Duan et al. [47] considered hyperglycemia led to enhancing oxidative stress that reduced free iron in circulation, with elevated hepcidin inhibiting the intestine absorbing Fe and release of Fe by the reticuloendothelial system; the correlation between serum Cr and serum Fe in IFG and IGT was not significant, but we still found the tendency existed. The gene discussed is HAMP; the disease is Hyperglycemia.