INS and metabolic syndrome: Basic index analysis showed that compared with the C57BL/6J control group (NC group), KKAy mice showed remarkable metabolic abnormalities (P<0.01), including: accelerated body weight gain (Figure 2A), decreased serum 25(OH)D concentrations (Figure 2B), elevated FBG levels (Figure 2C), impaired glucose tolerance (Figures 2D–F), hyperinsulinemia evidenced by increased fasting insulin and HOMA-IR (Figures 2G, H), and dyslipidemia manifested by altered TC, LDL-C, and HDL-C levels (Figures 2J–L).