IGF1 and hyperinsulinism: Interestingly, rapid weight gain and growth in early childhood (reflecting good nutritional environment) may induce a childhood endocrine milieu where hyperinsulinism, elevated IGF-1, enhanced adrenal androgen secretion, increased peripheral metabolism of these weak androgens, and lower SHBG concentrations (leading to increased free androgen concentrations) could all promote pulsatile gonadotropin-releasing hormone activity (33).