title: The decrement in circulating endothelial progenitor cells (EPCs) in type 2 diabetes is independent of the severity of the hypoadiponectemia.
abstract: BACKGROUND
  Type 2 diabetes mellitus (DM) is associated with a decreased level of circulating endothelial progenitor cells (EPCs) and adiponectin. Experimental studies suggest a potential link between hypoadiponectinaemia and the depletion of the EPC level. This study investigated the relationships between adiponectin level and EPC in patients with type 2 DM.
  
  
  METHODS
  A total of 95 type 2 DM patients (58.5 ± 8.8 years, 42 men) and 95 age- and sex-matched healthy controls were recruited. Circulating EPC levels were determined by flow cytometry using CD133(+), CD34(+), CD133(+) /KDR(+) and CD34(+) /KDR(+) as surface markers. Plasma adiponectin levels were measured by enzyme-linked immunosorbent assay. EPC function was studied by in vitro tube formation and migration assay.
  
  
  RESULTS
  The levels of CD133(+) (p < 0.001) and CD133(+) /KDR(+) (p < 0.001) EPCs were independently associated with the presence of type 2 DM. The levels of CD34(+) (p = 0.004) and CD34(+) /KDR(+) (p = 0.013) EPCs were independently associated with haemoglobin A(1c). Nevertheless, there was no relationship between the number of EPCs and adiponectin level. Tube formation assay showed impaired pro-angiogenic function of EPC in DM patients compared with controls (p = 0.007). Interestingly, adiponectin supplementation (5 µg/mL) increased tube formation by 17.6% in EPCs from DM patients (p = 0.002). It also significantly enhanced cell migration by 35.9% in EPCs from DM patients (p = 0.01).
  
  
  CONCLUSIONS
  We detected no relationship between the reduction in the level of EPC and in the level of total adiponectin in blood from patients with type 2 diabetes. EPC from patients with diabetes were stimulated when exposed to adiponectin in the test tube, findings that warrant further study.
authors.affiliation: Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong.
authors.forename: Mingfang
authors.initials: M
authors.lastname: Li
authors.forename: Jenny C Y
authors.initials: JC
authors.lastname: Ho
authors.forename: Kevin W H
authors.initials: KW
authors.lastname: Lai
authors.forename: Karen K W
authors.initials: KK
authors.lastname: Au
authors.forename: Aimin
authors.initials: A
authors.lastname: Xu
authors.forename: Bernard M Y
authors.initials: BM
authors.lastname: Cheung
authors.forename: Karen S L
authors.initials: KS
authors.lastname: Lam
authors.forename: Hung-Fat
authors.initials: HF
authors.lastname: Tse
mesh_terms: D052242:Adiponectin / Q000097:blood*; D016022:Case-Control Studies; D002478:Cells, Cultured; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000473:pathology; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013234:Stem Cells / Q000378:metabolism*; D014471:Umbilical Veins / Q000166:cytology / Q000378:metabolism
chemical_list: D052242:Adiponectin