Glutathione Peroxidase and Selenoprotein P Evaluation in Well-Being Assessment After Total Thyroidectomy.

It is known that a percentage of patients who undergo total thyroidectomy, approximately 16-34%, complain of symptoms of hypothyroidism or altered quality of life (QoL) despite achieving normal serum TSH values. The present study aimed to identify whether the level of selenium could be responsible for this phenomenon. This pilot cohort study included 44 thyroidectomized outpatients. All patients underwent surgery for benign disease. In this study, no patients with a history of autoimmunity, malignancy, or other conditions that could affect well-being, absorption, or selenium intake were included. Serum levels of TSH, fT3, fT4, Selenoprotein P (SelP), and glutathione peroxidase 3 (GPx3) were measured. The patients also completed the ThyPRO-39 questionnaire to assess their QoL. A strong and significant direct correlation was found between SelP and GPx3 (r = 0.88). However, no correlation was found between hormonal status and SelP or GPx3. Analysis of ThyPRO-39 results did not show clinically significant differences between items nor a correlation with thyroid hormone levels, except for symptoms of hypothyroidism. Interestingly, a significant direct correlation was observed between SelP and tiredness, as well as between GPx3 and tiredness. Furthermore, the fT3/fT4 ratio was correlated with worsening symptoms of hypothyroidism. The results suggest that the selenium status, in turn related to antioxidant activities, as reflected in SelP and GPx3 levels, may be associated with the QoL tiredness domain in thyroidectomized patients, despite normal levels of thyroid hormones. More research is needed to elucidate the role of selenium in the persistent symptoms experienced by some thyroidectomized patients.