroid diseases. Anti-TPO were positive in 32.0% of cases, while AITD was present in 21.5%. Specifically, Hashimoto’s thyroiditis was 2.77 times more common in RA patients compared to those without RA. The prevalence of TD in RA patients was found to be 34%, with Hashimoto’s thyroiditis in 13.5% of cases. Notably, 75% of the RA patients were women aged 20-39 years, with the incidence of hypothyroidism in this group being 3.6 times higher than in men. The inflammatory cytokines TNF-α and IL-6 involved in RA can exacerbate dyslipidemia in hypothyroidism, leading to deteriorated lipid profiles and low HDL levels. Additionally, antithyroglobulin antibodies were found in the synovial fluid of 34 out of 54 RA patients. Steroid therapy, often used in RA management, can induce a hypothyroid state by increasing TSH levels and inhibiting the conversion of T4 to T3.

Conclusion: Endocrine changes during puberty, pregnancy, childbirth, abortion, and iodine deficiency state are considered as risk factors for RA and TD. Screening RA patients for TD is important in prevention of complications. Understanding the intricate relationship between RA and thyroid dysfunctions is crucial for improving patient outcomes through integrated healthcare strategies.