FGF21 and Insulin resistance: Muscle FGF-21 mRNA correlated positively to all markers of insulin resistance: fasting insulin (r = 0.57, p = 0.0008), homeostasis model assessment (HOMA) score (r = 0.55, p = 0.001), and insulinAUC (r = 0.38, p = 0.02) (Fig. 1 C–F).