Correlation between TSH levels and quality of life among subjects with well-controlled primary hypothyroidism.

PURPOSE: It has been suggested that increasing levothyroxine dose to lower TSH levels within the normal laboratory range might be a therapeutic option for patients with apparently well-controlled primary hypothyroidism who are dissatisfied with their treatment and complain of physical or psychological symptoms. This study assessed whether there is a relationship between TSH levels and health-related quality of life (HRQoL) among subjects with adequately treated hypothyroidism. METHODS: HRQoL was measured with the specific thyroid disease ThyPRO-39 questionnaire in 218 consecutive patients with primary hypothyroidism of any cause attending an Endocrinology Department in a single center. Patients had TSH values within the normal laboratory range on a blood test performed not before than 6 weeks prior to study participation, but they were not aware of their lab results. The association between TSH values and the different ThyPRO-39 scales was analyzed by means of multiple regression models, both linear and additive, in which, in addition to TSH, a wide set of clinical and sociodemographic variables potentially related to HRQoL were also considered. RESULTS: TSH levels and the use of anxiolytic and antidepressant drugs were the only variables that showed a positive linear correlation with the ThyPRO-39 composite scale in the multivariate regression analysis, indicating greater impairment in HRQoL with increasing TSH values. TSH was also independently correlated to scores of scales dealing on tiredness and emotional susceptibility. CONCLUSIONS: In patients with primary hypothyroidism, higher TSH values, even within the normal reference range, are associated with greater deterioration of HRQoL.

TSH Level and Risk of Malignancy in Patients with Bethesda Category IV Thyroid Nodules.

Fine needle aspiration biopsy does not permit to distinguish between benign and malignant follicular thyroid lesions (category IV in the Bethesda Cytopathology System). Some reports have suggested an association between increased serum TSH levels and thyroid cancer, so the aim of this study was to investigate the association between TSH levels and malignancy in patients with follicular thyroid nodules. Therefore, we conducted a retrospective study of all subjects who underwent surgical treatment for Bethesda IV thyroid nodules in a single center (years 2012-2017). A total of 127 patients were analyzed, and malignancy was present in 38.6% of the patients. Using ROC analysis, the best TSH cut-off point to differentiate benign from malignant disease was 2.1 mU/l and the age cut-off with better sensitivity and specificity was 47 years. The proportion of subjects with TSH ≥ 2.1 mU/l was greater among subjects with cancer than in those with benign diseases (65.3 vs 44.9%, P = 0.029). The concurrence of both cut-off points (TSH ≥ 2.1 mU/l and age ≥ 47 years) showed a higher diagnostic accuracy than either of the two variables separately. Therefore, the present study supports an association between serum concentrations of TSH and risk of malignancy among subjects with Bethesda IV thyroid nodules. TSH levels could modify the diagnostic and therapeutic approach of patients with Bethesda IV nodules.