title: Exercise-induced endothelial progenitor cell mobilization is attenuated in impaired glucose tolerance and type 2 diabetes.
abstract: Circulating endothelial progenitor cells (EPCs) contribute to vascular homeostasis and are fewer in those with type 2 diabetes mellitus (T2DM) compared with normal glucose tolerance (NGT), suggesting a link between EPCs and T2DM-associated vasculopathies. The purpose of this study was to assess EPC number and mobilization by acute submaximal exercise in older adults with NGT, impaired glucose tolerance (IGT) or T2DM. We tested the hypothesis that EPC mobilization is lower in IGT compared with NGT and further reduced in older adults with T2DM. Forty-five older (50-75 yr of age) men and women with NGT (n = 18), IGT (n = 10), or T2DM (n = 17) were characterized and underwent submaximal aerobic exercise tests with blood sampling for enumeration of vascular endothelial growth factor receptor 2+ (VEGFR2+) cells, CD34+ hematopoetic progenitor cells, and CD34+/VEGFR2+ EPCs by flow cytometry before and after exercise. Basal EPC number was 65 and 61% lower in the IGT and T2DM groups, respectively, compared with the NGT group (P < 0.05). EPC number increased 23% after acute exercise in the NGT group (P < 0.01), but did not change in the IGT or T2DM groups. Before and after exercise, VEGFR2+ cell number was lower in a stepwise manner across the NGT, IGT, and T2DM groups (P < 0.05). Basal CD34+ cell number was lower in the IGT group compared with NGT (P < 0.05), but did not change after exercise in any group. These findings suggest a CD34+/VEGFR2+ EPC mobilization defect in IGT and T2DM that could play a role in the cardiovascular diseases and capillary rarefaction associated with insulin resistance.
authors.affiliation: Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Maryland School of Medicine and the Baltimore Veterans Affairs Geriatric Research, Education and Clinical Center, Baltimore, Maryland.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Lutz
authors.affiliation: Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Maryland School of Medicine and the Baltimore Veterans Affairs Geriatric Research, Education and Clinical Center, Baltimore, Maryland.
authors.forename: Jacob B
authors.initials: JB
authors.lastname: Blumenthal
authors.affiliation: Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Maryland School of Medicine and the Baltimore Veterans Affairs Geriatric Research, Education and Clinical Center, Baltimore, Maryland.
authors.forename: Rian Q
authors.identifier: 0000-0002-3092-2538
authors.initials: RQ
authors.lastname: Landers-Ramos
authors.affiliation: Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Maryland School of Medicine and the Baltimore Veterans Affairs Geriatric Research, Education and Clinical Center, Baltimore, Maryland sprior@grecc.umaryland.edu.
authors.forename: Steven J
authors.identifier: 0000-0002-4627-6489
authors.initials: SJ
authors.lastname: Prior
mesh_terms: D000368:Aged; D018952:Antigens, CD34 / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000503:physiopathology*; D066026:Endothelial Progenitor Cells / Q000378:metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D005947:Glucose / Q000378:metabolism; D018149:Glucose Intolerance / Q000378:metabolism / Q000503:physiopathology*; D005951:Glucose Tolerance Test / Q000379:methods; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: D018952:Antigens, CD34; D001786:Blood Glucose; D007328:Insulin; D040301:Vascular Endothelial Growth Factor Receptor-2; D005947:Glucose
keywords: cardiovascular disease; endothelial progenitor cells; exercise; type 2 diabetes mellitus