HG also aggravated diabetic myocardial fibrosis by increasing the expression levels of type III collagen, MMP-8, MMP-13 and MMP-14 in the diabetic myocardium and inhibited autophagy by downregulating the expression levels of autophagy-related proteins including Atg5, Atg16L1 and Beclin1 in HG-induced H9C2. The gene discussed is ATG5; the disease is diabetes mellitus.