RESUMO
BACKGROUND: Patients with pernicious anemia (PA) have a higher prevalence of other autoimmune diseases. We assessed the correlation between PA and autoimmune thyroid diseases (AITD), and evaluated the risk factors for this association. METHODS: A longitudinal study was conducted involving patients with PA between 2010 and 2017. RESULTS: A total of 86 patients with PA were evaluated, 74 (86%) female, with a median age of 51.5 years. Thyroid abnormalities were detected in 45 (52.3%) patients, including 28 (32.3%) hypothyroidism, 3 (3.5%) hyperthyroidism and 20 (23.3%) thyroperoxidase antibody positivity. Logistic regression analysis identified risk factors for having AITD in PA patients: weight loss (OR 12.03; 95% CI 1.06-137.02, P=0.045), diabetes mellitus (OR 4.68, 95% CI 1.15-26.58, P=0.047) and gastric antibodies positivity (OR 5.05, 95% CI 1.45-18.24, P=0.013). CONCLUSION: PA and AITD are frequently associated, suggesting all patients with PA should be investigated for occult thyroid disease, especially those with weight loss, diabetes mellitus and gastric autoantibodies.