title: Vascular dysfunction and reduced circulating endothelial progenitor cells in young healthy UK South Asian men.
abstract: OBJECTIVE
  The objective of this study was to examine determinants of excess coronary artery disease risk in UK South Asians, more prevalent in this population than UK Caucasians, by examining differences in risk factors, vascular function, and endothelial progenitor cells (EPCs).
  
  
  RESULTS
  24 South Asian and 25 Caucasian healthy age-matched nonsmoking men were studied. Vascular function was assessed by flow-mediated and GTN brachial artery dilatation and blood flow responses to infusion of ACh, SNP, and L-NMMA. EPC number and function were measured by flow cytometry (CD34, CD133, and KDR positive cells), and CFU/migration assays. Traditional risk factors and anthropometric measurements were similar in the groups. South Asians had higher fasting insulin levels (6.01 versus 3.62 microU/mL; P = 0.02). South Asians had lower FMD (6.9 versus 8.5%; P = 0.003), L-NMMA response (0.8 versus 1.3 mL/min/100 mL; P = 0.03), mean SNP response (9.5+/-0.6 versus 11.6+/-0.6; P = 0.02), EPC number (0.046+/-0.005% versus 0.085+/-0.009%; P = < 0.001), and CFU ability (CFU 4.29+/-1.57 versus 18.86+/-4.00; P = 0.005). EPC number was the strongest predictor of FMD. Ethnicity was the strongest predictor of EPC number.
  
  
  CONCLUSIONS
  Healthy South Asian men are more insulin resistant, and demonstrate endothelial dysfunction and reduced EPC number and function compared with Caucasians. These abnormalities may contribute to their increased CAD risk.
authors.affiliation: Cardiovascular Division, Kings College London, London, UK.
authors.forename: Cliona
authors.initials: C
authors.lastname: Murphy
authors.forename: Gajen S
authors.initials: GS
authors.lastname: Kanaganayagam
authors.forename: Benyu
authors.initials: B
authors.lastname: Jiang
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Chowienczyk
authors.forename: Rainer
authors.initials: R
authors.lastname: Zbinden
authors.forename: Mrinal
authors.initials: M
authors.lastname: Saha
authors.forename: Salman
authors.initials: S
authors.lastname: Rahman
authors.forename: Ajay M
authors.initials: AM
authors.lastname: Shah
authors.forename: Michael S
authors.initials: MS
authors.lastname: Marber
authors.forename: Mark T
authors.initials: MT
authors.lastname: Kearney
mesh_terms: D000328:Adult; D000886:Anthropometry; D044466:Asian People; D001769:Blood; D001808:Blood Vessels / Q000503:physiopathology*; D002452:Cell Count; D003324:Coronary Artery Disease / Q000208:ethnology / Q000209:etiology*; D042783:Endothelial Cells / Q000473:pathology*; D015444:Exercise; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D012044:Regression Analysis; D018570:Risk Assessment; D013234:Stem Cells / Q000473:pathology*; D006113:United Kingdom / Q000208:ethnology