INS and Insulin resistance: Six studies measured the levels of fasting insulin (FINs) (Figure 3D; SMD: -22.72; 95% CI: [-36.79, -8.66], I2 = 99%, P=0.002), and five measured the homeostasis model assessment for insulin resistance (HOMA-IR) index (Figure 4A; SMD: -26.36; 95% CI: [-33.64, -19.08], I2 = 93%, P=0.01).