title: Interleukin 6 production during cardiac surgery correlates with increasing age.
abstract: BACKGROUND
  Cardiac surgery produces a proinflammatory response characterized by cytokine production. Proinflammatory cytokines such as interleukin 6 (IL-6) may contribute to morbidity and mortality after cardiopulmonary bypass (CPB). Elderly patients undergoing CPB are at increased risk of morbidity and mortality. We hypothesized that patients aged >70 y produce more IL-6 during CPB.
  
  
  METHODS
  Twenty-three patients (ages 23-80) undergoing cardiac surgery had blood sampled from the ascending aorta and coronary sinus on initial cannulation for bypass, at 30 min of aortic cross-clamp time, on release of the aortic cross-clamp, and at 20 min after reperfusion. Group 1 patients (n = 8) were aged <60 y, group 2 patients (n = 7) were aged between 60 and 70 y, and group 3 patients (n = 8) were aged >70 y. Plasma levels of tumor necrosis factor-alpha, IL-1, and IL-6 were analyzed.
  
  
  RESULTS
  The three groups did not differ with respect to preoperative ejection fraction, New York Heart Association classification, mean aortic cross-clamp time, or mean CPB time. IL-6 levels rose throughout myocardial ischemia and reperfusion in all three age groups. The increase in IL-6 during ischemia and reperfusion in the age group >70 was greater than the increase in younger patients. IL-6 was similar in the coronary sinus and the ascending aorta.
  
  
  CONCLUSIONS
  These data suggest that patients aged >70 y undergoing cardiac operations generate more IL-6 during CPB. The increased circulating IL-6 in elderly patients may incite a proinflammatory state that could subsequently underlie the associated higher mortality and morbidity of these procedures in elderly patients.
authors: Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors: Kenneth W
authors: KW
authors: Howell
authors: Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado. Electronic address: joseph.cleveland@ucdenver.edu.
authors: Joseph C
authors: JC
authors: Cleveland
authors: Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors: Xianzhong
authors: X
authors: Meng
authors: Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors: Lihua
authors: L
authors: Ao
authors: Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors: Xin
authors: X
authors: Su
authors: Division of Geriatric Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors: Robert S
authors: RS
authors: Schwartz
authors: Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors: David A
authors: DA
authors: Fullerton
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D001011:Aorta; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D054326:Coronary Sinus; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008875:Middle Aged; D011446:Prospective Studies; D055815:Young Adult
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6
keywords: CAB surgery; Cardiac surgery; Cardiopulmonary bypass; Elderly (>70 y); IL-6; Inflammatory mediators