ENDEMIC GOITRE IN THAILAND

Abstract

SUMMARY (1) In a village in the endemic-goitre area in Thailand, studies of the iodine metabolism (127I as well as 131I, and including chromatographic analysis of thyroid biopsy digests) have been made on 35 subjects sampled particularly from the younger decades. (2) The high 24-hr. uptake of 131I by the thyroid was correlated inversely with the urinary 127I-iodide excretion; the [131I]thyroid discharge rate was very rapid in the diffuse goitres of young subjects, less so in the older subjects with nodular goitres, and was not rendered normal by a previous iodide repletion. (3) Thyroid biopsy studies on some of these subjects showed: (a) in the three diffuse endemic goitres of young subjects studied, low iodine concentrations, rapid formation of [131I]iodothyronines, a normal MIT:DIT ratio (< 1) and a normal distribution of 127I-iodoaminoacids; (b) in two nodular endemic goitres in older individuals total iodine concentration was similarly low, but the rate of formation of [131I]iodothyronines was very slow, the MIT:DIT ratio high (> 1), and the 127I-iodoaminoacids stored consisted preponderantly of iodotyrosines, as found also in twenty sporadic goitres in Londoners. (4) These findings suggest that hormone synthesis was normal and rapid in the diffuse endemic goitres of the young subjects, but defective in the nodular endemic goitres of older subjects, as was also found in sporadic goitres.