INS and Insulin resistance: Next, we conducted correlation analysis, and the results showed that NGF was not only positively associated with fasting (P = 0.007), 1-h (P < 0.001) and 2-h glucose levels (P < 0.001) and AUCG values (P < 0.001), but also positively related to insulin resistance and pancreatic β cell function, as shown by fasting insulin (P < 0.001) HOMA-IR (P < 0.001) and HOMA-β (P = 0.043) (Fig. 2).