Prevalence and Patterns of Thyroid Dysfunction in Patients withRheumatoid Arthritis

摘要

Background: The relationship between Rheumatoid Arthritis (RA) and Autoimmune Thyroid disturbance is oneof the numerous examples of autoimmune comorbidities that are already established. This has been investigated in manycountries and different populations, but data are still missing in some countries. We aimed to investigate comorbid RAand autoimmune thyroid disturbance in the Saudi population.Methods: We conducted this retrospective study at a tertiary-teaching center, in Saudi Arabia. We reviewed data of all RApatients, over the last 14 years, and selected all those who had thyroid function results recorded in their laboratory data(free thyroxine, free triiodothyronine and Thyroid-stimulating hormone). We examined all laboratory results of thesample, to assess prevalence of different thyroid disturbances, in regards to the laboratory standard results. We alsoanalyzed the relationship between abnormal thyroid results and the usual inflammatory and autoimmune parameters:Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein level (CRP), Rheumatoid Factor (RF) and AntiCycliccitrullinatedPeptide (anti-CCP). We used both Chi-square testing and Pearson correlation test, whenever indicated,and P-value less than 0.05 to assess significance.Results: One hundred and fifty one (151) patients had their thyroid function tests recorded. We observed the following:high prevalence of thyroid function disturbances in our sample of RA patients, compared to non-RA patients]. (26.3% and7% respectively), with the patterns of thyroid dysfunction as follows: Subclinical hypothyroidism in 29 patients (19%),Hypothyroidism in 6 patients (4%), Subclinical hyperthyroidism in 4 patients (2.6%) and hyperthyroidism in 1 patient(0.7%). No patients were recorded as Euthyroid sick syndrome. Also there was a significant positive correlation betweenTSH and CRP (r=0.22, P=0.029).Conclusion: There is a high prevalence of comorbid hypothyroidism in our RA patients, in a tertiary care hospital inWestern Saudi Arabia. Physicians should be aware of screening RA patients for this comorbidity, especially when thespecific symptoms may overlap between both diagnoses.