RESUMO
Context: Although, many studies have been made on the clinical course of autoimmune thyroiditis, this study focused on women and the factors effecting the natural course such as Selenium. Objective: The study aimed to determine Hashimoto's thyroiditis (HT) clinical course in adults and the factors that could affect it. Design: The study was in a retrospective manner between 2010-2018. Subjects and Methods: 101 patients with HT were followed for 60.7±32.7 months. Biochemical and ultrasonographic data were collected. We investigated whether the age at diagnosis, family history, smoking habits, levothyroxine replacement therapy, and serum selenium (Se) levels influenced the disease course. Results: No relationship was observed between age and thyroid functions, thyroid volumes (TV), and autoantibody (Ab) levels at diagnosis. Ab levels were irrelevant with TV, echogenicity, and nodularity at diagnosis. However, initial TSH levels were significantly associated with anti-TPO levels (p=0.028, r=0.218). In the untreated group, thyroid functions seemed to be stable. TV decreased significantly in both treated and untreated patients (p<0.001). The decrease in TV was significantly higher in the treatment group (p=0.002). In euthyroid and subclinical hypothyroid patients, levothyroxine therapy did not affect the decrease in TV. Ab levels remained stable in untreated patients, but anti-TPO levels significantly decreased in treated patients (p<0.001). Smoking seemed to increase only anti-Tg levels (p=0.009). Family history was not associated with any of the studied parameters. Serum Se level was negatively correlated only with thyroid echostructure and only in treated patients. TV showed a "Gaussian distribution" in all patients at the diagnosis and at the end, independent of levothyroxine treatment. Conclusions: Most euthyroid patients remained euthyroid during five years of follow-up. The decrease in TV was significantly prominent with LT4 treatment. Importantly, TV followed a normal distribution instead of the bimodal distribution that is classically described.
