A survey of schoolchildren from a severe endemic goitre area in Spain.

All the boys and girls between six and fourteen years old regularly attending school in three villages from an area in Spain known ass Las Hurdes were studied with respect to thyroid size, body weight and height. Casual urine samples were obtained for the determination of iodine and creatine concentrations. Capillary blood was spotted on filter paper and used for the determination of thyroxine and thyrotropin by radioimmunoassay. The same survey was carried out in 354 school children from Madrid, whose data were used as a reference of the adequacy of the methods employed in Las Hurdes. Goitre prevalence was very high, the overall frequency being 86 per cent. The concentration of iodine in the urine was less than 20 micrograms/1 in 71 per cent of the school children. The concentration of creatine in the urine was also half that found in children from Madrid, and the daily creatine excretion in children from Las Hurdes was lower than expected from their body weight. Their somatic development, as measured by height and weight, was retarded markedly, both as compared to the Madrid reference group and to international charts. Serum T4 was less than 78 nmol/l ( micrograms/kl) in 46 per cent, of the children from Hurdes, and serum TSH greater than 7.5 mU/l in 40 per cent. A relatively low stature (below the 10th percentile) was associated with either a low serum T4, an elevated serum TSH, or both, in 30 per cent of the children. These results indicate that the persistence of endemic goitre in Las Hurdes is of great significance and that there is a continuing risk of the birth of cretins. Observations made a decade earlier in the same area show that the goitre endemic is not diminishing, and that an iodization programme is urgently needed. It also appears that a high proportion of the "normal' schoolchildren have features found in hypothyroidism.