We mainly collected plasma from clinical patients to measure the expression of lncRNA‐MEG3, and explored the molecular mechanism of lncRNA‐MEG3 in CIRI combined with DM by immunofluorescence, western blot, co‐ip and other molecular biology experiments in rat MACO+DM model and cellular OGD/R+HG model. The gene discussed is MEG3; the disease is diabetes mellitus.