Assessment of physical maturation and somatomedin levels during puberty.

The chronologic age, skeletal age, and somatomedin level of thirty-nine Caucasian girls of various developmental stages were compared. The results showed that there was a significant difference between the somatomedin levels in the plasma of circumpubertal and postpubertal females. No significant difference was noted between the prepubertal and the circumpubertal subjects tested. In addition, the skeletal age appears to be a better indicator of physical maturation than does the chronologic age of an individual. In order to substantiate the concept of somatomedin as a true marker for the pubertal growth spurt, this study should be continued on a longitudinal basis utilizing rate-of-growth data.