Endocrine Abstracts

Introduction: Hyperthyroidism is a pathological state characterized by increased synthesis and secretion of thyroid hormones (thyroxine (T4) and triiodothyronine (T3)) by the thyroid gland. Subclinical hyperthyroidism – a milder form – is defined as a low or suppressed TSH (<0.4 mIU/l), but serum free T4 (FT4) and free T3 (FT3) within the reference interval.

Case: 76 years old lady seen in endocrine clinic. She was referred by GP because of concerns regarding subclinical hyperthyroidism. She has background history of COPD, Psoriassis, and Osteoarthritis. Her usual medications included Salbutamol inhaler, Fostair inhaler and Otezla (Aprimelast-for psoriasis). She has been having periodic bloods with the GP and found out to have subclinical hyperthyroidism. On assessment in the clinic patient has mentioned that she is generally lethargic and tired. There has been no change in her weight. She has occasional palpitations that mainly occur during the night. There was no history to suggest of fractures or low trauma fractures. She mentioned that she was previously diagnosed as having hypothyroidism and was on Levothyroxine tablets. She stopped taking those tablets 10 years ago. On clinical examination there were no signs of thyroid disease and no thyroid enlargement. Her heart sounds were normal to auscultations and there were no tremors too. She had been feeling unwell from psoriasis recently but there were no features of hyperthyroidism on history and clinical examination. TPO Antibodies were negative. Her Thyroid Receptor anti bodies have been sent and awaiting results. She was started on low dose. Bloods for central hypothyroidism were done and were normal too. Considering that she has grade II subclinical hyperthyroidism, her age and potential complications, she has now been started on low dose Carbimazole 5 mg per day and will be followed up in clinic in due course for further review plus consideration of radioactive iodine if needed.

Discussion: Treating subclinical hyperthyroidism is an open question amongst the endocrinologists. However, individualised treatment is necessary and the aim of the treatment is to restore thyroid state and avoid complications.