| Bernet, Washington, DC, USA, investigated if nyctohemeral TSH variations persist in patients on T4 treatment. Patients were divided on the basis of minimal TSH (between 08 and 20 hrs) in 3 groups: TSH <0.1; between 0.1-0.4; and >0.4 mU/L. Mean percent increase (between 20 and 08 hrs) was 183, 237, and 275 respectively. It is concluded that TSH measurements at customary clinic hours does not necessary reflect TSH activity throughout 24 hours and that alternate dosing regiment might be necessary certainly in patients with thyroid carcinoma, in whom TSH should be suppressed continuously. |
