Objective To investigate the relationship of stress hyperglycemia,cystatin C and estimated glomerular filtration rate (eGFR) with short-term prognosis in elderly patients with acute myocardial infarction.Methods 242 consecutive patients with acute myocardial infarction were divided into two groups according to age:the elderly group (n=182),and the non elderly group (n=60).The clinical data including cystatin C (Cys C),eGFR and stress hyperglycemia levels were collected.The major adverse cardiovascular events (MACE) were observed during hospitalization and 30 days after discharge.Results The incidences of stress hyperglycemia,the levels of creatinine,Cys C and brain natriuretic peptide (BNP),as well as the total MACE were higher and eGFR was lower in elderly group than in non-elderly group (all P＜0.05).Cys C level was positively correlated with age,body mass index and levels of creatinine and BNP (all P＜0.05),and negatively correlated with fasting glucose and eGFR in elderly group (both P＜0.05).The eGFR was positively correlated with body mass index (P＜0.05),and negatively correlated with age,creatinine and BNP levels in elderly group (all P＜0.05).Logistic regression analysis indicated that stress hyperglycemia [OR=1.871,95％CI:1.071-3.269,P=0.03],Cys C [OR=7.093,95％CI:2.261-22.249,P=0.00] were the independent risk factors for MACE.Conclusions Cys C level and eGFR can predict the early renal dysfunction and its prognosis in elderly patients with acute myocardial infarction.The incidence of stress hyperglycemia is higher in the elderly,and stress hyperglycemia and Cys C level are the independent risk factors for MACE.