Thyroid volume by ultrasound in boys and girls 6-16 years of age under marginal iodine deficiency as related to the age of puberty.

The results of thyroid volume estimation with the aid of ultrasound in a total of 921 boys and girls 6-16 years of age are reported. The thyroid volume was found to be increasing slowly between the age of 6 and 12 years, but somewhat more remarkable increase occurred at 13 and 14 years of age. However, in both sexes it was nearly doubled at the age of 15-16 years as compared with the values at 13-14 years irrespective of body weight. The thyroid growth rate (as calculated from the least squares analysis of the correlation between thyroid volume and body weight) in girls was significantly higher (P less than 0.001) than in boys. In spite of long-term mandatory iodine prophylaxis the average urinary excretion of iodine as estimated in 69 randomly selected subjects was 78.06 micrograms/g creatinine (geometrical mean). It may be suggested that such intake of iodine, though marginally deficient, may be satisfactory up to the age of about 12-14 years, while it appeared to be inadequate for the adolescents at the age of puberty.