Inflammatory response and postoperative kidney failure in patients with diabetes type 2 or impaired glucose tolerance undergoing heart valve surgery.

BACKGROUND Diabetes type 2 (DM) or impaired glucose tolerance (IGT) are linked with a 3-fold increased risk of renal failure after heart valve surgery. The increase of proinflammatory cytokines is detected in patients with DM or IGT, moreover cardiac surgery promotes the proinflammatory response, which may be responsible for the development of postoperative kidney failure. AIM To assess the impact of perioperative pro- and antiinflammatory reaction after heart valve surgery and other clinical parameters on the risk of postoperative acute kidney injury in patients with DM or IGT. METHODS Thirty patients with DM or IGT, without fibrate or statin treatment, with a mean LDL-cholesterol below 129 mg/dL, ejection fraction > 45%, in NYHA class II and III, referred for surgery due to acquired heart valve disease entered the study. Patients with acute or chronic inflammatory conditions, coronary artery disease or creatinine clearance below 50 mL/min were excluded. Serum creatinine, glycosylated hemoglobin, LDL-cholesterol and interleukin-10 as well as TNF-alpha were assessed before surgery. Interleukin-10 and TNF-alpha were also measured 4 hours after weaning from cardiopulmonary bypass. Moreover, serum creatinine and hemoglobin were measured 18 +/- 2 hours after surgery. The relationship between postoperative creatinine clearance, its postoperative change and other parameters was assessed. These parameters included: age, weight and body mass index, pre- and postoperative serum level of TNF-alpha and interleukin-10, preoperative concentration of LDL-cholesterol and glycosylated hemoglobin, duration of cardiopulmonary bypass and postoperative hemoglobin. RESULTS The significant postoperative decrease of creatinine clearance was noted in the study group. Eight (27%) patients developed postoperative kidney failure, of them 2 (6.5%) patients required hemodialysis. The level of TNF-alpha and interleukin-10 increased significantly postoperatively. A significant correlation between duration of cardiopulmonary bypass and postoperative decrease of creatinine clearance was noted (R = 0.43, p = 0.02). A non-significant trend towards correlation between preoperative TNF-alpha and postoperative decrease of creatinine clearance was observed (R = -0.36, p = 0.05). CONCLUSIONS Postoperative kidney failure with the incidence of 27% is a frequent finding in patients with DM or IGT operated due to acquired heart valve disease. The postoperative proinflammatory response is not involved in the development of this complication. The correlation between postoperative decrease of creatinine clearance and duration of cardiopulmonary bypass was noted. The trend toward the link between postoperative kidney failure and preoperative proinflammatory status was seen.