IGFBP3 and precocious puberty: Some studies prompted that elevated IGF-1 and IGFBP-3 levels commonly decrease after central puberty suppression [4, 6, 11, 15], while others considered that gonadotropin-releasing hormone agonist therapy has no significant effect on IGF-1 or IGFBP-3 levels in patients with central precocious puberty [4–8, 16, 17].