INS and gestational diabetes: Leptin, often elevated in GDM, inhibits insulin receptor expression through janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways, while hypoadiponectinemia reduces adenosine monophosphate (AMP)-activated protein kinase (AMPK) activity, further impairing GLUT4 activation and insulin sensitivity [10,42,43].