The Investigators continues to study the relationship between pubertal development and the secretion of and sensitivity to growth hormone. In adolescent boys and girls IGF-1 levels were found to be more dependent on sex hormone levels than on nocturnal growth hormone secretion. This difference was not dependent on puberty-related changes in the IGF binding proteins IGFBP-1, IGFBP-2, or IGFBP-3. This finding was presented at the Annual 1994 meeting of the Endocrine Society and is being prepared for publication.