title: High incidence of insulin resistance and dysglycemia amongst nondiabetic cardiac surgical patients.
abstract: BACKGROUND
  Undiagnosed glycometabolic dysfunction is prominent amongst nondiabetic cardiac surgical patients, whereas perioperative dysglycemia is associated with adverse outcomes. This study assessed whether the preoperative level of insulin resistance predicts the degree of perioperative dysglycemia in nondiabetic, normoglycemic cardiac surgical patients.
  
  
  METHODS
  Twenty-two nondiabetic patients awaiting cardiac operations were assessed for metabolic parameters and whole-body insulin resistance (mean glucose infusion [GINF] rate) using the hyperinsulinemic-euglycemic clamp. Intraoperative and postoperative glucose levels and treatment requirements were analyzed. Linear regression analysis was used to find predictors of baseline, peak intraoperative, and mean postoperative fasting blood glucose (FBG).
  
  
  RESULTS
  The mean GINF recorded in nondiabetic, normoglycemic patients was 3.5 ± 1.4 mg/kg/min. The mean peak intraoperative and mean postoperative FBG concentrations were 154.9 ± 34.2 mg/dL (range, 108.1 to 227.0 mg/dL) and 120.7 ± 16.2 mg/dL (range, 100.9 to 154.9 mg/dL), respectively. The GINF correlated inversely with mean peak intraoperative (r = -0.7, p = 0.02) and mean postoperative FBG (r = -0.8, p = 0.01). The GINF did not correlate with preoperative FBG levels (r = 0.3, p = 0.4). Preoperative FBG did not correlate with peak intraoperative (r = 0.4, p = 0.5) or mean postoperative FBG (r = 0.5, p = 0.3).
  
  
  CONCLUSIONS
  Nondiabetic, normoglycemic cardiac surgical patients are highly insulin resistant using the hyperinsulinemic-euglycemic clamp. Preoperative insulin resistance, not FBG, is significantly associated with the development of perioperative dysglycemia. Insulin resistance screening may be useful to identify insulin resistance preoperatively and predict the degree of perioperative dysglycemia in cardiac surgical patients but should be performed with a more appropriate and reproducible test.
authors.affiliation: Department of Medicine (St. Vincent's), The University of Melbourne, Melbourne, Victoria, Australia. s.hofferberth@ugrad.unimelb.edu.au
authors.forename: Sophie C
authors.initials: SC
authors.lastname: Hofferberth
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Newcomb
authors.forename: Marno C
authors.initials: MC
authors.lastname: Ryan
authors.forename: Michael Y
authors.initials: MY
authors.lastname: Yii
authors.forename: Ian K
authors.initials: IK
authors.lastname: Nixon
authors.forename: Alexander
authors.initials: A
authors.lastname: Rosalion
authors.forename: Raymond C
authors.initials: RC
authors.lastname: Boston
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Ward
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Wilson
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D005215:Fasting / Q000378:metabolism; D005260:Female; D006801:Humans; D015994:Incidence; D007333:Insulin Resistance; D016014:Linear Models; D008297:Male; D008875:Middle Aged
chemical_list: D001786:Blood Glucose