Fatigue in Patients with Autoimmune Thyroid Diseases

Fatigue is a common feature in a wide variety of chronic inflammatory and autoimmune diseases, but fatigue in autoimmune thyroid disease (AITD) has not been investigated so far. The aim of this study was to examine fatigue in patients with AITD and to analyse the correlation between fatigue and the serum concentrations of thyroid antibodies, thyroid function and depression. This cross-sectional clinical study included 62 patients with increased concentrations of thyroperoxidase antibodies (TPOAbs) as confirmation of AITD and 52 healthy individuals who were negative for thyroid antibodies; all controls were euthyroid. Thyroid antibodies, free thyroxine and thyroid-stimulating hormone were measured in the sera of all subjects. The Fatigue Severity Scale was used to measure the severity of fatigue; the level of depression was measured by the Beck Depression Inventory. Eight (12.9%) patients had evident fatigue, 7 (11.3%) patients had fatigue limit values, and 47 (75.8%) patients had no fatigue. The frequency of fatigue was highly significant and almost three times higher in the AITD patients compared to the control group, in which only 2 (3.8%) patients had evident fatigue. The majority of patients with fatigue had normal thyroid function, and only one (1.6%) patient had overt hypothyroidism. Seven (11.3%) patients had both fatigue and depression, whereas one (1.6%) patient had fatigue without depression. We did not find significant correlations between fatigue and the concentrations of thyroid antibodies, but we found statistically significant correlations between fatigue and depression in AITD patients.