Management of subclinical hypothyroidism in adults

Subclinical hypothyroidism (SCH) is defined as moderately elevated thyroid-stimulating hormone (TS H) concentration in the presence of serum free thyroxine (fT4) and triiodothyronine (fT3) concentrations within the population reference range. The clinical presentation varies widely, ranging from no symptoms to clear manifestations of hypothyroidism. The prevalence has been reported to range from 4–10% depending upon the gender, age and population studied. An initially raised serum TS H, with fT4 within reference range, should be investigated with a repeated measurement of both serum TS H and fT4, along with thyroid peroxidase antibodies, preferably after 2–3 months. L-thyroxine (LT 4) therapy is recommended especially for patients below 65 years, with a persistent serum TS H of more than 10 mIU /l, with symptoms suggestive of hypothyroidism,

after hemithyroidectomy or with positive antithyroid peroxidase antibodies. If the decision is to treat, then oral L-thyroxine therapy is the treatment of choice. The dose of L-thyroxine should be adjusted gradually and closely controlled. The goal for majority of patients should be to achieve a stable serum TS H in the lower half reference range. In the elderly, any treatment for SCH should be individualized, both indications and contraindications should be taken into account. Once commenced on L-thyroxine treatment, then clinical state and serum TSH should be controlled at least annually thereafter.