Prevalence of thyroid disorders and metabolic syndrome in adult patients with rheumatoid arthritis

Background: The clinical association between rheumatoid arthritis (RA) and hypothyroidism is important as both these conditions are associated with metabolic syndrome (MetS) which in turn makes the patients more prone for cardiovascular disease. Material and methods: In this cross-sectional study, the prevalence of thyroid disorders and MetS were studied in 54 consecutive adult patients with RA (mean age 46.0±10.4 years; 48 females) and 54 age and gender-matched healthy control subjects. Results: The prevalence of thyroid disorders was higher in patients with RA than in control subjects; however, this difference was not statistically significant [19/54 (35.2%) Vs 12/54 (22.2%); p=0.201]. Nine patients with RA already known to have hypothyroidism were receiving levothyroxine treatment. Among the remaining RA patients (n=45), a significantly higher prevalence of autoimmune thyroid disease (AITD) (10/45 Vs 4/54; 2=4.437, p=0.045) and subclinical hypothyroidism with anti-thyroid peroxidase (anti-TPO) antibody positivity (4/45 Vs 0/54; 2=5.002, p=0.040) were observed compared with healthy control subjects. The prevalence of MetS was higher in patients with RA than in control subjects; however, this difference was not statistically significant [31/54 (57.4%) Vs 25/54 (46.3%); p=0.336]. Conclusions: A significantly higher prevalence of AITD and subclinical hypothyroidism with anti-TPO antibody positivity in patients with RA suggests that these patients would benefit from screening for AITD. The co-existence of hypothyroidism and RA reiterates the need for monitoring and early identification of cardiovascular risk factors in patients with RA.