GH1 and Gonadotropin deficiency: The administration of high doses of sex steroids before the last evaluation to the patients with gonadotropin deficiency, to obtain levels similar to those of group 1, would help to confirm the absence of a direct affect of sex steroids on IGF I. However, one patient from group 1 (case 3) and two from group 2 (cases 10 and 15) with similar plasma testosterone concentrations (spontaneously or after administration) but different GH peaks (3 and 0 ng/ml) had different plasma IGF I concentrations (296 vs 59 and 78 ng/ml).