Application of endogenous orphin as serum biomarker for diabetes mellitus complicated with asymptomatic myocardial ischemia

The invention belongs to the technical field of medicines, and provides application of endogenous orphin, namely N/OFQ, as a serum biomarker for diabetes mellitus complicated with asymptomatic myocardial ischemia in order to solve the problem that effective indexes which can be directly detected from blood do not exist in the existing definite diagnosis of the asymptomatic myocardial ischemia SMI. The invention discloses application of endogenous orphin. The endogenous orphin is used for preparing a diagnostic reagent or a kit for detecting diabetes mellitus complicated with asymptomatic myocardial ischemia. The serum N/OFQ in the body of a patient with diabetes mellitus combined with SMI is obviously increased and is positively correlated with the severity degree of coronary artery lesions, so that the N/OFQ is determined to possibly become a potential index for predicting SMI. In view that N/OFQ can play a role in acute myocardial ischemia, N/OFQ becomes possible to serve as a new index for predicting the c