Epidemiologic and Metabolic Studies of a Goiter Endemic in Eastern Kentucky

Abstract

In a small community located in an endemic goiter area in Eastern Kentucky, 33.1% of the entire population was found to have enlarged thyroid glands. Below the age of 40 there was no difference in the goiter prevalence rates of the sexes. Dietary iodine deficiency of the population as determined by iodide blood levels, estimated daily urinary iodine excretion, and dietary iodine intake, was not demonstrated as a primary factor. The most striking difference between goitrous and nongoitrous individuals living in the same community was an increased absolute iodine uptake (AIU, μg/hr) in those persons with thyroid enlargement. The elevated AIU's were accompanied by normal PBI concentrations in the serum, suggesting an intrathyroidal metabolic defect in iodine utilization or positive iodine balance with storing of iodine in the thyroid. Genetic and environmental factors were also investigated. The geographic distribution of households with goitrous persons was random, but the distribution of goiter within households was nonrandom. Bacteriologic and chemical analyses of water supplies did not reveal quantitative differences between goitrous and nongoitrous households, but all water supplies were polluted. Because of the failure to demonstrate iodine deficiency, further study of other environmental and genetic factors is warranted in this and other goiter endemics.