title: Bone-marrow derived progenitor cells are associated with psychosocial determinants of health after controlling for classical biological and behavioral cardiovascular risk factors.
abstract: BACKGROUND
  Circulating progenitor cells have been implicated with maintaining vascular integrity. Low counts are found in adults with high cardiovascular risk and are associated with impaired endothelial function. It remains unknown whether psychosocial risk factors are independently related to counts of circulating progenitor cells.
  
  
  METHODS
  We investigated a random sample of 468 adult industrial employees (mean age 41.2 years, 89% men) of Caucasian origin. Cardiovascular risk factors (blood pressure, LDL, HDL and C-reactive protein), health behavior (smoking, alcohol and physical exercise), psychological variables (effort-reward imbalance social support, negative affectivity) and interaction terms served as predictors of circulating progenitor cells (CD34+ CD31dim) as enumerated by flow-cytometry.
  
  
  RESULTS
  Psychosocial variables were independently associated with progenitor cell counts. The association with risk factors increased with age (explained variance in 18-36 year olds R(2)=0.17, p=0.55; age 36.1-46 R(2)=0.32, p=0.001; age>46 R(2)=0.27, p<0.001). Data revealed a shift from a larger association between behavioral and psychosocial variables and cell counts to a stronger association between biological variables and cell counts in older individuals. A significant interaction was observed between smoking and effort-reward imbalance in middle-aged subjects, those with both risk factors present had lower cell counts. In older employees, the interaction between biological risk factors and smoking was related to lower cell counts.
  
  
  CONCLUSIONS
  In working middle-aged and older men, psychosocial risk factors were related to circulating counts of progenitor cells. Smoking interacted negatively with psychosocial risk factors (middle-aged men) or with biological risk factors (older employees).
authors.affiliation: Institute for Transplantation Diagnostics and Cell Therapeutics, University Hospital, Duesseldorf 40225, Germany.
authors.forename: Johannes C
authors.initials: JC
authors.lastname: Fischer
authors.forename: Brigitte M
authors.initials: BM
authors.lastname: Kudielka
authors.forename: Roland
authors.initials: R
authors.lastname: von Känel
authors.forename: Johannes
authors.initials: J
authors.lastname: Siegrist
authors.forename: Julian F
authors.initials: JF
authors.lastname: Thayer
authors.forename: Joachim E
authors.initials: JE
authors.lastname: Fischer
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001794:Blood Pressure / Q000502:physiology; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000503:physiopathology; D002452:Cell Count; D008078:Cholesterol, LDL / Q000502:physiology; D042783:Endothelial Cells / Q000502:physiology; D005260:Female; D005434:Flow Cytometry; D015438:Health Behavior; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D012307:Risk Factors; D012907:Smoking; D012944:Social Support; D013234:Stem Cells / Q000502:physiology*; D011795:Surveys and Questionnaires
chemical_list: D008078:Cholesterol, LDL; D002097:C-Reactive Protein