Endemic goiter in the Cauca Valley. 3. Role of serum TSH in goitrogenesis.

Abstract

ABSTRACT Goiter exists in children of the Cauca Valley despite adequate prophylaxis with iodine. Previous studies suggested that goitrous glands from patients from the Cauca Valley are normally sensitive to thyroid stimulating hormone (TSH) and have an adequate functional reserve. The findings have been interpreted to mean that intrathyroid factors are primarily responsible and TSH activity is viewed as having a permissive rather than a causative role. To test this hypothesis further, TSH levels in serum of boys 9–15 yr old with a known attack (incidence) rate of goiter of 18% were determined by radioimmunoassay. There was a higher prevalence of goiter in the Cauca River area than in the Cali River area and in children from the lower socioeconomic class than in those from the higher socioeconomic class. TSH was within the normal range in all patients studied, and no correlation with goiter was found. The same was true for total thyroxine, T3 resin uptake, and thyroxine binding proteins. We suggest that go...