THE PREVALENCE OF THYROID-DYSFUNCTION AMONG ELDERLY SUBJECTS IN AN ENDEMIC GOITER AREA OF CENTRAL ANATOLIA

The prevalence of thyroid dysfunction in the elderly is reported to be markedly high, at least in some Western countries in which iodine int ake is sufficient or increased because of recent supplementation of io dine for public health. We therefore wished to investigate the prevale nce of thyroid dysfunction among elderly people in an endemic goiter a rea. The study included 198 subjects over the age of 55 years. It was carried out in two towns 20-30 km, south of Kayseri, Central Anatolia. Questioning on medical history, physical examination and grading of t hyroid gland size were performed. Serum TSH was measured by a sensitiv e immunoradiometric assay. Serum free thyroid hormones and thyroid aut oantibodies were measured in the subjects with TSH concentrations belo w 0.4 mu IU/ml or above 4.5 mu IU/ml on the initial screen. Drinking w ater was also analyzed for iodine content. Twenty-five (12.6%) subject s had either elevated (6.5%) or suppressed (6.1%) serum TSH levels. No patient had clinical hypothyroidism (high TSH and low free thyroxine and free triiodothyronine). Three (3.5%) subjects had clinical hyperth yroidism (low TSH and high free thyroxine and free triiodothyronine). Only one subject was positive for antimicrosomal and antithyroglobulin antibodies. The prevalence of goiter was 25.8%. The iodine level in d rinking water was found to be 3 mu g/L. In conclusion, we believe that the prevalence of thyroid dysfunction in the elderly may depend on th e iodine status in the environment. We think that hyperthyroidism due to multinodular goiter is more important than hypothyroidism for elder ly people living in an endemic goiter area, probably due to the low fr equency of autoimmune thyroid disorders.