Endocrine Abstracts

Subclinical thyrotoxicosis, due to endogenous hyperthyroidism, affects about 1% of the older population and is predominantly caused by indolent progression to a state of autonomous thyroid function in people with nodular thyroid disease. For more than a decade, it has been known that subclinical hyperthyroidism is associated with a three-fold increased risk of atrial fibrillation (Sawin et al.) over 10 years of follow-up. More recently, three separate...

Subclinical thyrotoxicosis, defined as a low serum thyrotrophin (TSH) and normal serum free T4 and T3 concentrations, has been found in up to 3.2% of adults in cross-sectional surveys of thyroid function, of whom 75% have serum TSH concentrations of 0.1 to 0.4 mU/L. If the diagnosis is limited to only those with a serum TSH lower than 0.1 mU/L, the prevalence decreases to 0.7%, with 20% being treated with thyroxine.Thyrotoxicosis is considered overt only...