Serum TSH level stability after 5 years in euthyroid adults at low risk for thyroid dysfunction

ABSTRACT Objective: To evaluate changes in thyroid function after 5 years, the interval proposed for new assessment, in initially euthyroid adults. Subjects and methods: Initially, 1,426 apparently healthy adults considered low risk for thyroid dysfunction, were evaluated by measurement of TSH. After 5 years, 1,215 (85.2%) subjects were reevaluated. Results: After 5 years, four subjects were receiving levothyroxine (L-T4) replacement therapy and 25 others had TSH > 4 mIU/L, only two of them with TSH > 10 mIU/L. All of these subjects had TSH > 3 mIU/L in the initial evaluation. During reasse...