title: Pyruvate Dehydrogenase Activity and Quantity Decreases After Coronary Artery Bypass Grafting: a Prospective Observational Study.
abstract: BACKGROUND
  Pyruvate dehydrogenase (PDH) is a key gatekeeper enzyme in aerobic metabolism. The main purpose of this study was to determine if PDH activity is affected by major stress in the form of coronary artery bypass grafting (CABG), which has previously been used as a model of critical illness.
  
  
  METHODS
  We conducted a prospective, observational study of patients undergoing CABG at an urban, tertiary care hospital. We included adult patients undergoing CABG with or without concomitant valve surgery. Measurements of PDH activity and quantity and thiamine were obtained prior to surgery, at the completion of surgery, and 6 h after surgery.
  
  
  RESULTS
  Fourteen patients were enrolled (aged 67 ± 10 years, 21% female). Study subjects had a mean 41.7% (SD, 27.7%) reduction in PDH activity after surgery and a mean 32.0% (SD, 31.4%) reduction 6h after surgery (P < 0.001). Eight patients were thiamine deficient (≤ 7 nmol/L) after surgery compared with none prior to surgery (P = 0.002). Thiamine level was significantly associated with PDH quantity at all time points (P = 0.01). Postsurgery lactate levels were inversely correlated with postsurgery thiamine levels (r = -0.58 and P = 0.04).
  
  
  CONCLUSIONS
  The stress of major surgery causes decreased PDH activity and quantity and depletion of thiamine levels.
authors.affiliation: *Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts; †Department of Anesthesiology, Aarhus University Hospital, Aarhus, Denmark; and ‡Division of Cardiothoracic Surgery and §Division of Pulmonary and Critical Care Medicine, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts.
authors.forename: Lars W
authors.initials: LW
authors.lastname: Andersen
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Liu
authors.forename: Teng J
authors.initials: TJ
authors.lastname: Peng
authors.forename: Tyler A
authors.initials: TA
authors.lastname: Giberson
authors.forename: Kamal R
authors.initials: KR
authors.lastname: Khabbaz
authors.forename: Michael W
authors.initials: MW
authors.lastname: Donnino
mesh_terms: D000368:Aged; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011768:Pyruvate Dehydrogenase Complex / Q000097:blood*; D013312:Stress, Physiological; D013831:Thiamine / Q000097:blood
chemical_list: D011768:Pyruvate Dehydrogenase Complex; D019344:Lactic Acid; D013831:Thiamine