Subclinical Hypothyroidism In Childhood, Treatment Or Only Follow-Up?

Abstract Background: Subclinical hypothyroidism is defined as serum levels of thyroid-stimulating hormone (TSH) above the upper limit with normal concentrations of free T4 (fT4). Its management remains challenging. The aim of the study was to evaluate clinical and laboratory findings as well as clinical course of children with SH followed in a third level hospital. 65 patients aged between 2 and 18 years were retrospectively studied. Methods: The patients were followed for a median period of 9 months (range 6 months to 24 months). Those who normalized TSH levels were discharged (Group 1). If TSH persisted mild elevated (5-10µUI/mL) with normal fT4 and negative TPOAb/TgAb were classified as Group 2 and followed semiannually without treatment. In those patients who’s TSH raised ≥10µUI/mL or maintained TSH 5-10µUI/mL and positive TPOAb/TgAb were considered suitable for thyroxin therapy (Group 3, G3). Results: By ROC curves analysis we tested which initial TSH concentration best discriminated between patients who reverted to normality (Group 1) from those who finally required treatment (Group 3), the best cut-off being a TSH concentration >8.1µUI/mL (93.18% E, 57.14% S, AUC 0.765±0.107, p= 0.01). In 89% of our patients, TSH concentrations spontaneously reverted to normality or remained stable without treatment, whereas less than 11% progressed to clinical hypothyroidism. Conclusion: patients with initial TSH concentrations above 8.1µUI/mL have an increased risk of progression to hypothyroidism.