title: Endothelial progenitor cell mobilization by preoperative exercise: a bone marrow response associated with postoperative outcome.
abstract: BACKGROUND
  Preoperative anaemia is associated with increased morbidity in patients undergoing major surgery. Whether erythrocytes are the only bone-marrow-derived cell lineage that associates with increased surgical complications is unknown. This prospective observational trial studied the mobilization of endothelial progenitor cells (EPCs) in response to exercise in association with postoperative complications.
  
  
  METHODS
  After IRB approval, 60 subjects undergoing major thoracic surgery were exercised to exhaustion (peak V̇(O₂)). Peripheral blood collected before and after peak exercise was quantified for EPC lineages by fluorescence-activated cell sorter analysis. Complication analysis was based on the Clavien-Dindo classification.
  
  
  RESULTS
  Exhaustive exercise increased EPC [CD45-133+34+ cells=150 (0.00-5230) to 220 (0.00-1270) cells μl(-1); median change (range)=20 (-4,180-860) cells μl(-1); P=0.03] but not mature endothelial cell (EC) subpopulations. Pre-exercise levels [odds ratio (OR)=0.86, 95% confidence interval (CI): 0.37-2.00, P=0.72), change after exercise as a continuous variable (OR=0.95, 95% CI: 0.41-2.22, P=0.91) and a positive response after exercise (change >0 cells μl(-1); OR=0.41, 95% CI: 0.13-1.28, P=0.12) were not statistically significantly associated with the incidence of postoperative complications. Post-hoc receiver operating characteristic curve analyses revealed that subjects with a CD45-133+34+ increase ≥60 cells μl(-1) in response to exercise suffered fewer postoperative complications [86% sensitivity, 48% specificity and AUC=0.67 (95% CI: 0.52-0.81)].
  
  
  CONCLUSIONS
  Preoperative exercise induces EPC into the peripheral circulation. Subjects with a poor EPC response had a pre-existing propensity for postoperative complications. This warrants further research into the role of bone marrow function as a critical component to endothelial repair mechanisms.
  
  
  BACKGROUND
  IRB 2003-0434 (University of Texas M.D. Anderson Cancer Center, Houston, TX, USA).
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Cologne, Cologne, Germany robert.schier@gmx.net.
authors.forename: R
authors.initials: R
authors.lastname: Schier
authors.affiliation: Department of Epidemiology.
authors.forename: R
authors.initials: R
authors.lastname: El-Zein
authors.affiliation: Department of Epidemiology.
authors.forename: A
authors.initials: A
authors.lastname: Cortes
authors.affiliation: Department of Epidemiology.
authors.forename: M
authors.initials: M
authors.lastname: Liu
authors.affiliation: Centre for Biostatistics and Clinical Trials and.
authors.forename: M
authors.initials: M
authors.lastname: Collins
authors.affiliation: Department of Pediatrics I, University Children's Heidelberg, Heidelberg, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Rafat
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Hospital of Osnabrueck, Osnabrueck, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Teschendorf
authors.affiliation: Department of Thoracic/Head and Neck Oncology, and.
authors.forename: Hua-Kang
authors.initials: HK
authors.lastname: Wu
authors.affiliation: Department of Thoracic/Head and Neck Oncology, and.
authors.forename: J
authors.initials: J
authors.lastname: Heymach
authors.affiliation: Department of Thoracic Surgery, The University of Texas, M. D. Anderson Cancer Center, Houston, TX, USA.
authors.forename: R
authors.initials: R
authors.lastname: Mehran
authors.affiliation: Department of Cancer Anaesthetics and Pain Medicine, Peter MacCallum Cancer Centre, University of Melbourne, Melbourne, Australia.
authors.forename: B
authors.initials: B
authors.lastname: Riedel
mesh_terms: D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis; D001853:Bone Marrow / Q000502:physiology; D042783:Endothelial Cells / Q000502:physiology*; D023381:Endpoint Determination; D005006:Ethnicity; D005080:Exercise Test; D005081:Exercise Therapy / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D005434:Flow Cytometry; D019650:Hematopoietic Stem Cell Mobilization; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control*; D057234:Preoperative Period; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D012307:Risk Factors; D013312:Stress, Physiological; D019616:Thoracic Surgical Procedures; D016896:Treatment Outcome
keywords: training; vascular