title: Endothelial progenitor cell number and colony-forming capacity in overweight and obese adults.
abstract: OBJECTIVE
  To investigate whether adiposity influences endothelial progenitor cell (EPC) number and colony-forming capacity.
  
  
  METHODS
  Cross-sectional study of normal weight, overweight and obese adult humans.
  
  
  METHODS
  Sixty-seven sedentary adults (aged 45-65 years): 25 normal weight (body mass index (BMI) <or=25 kg/m(2); 12 males/13 females); 18 overweight (BMI=25-29.9 kg/m(2); 12 males/6 females); and 24 obese (BMI >or=30 kg/m(2); 18 males/6 females). All participants were non-smokers and free of overt cardiometabolic disease.
  
  
  METHODS
  Peripheral blood samples were collected and circulating EPC number was assessed by flow cytometry. Putative EPCs were defined as CD45(-)/CD34(+)/VEGFR-2(+)/CD133(+) or CD45(-)/CD34(+) cells. EPC colony-forming capacity was measured in vitro using a colony-forming unit (CFU) assay.
  
  
  RESULTS
  Number of circulating putative EPCs (either CD45(-)/CD34(+)/VEGFR-2(+)/CD133(+) or CD45(-)/CD34(+) cells) was lower (P<0.05) in obese (0.0007+/-0.0001%; 0.050+/-0.006%) compared with overweight (0.0016+/-0.0004%; 0.089+/-0.019%) and normal weight (0.0015+/-0.0003%; 0.082+/-0.008%) adults. There were no differences in EPC number between the overweight and normal weight groups. EPC colony formation was significantly less in the obese (6+/-1) and overweight (4+/-1) compared with normal weight (9+/-2) adults.
  
  
  CONCLUSIONS
  These results indicate that: (1) the number of circulating EPCs is lower in obese compared with overweight and normal weight adults; and (2) EPC colony-forming capacity is blunted in overweight and obese adults compared with normal weight adults. Impairments in EPC number and function may contribute to adiposity-related cardiovascular risk.
authors.affiliation: Integrative Vascular Biology Laboratory, Department of Integrative Physiology, University of Colorado, Boulder, CO 80309, USA.
authors.forename: O J
authors.initials: OJ
authors.lastname: MacEneaney
authors.forename: E J
authors.initials: EJ
authors.lastname: Kushner
authors.forename: G P
authors.initials: GP
authors.lastname: Van Guilder
authors.forename: J J
authors.initials: JJ
authors.lastname: Greiner
authors.forename: B L
authors.initials: BL
authors.lastname: Stauffer
authors.forename: C A
authors.initials: CA
authors.lastname: DeSouza
mesh_terms: D000368:Aged; D015992:Body Mass Index; D002452:Cell Count; D003114:Colony-Forming Units Assay; D003430:Cross-Sectional Studies; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000473:pathology*; D050177:Overweight / Q000473:pathology; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*