Key references discussed in the episode:
Key take-home messages from the episode:
- Subclinical hyperthyroidism is diagnosed when thyroid-stimulating hormone (TSH) is suppressed below the normal reference range, but free thryoxine (FT4) and free triiodothyronine (FT3) concentrations are within the normal reference range.
- Affects 5% of those aged >60 years.
- More than 50% of cases of isolated low TSH with normal free hormones will return to normal with no treatment.
- Causes include Grave’s disease, toxic thyroid nodules, thyroiditis and non-thyroidal illness. Iatrogenic causes include steroids, amiodarone, dopamine agonists, cancer immunotherapies and antiretrovirals.
- Main concern with subclinical hyperthyroidism is potential exacerbation of conditions such as atrial fibrillation, ischaemic heart disease and osteoporosis.
- If any of these conditions present, discuss with endocrinology for consideration of treatment.