Preoperative depression is a risk factor for postoperative short-term and long-term cognitive dysfunction in patients with diabetes mellitus

Purpose To identify whether the presence of preoperative depression in patients with diabetes mellitus is a risk factor for postoperative cognitive dysfunction after coronary artery bypass graft (CABG) surgery. Methods Data from 90 patients with diabetes mellitus undergoing elective CABG were analyzed. Hemodynamic data (arterial and jugular venous blood gas values) were measured during cardiopulmonary bypass. Preoperatively, all patients were given the 21-item Beck depression inventory to identify the presence of depression. In addition, all patients underwent a battery of neurological and neuropsychological tests the day before surgery, 7 days after surgery, and 6 months after surgery. Results The rate of cognitive dysfunction was 50% at 7 days and 23% at 6 months after surgery. Age, hypertension, presence of depression, duration of SjvO(2) <= 50%, ascending aorta atherosclerosis, diabetic retinopathy, and insulin therapy were independent predictors of short-term cognitive dysfunction, whereas HbA1c, diabetic retinopathy, insulin therapy, and presence of depression were independent predictors of long-term cognitive dysfunction. Conclusions We found that the presence of depression preoperatively is associated with short-term and long-term postoperative cognitive dysfunction in patients with diabetes mellitus.