Iodine-deficient area thyroid autoantibodies

A number of studies on the epidemiology of thyroid autoantibodies have been performed as descriptive studies in iodine-deficient areas. Results from some population-based studies from both iodine-deficient and iodine-sufficient areas are shown in Table 60.1. The results are ambiguous. 

Goiter and hypothyroidism due to iodine deficiency are major world health problem. Intake of excess iodine, either in food, water or drugs, may also result in disturbances of thyroid function and goiterl>2 Clinical data as well as animal experiences have shown a sharp rise in the incidence of autoimmune thyroiditis when iodine consumption was increased.2>3,4 Administration of iodine or or iodine containing drugs increases the incidence of thyroid autoantibodies in humans without illness as well as in populations with endemic goiter. Hokkaido is located in the northernmost part of Japan. Separated from the main island by the sea, Hokkaido covers an area of 83,511Km2, and its population of 5.3 million is considerably lower than that of the rest of Japan. 

Thyroid autoantibodies were present in only a few cases, and a search for goitrogens was negative. Further epidemiologic studies showed that endemic areas were located mainly on schistoIithic non-caIcareous soil, with superficial drinking water, deficient in iodine and several other minerals, frequently polluted (Malamos et al. 1971). 

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