Clinical and subclinical autoimmune thyroid disorders insystemic sclerosis

Objective: Several studies have reported the association of systemic sclerosis (SSc) with thyroidautoimmune disorders, but most of them have neither an appropriate control group nor include acomplete thyroid work-up.Design: The aim of our study was to evaluate the prevalence of thyroid disorders in a large number ofpatients with SSc using a complete clinical evaluation.Methods: Thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine, antithyroglobulinand antithyroid-peroxidase (AbTPO) autoantibodies, thyroid ultrasonography and blood flow and fineneedle aspirationwere performed in 202 SSc patients versus 404 gender- and age-matched controls fromthe general population, with similar iodine intake, to evaluate the prevalence of clinical and subclinicalthyroid disorders.Results: Odds ratio (OR) for female SSc versus controls was: for subclinical hypothyroidism, 3.2(95% CI)Z1.8–5.7); for clinical hypothyroidism, 14.5 (95% CIZ2.3–90.9); for AbTPO positivity,2.7 (95% CIZ1.8–4.1); for hypoechoic pattern, 3.2 (95% CIZ2.2–4.7); for thyroidautoimmunity, 3.7 (95% CIZ2.6–5.4); for thyroid volume !6 ml, 1.8 (95% CIZ1.2–2.7).OR for thyroid autoimmunity in male SSc versus controls was 10.8 (95% CIZ2.2–52.4). Meanvalues of TSH in female SSc, and of AbTPO in female and male SSc were higher (P!0.01) thanin controls. We observed three cases of Graves’ disease in female SSc versus zero in controls(PZ0.0140), and two cases of papillary thyroid cancer in SSc patients.Conclusions: Thyroid function, AbTPO and ultrasonography should be tested as part of theclinical profile in SSc patients. Females, subjects with positive AbTPO and hypoechoic and smallthyroid should have thyroid function follow-up and appropriate treatment in due course.