Studies of the control of thyroid function in endemic goiter in Eastern New Guinea.

Abstract

Studies of the control of thyroid function in endemic goiter have been carried out in the rugged mountainous Huon Peninsula of Eastern New Guinea, where there is severe iodine deficiency. In 91 natives living in the endemic area the mean urinary iodine was 12 ± 12 μg/day compared with 49 ± 55 in 31 coastal natives. Observations on 131I uptake in native villages with portable equipment revealed a higher 24-hr 131I uptake in 59 goitrous natives (77 ± 13 %) than in 122 nongoitrous natives (67 ± 20 %). The serum PBI was lower in 85 goitrous natives (2.9 ± 1.7) than in 119 nongoitrous natives (4.9 ± 2.0). The T3 resin uptake was also lower in 80 goitrous natives (86 ± 15) than in 115 nongoitrous (94 ± 18). Serum TSH levels estimated using the McKenzie method revealed a significant elevation in goitrous but not in nongoitrous natives. Administration of T3 in a dosage of 120 μg daily to 6 natives for 5 days was followed by a fall in 24-hr 131I uptake from 81 to 41 %. Observations in 43 natives who had received iodized oil injections 3 yr before revealed a mean 131I uptake of 37 ± 19% and urine iodine (in 29) of 35 ±25 μg% day. Observations in 51 natives who had received oil 18 months before revealed an uptake of 30 ± 19% and urinary iodine (in 18) of 119 ± 114 μg/day. Significant levels of serum TSH could not be detected in these natives nor in 16 goitrous natives who had shown significant regression of goiter following iodized oil injection 3 months before. It is concluded that the lower serum PBI and elevated serum TSH level in the goitrous compared with nongoitrous natives indicate a failure in adaptation to iodine deficiency. The condition can, however, be readily reversed by correction of the iodine deficiency with iodized oil.