Figure 6. Schematic representation of the interactions between the hypothalamic-pituitary-adrenal (HPA) axis and the reproductive and growth axes. Chronic hyperactivation of the stress system may lead to both osteoporosis and metabolic syndrome. CRH: corticotropin-releasing hormone; GnRH: gonadotropin-releasing hormone; ACTH: adrenocorticotropic hormone (corticotrophin); LH: luteinizing hormone; FSH: follicle-stimulating hormone; GHRH: growth hormone releasing hormone; STS: somatostatin; GH: growth hormone; SmC: somatomedin C. Activation is represented by solid green lines and inhibition by dashed red lines.