A 23 year old asymptomatic woman attends her family physician for thyroid function testing as her mother has recently been commenced on levothyroxine. Thyroid functiontests (TFTs) show TSH 6miU/L, and free T4 of 12.4 pmoi/L (0.96 ng/dL). Her serum thyroid peroxidase antibodies are strongly positive. What is the most appropriate management plan?

This woman has subclinical hypothyroidism. There is no benefit in checking thyroglobulin antibodies as it does not change her diagnosis or management. With positive thyroid peroxidase antibodies she has a higher risk of progression to overt thyroid failure. A trial of thyroxine replacement would be advocated if her TSH was > 1 0 miU/L or she developed symptoms suggestive of progression to clinical disease. Reviewing her biochemistry and symptomatology is therefore necessary.