Radioiodine therapy in elderly patients with subclinical hyperthyroidism due to non-voluminous nodular goiter and its effect on bone metabolism.

OBJECTIVE To evaluate 131I therapy in elderly patients with subclinical hyperthyroidism (SCH) due to nodular disease and who did not receive antithyroid drugs (ATDs), and the effect of the treatment on bone metabolism. SUBJECTS AND METHODS Thirty-six patients with TSH ≤ 0.1 mIU/L and non-voluminous goiter (< 60 cm³) were studied. Bone mineral density (BMD) was assessed in 17 women with osteopenia. RESULTS Mean 24-h 131I uptake was 17.5%. Symptoms of thyrotoxicosis were reported by two (5.5%) patients in the first week after therapy. One year after radioiodine treatment, SCH was resolved in 30 (83.3%) patients, and hypothyroidism was detected in one (2.7%). In the patients in whom TSH returned to normal, femoral and lumbar spine BMD increased by 1.9% and 1.6%, respectively, in average. CONCLUSIONS In elderly patients with SCH and non-voluminous goiter, radioiodine not preceded by ATDs is a safe and effective therapeutic alternative. Resolution of SCH has beneficial effects on BMD in postmenopausal women with osteopenia.