Endocrine Abstracts

Background/objective: The prevalence of low serum TSH in the general population is in the order of 2.5–3.9%, and increases with age. True subclinical hyperthyroidism (SH) (low/suppressed serum TSH, normal serum fT4 and fT3) is less common. In one population based study of 1193 subjects, 66 (5.5%) were found to fit the criteria for SH. Of these, 75% had serum TSH 0.05–0.5 mIU/l, of whom 76% normalised within 12 months. At 12 months 87.5% subjects with serum TSH <0...