IGFBPL1 and obesity due to melanocortin 4 receptor deficiency: <h4>Background</h4>Insulin-like growth factor binding protein-1 (IGFBP-1) is considered a decline in polycystic ovary syndrome (PCOS), but it remains controversial that whether such reduction is attributed to obesity.<h4>Aims</h4>This systematic review aims to explore whether IGFBP-1 is reduced in PCOS, and whether such reduction is associated with obesity.<h4>Results</h4>Our pooled study included 12 studies with a total of 450 participants.