THE IODINE BALANCE IN NODULAR GOITER1 2

Patients with toxic nodular goiter present an increased urinary excretion of iodine. This is greater than that observed in patients with exoph-thalmic goiter (1). The blood iodine and the basal metabolic rate are also increased, but to a lesser degree than in exophthalmic goiter (1). In non-toxic nodular goiter, however, the urinary excretion of iodine, the blood iodine, and the basal metabolic rate are normal or may be even decreased (3). More recently we have found that the iodine metabolism of exophthalmic goiter is greatly aug-mented (2). This is shown in the elevated blood iodine, the increased excretion of iodine through one or all excretory channels, and the increased negative iodine balance on a low iodine intake. It consequently appeared desirable to extend bal-ance studies to patients with nodular goiter, in order better to compare the iodine metabolism in these three thyroid diseases. We have therefore determined the iodine balance of two patients with non-toxic nodular goiter over a total period of 36 days and that of two patients with toxic nodular goiter over a total period of 54 days. METHODS Our experimental and laboratory methods have been given (2, 4, 5). A constant regimen of hospital management was begun five to six days prior to investigation and then maintained throughout the period of study. The daily diets were selected from a limited number of foods. They were low in iodine and calcium content, ade-quate in other respects, and as attractive as pos-sible. They were constant for each individual during the preoperative period. The iodine con-tent of the food as actually served to each patient was determined (2)