PREVALENCE OF INCIDENTAL THYROID-DISEASE IN A RELATIVELY LOW IODINE INTAKE AREA

An ultrasonographic survey of thyroid abnormalities was conducted in 5 47 consecutive apparently normal overweight subjects (380 females and 167 males), aged 27-58 years in an urban area with relatively low iodi ne intake (mean daily urinary iodine excretion: 10.6 mu g/dL). Individ uals with any previous thyroid disease or familial thyroid pathology w ere excluded. In 240 subjects (44%) high resolution ultrasonography of the thyroid was considered normal, In 307 individuals (56%) abnormali ties of the echo structure (39%) or thyroid nodular disease (17%) were detected by ultrasonography, Marked heterogeneity of the echo structu re that was considered suggestive of chronic autoimmune thyroiditis wa s present in 81 subjects (15%). In 72 of these patients the serum anti -TPO levels were positive by a sensitive RIA, Thyroid nodules either s olid or predominantly cystic were present in 90 subjects (17%). Eighte en patients had a relatively large nodule (diameter 15-48 mm), Eleven of these nodules were missed at clinical examination. Fine needle aspi ration cytology was performed in 14 patients and 7 individuals underwe nt thyroid surgery. In 6 subjects the pathologic diagnosis was benign adenomatous goiter and one patient had a follicular carcinoma. Thyroid function studies confirmed subclinical hypothyroidism in 27 patients (4.9%), all of them with elevated serum anti-TPO autoantibodies levels , It was concluded that the overall occurrence of thyroid disease is m ore common than suspected by clinical examination.