title: Effects of acute exercise on circulating endothelial and progenitor cells in children and adolescents with juvenile idiopathic arthritis and healthy controls: a pilot study.
abstract: BACKGROUND
  Youth with juvenile idiopathic arthritis (JIA) may be at risk of poor cardiovascular health. Circulating endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) are markers of cardiovascular repair and damage, respectively, and respond to exercise. The objectives of this study were to compare resting levels of EPCs and CECs in JIA and controls, and to assess the effects of distinct types of exercise on EPCs and CECs in JIA and controls.
  
  
  METHODS
  Seven youth with JIA and six controls completed 3 visits. First, aerobic fitness was assessed. Participants then performed either moderate intensity, continuous exercise (MICE) or high intensity, intermittent exercise (HIIE) on separate days. Blood samples were collected at the beginning (REST), mid-point (MID) and end of exercise (POST) for determination of EPCs (CD31(+)CD34(bright)CD45(dim)CD133(+)) and CECs (CD31(bright)CD34(+)CD45(-)CD133(-)) by flow cytometry. Between group differences in EPCs and CECs were examined using two-way ANOVA, followed by Tukey's HSD post hoc, where appropriate. Statistical significance set at p ≤ 0.05.
  
  
  RESULTS
  Both EPCs and CECs were similar between groups at REST (p = 0.18-0.94). During MICE, EPCs remained unchanged in JIA (p = 0.95) but increased significantly at POST in controls (REST: 0.91 ± 0.55 × 10(6) cells/L vs. POST: 1.53 ± 0.36 × 10(6) cells/L, p = 0.04). Compared with controls, lower levels of EPCs were observed in JIA at MID (0.48 ± 0.50 × 10(6) cells/L vs. 1.10 ± 0.39 × 10(6) cells/L, p = 0.01) and POST (0.38 ± 0.34 × 10(6) cells/L vs. 1.53 ± 0.36 × 10(6) cells/L, p < 0.001) during MICE. No changes were detected in CECs with MICE in JIA and controls (p = 0.69). Neither EPCs nor CECs were modified with HIIE (p = 0.28-0.69).
  
  
  CONCLUSIONS
  Youth with JIA demonstrated a blunted EPC response to MICE when compared with controls. Future work should examine factors that may increase or normalize EPC mobilization in JIA.
authors.affiliation: Child Health and Exercise Medicine Program, McMaster University, HSC 3N27G, 1280 Main Street West, Hamilton, L8S 4K1, ON, Canada. obeidj@mcmaster.ca.|Department of Pediatrics, McMaster University, 1280 Main St W, Health Sciences Centre, Hamilton, L8S 4K1, ON, Canada. obeidj@mcmaster.ca.
authors.forename: Joyce
authors.initials: J
authors.lastname: Obeid
authors.affiliation: Child Health and Exercise Medicine Program, McMaster University, HSC 3N27G, 1280 Main Street West, Hamilton, L8S 4K1, ON, Canada. nguyet54@mcmaster.ca.|Department of Pediatrics, McMaster University, 1280 Main St W, Health Sciences Centre, Hamilton, L8S 4K1, ON, Canada. nguyet54@mcmaster.ca.
authors.forename: Thanh
authors.initials: T
authors.lastname: Nguyen
authors.affiliation: Department of Pediatrics, Division of Rheumatology, McMaster University, 1280 Main St W, Health Sciences Centre, Hamilton, L8S 4K1, ON, Canada. celluct@mcmaster.ca.|Department of Pediatrics, McMaster University, 1280 Main St W, Health Sciences Centre, Hamilton, L8S 4K1, ON, Canada. celluct@mcmaster.ca.
authors.forename: Tania
authors.initials: T
authors.lastname: Cellucci
authors.affiliation: Departments of Medicine and Pediatrics, Division of Rheumatology, McMaster University, Hamilton, ON, Canada. mlarche@mcmaster.ca.|Department of Medicine, Charlton Medical Centre, 25 Charlton Ave E, Suite 702, Hamilton, L8N1Y2, ON, Canada. mlarche@mcmaster.ca.
authors.forename: Maggie J
authors.initials: MJ
authors.lastname: Larché
authors.affiliation: Child Health and Exercise Medicine Program, McMaster University, HSC 3N27G, 1280 Main Street West, Hamilton, L8S 4K1, ON, Canada. timmonbw@mcmaster.ca.|Department of Pediatrics, McMaster University, 1280 Main St W, Health Sciences Centre, Hamilton, L8S 4K1, ON, Canada. timmonbw@mcmaster.ca.
authors.forename: Brian W
authors.initials: BW
authors.lastname: Timmons
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002648:Child; D066026:Endothelial Progenitor Cells / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D010865:Pilot Projects
chemical_list: D015415:Biomarkers