ObjectiveTo study the correlation of postoperative cognitive dysfunction (POCD) with type-2 diabetes and glycosylated hemoglobin (HbA1c) levels in elderly patients. MethodsA total of 140 elderly patients who were going to undergo non-cardiothoracic surgery in our hospital between January 2011 and February 2013 were included in this study.ASA classification was between I and Ⅲ.There were 78 males and 62 females,aged between 65 and 86 years old.Group A had 70 patients with diabetes,while group B had another 70 corresponding patients without diabetes.One day before surgery and a week after surgery,Mini-mental State Examination (MMSE) and Montreal Cognitive Functioning Scale (MoCA) were used to test patients'cognitive function,and the incidence of POCD was compared between the two groups.Group A patients,according to HbA1c levels,were divided into group AH (HbA1c>7.5%) and group AL (HbA1c<7.5%).And we compared the relationship between group AL and group B,and the relationship between group AH and group B. ResultsThe incidence of POCD in group A was significantly higher than that in group B (P<0.05).Group AH had a significantly higher incidence of POCD than group AL (P<0.05).No significant difference was found in fasting plasma glucose among the groups. ConclusionElderly diabetic patients with poor glycemic control is a risk factor for POCD occurrence,but fasting glucose as a predictor of POCD is not as good as HbA1C.