SHBG and Insulin resistance: Decreased brain and muscle ARNT-like protein 1 (BMAL1) contributes to insulin resistance via glucose transporter 4 (GLUT4), and a reduction in period (PER) 1 and PER2 promotes androgen excess via insulin-like growth factor-binding protein 4 (IGFBP4) and sex hormone-binding globulin (SHBG) in the liver.