title: Circulating endothelial progenitor cells in type 1 diabetic patients with erectile dysfunction.
abstract: Circulating endothelial progenitor cells (EPCs) are bone marrow-derived stem cells able to migrate to sites of damaged endothelium and differentiate into endothelial cells, thereby contributing to vascular repair. Recent studies demonstrated a reduction of EPCs in patients with diabetes mellitus or erectile dysfunction (ED). The aim of this study was to evaluate the circulating levels of different EPCs phenotypes and their relation with testosterone levels in young type 1 diabetic patients with ED. We studied 118 consecutively type 1 diabetic patients and 60 age-matched healthy controls. Erectile function was assessed by completing the International Index of Erectile Function (IIEF-5) and EPCs levels by flow cytometry. Testosterone concentrations were evaluated in all the study population. We identified 38 diabetic patients with ED (Group 1) and 80 patients without ED (Group 2). CD34+KDR+CD133+ cells were significantly lower in patients in Group 1 as compared with those in Group 2 [median and interquartile range, n/10(6) events, 12 (6-16) vs. 18 (13-22), P < 0.001)]. In all participants in the study, there was a significant correlation between circulating CD34+KDR+CD133+ cells and testosterone levels (r = 0.410, P < 0.001), which was highest in Group 1, intermediate in Group 2, and lowest in Group 3 (controls). There was a significant correlation between IIEF-5 score and both CD34+KDR+ (r = 0.459, P = 0.003) and CD34+KDR+CD133+ (r = 0.316, P = 0.050) cells among patients of Group 1, as well as between testosterone levels and most of the EPCs phenotypes. Finally, multivariate regression analysis identified levels of circulating CD34+KDR+ cells as an independent risk factor for ED (β-coefficient 0.348, P = 0.007). In conclusion, type 1 diabetic patients with ED show reduced levels of CD34+KDR+CD133+ cells, whose number correlates with IIEF. Further studies are needed to fully understand the exact mechanisms by which testosterone regulates vascular homeostasis.
authors.affiliation: Endocrinology and Metabolic Diseases Unit, Department of Medical, Surgical, Neurological, Metabolic Science and Geriatrics, University Hospital at Second University of Naples, Piazza L. Miraglia n° 2, 80138, Naples, Italy, mariaida.maiorino@unina2.it.
authors.forename: Maria Ida
authors.initials: MI
authors.lastname: Maiorino
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bellastella
authors.forename: Michela
authors.initials: M
authors.lastname: Petrizzo
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Della Volpe
authors.forename: Rosanna
authors.initials: R
authors.lastname: Orlando
authors.forename: Dario
authors.initials: D
authors.lastname: Giugliano
authors.forename: Katherine
authors.initials: K
authors.lastname: Esposito
mesh_terms: D000071916:AC133 Antigen; D000328:Adult; D015703:Antigens, CD; D018952:Antigens, CD34; D015415:Biomarkers / Q000097:blood*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000453:epidemiology; D066026:Endothelial Progenitor Cells; D007172:Erectile Dysfunction / Q000097:blood* / Q000453:epidemiology / Q000503:physiopathology*; D005434:Flow Cytometry; D006023:Glycoproteins; D006801:Humans; D008297:Male; D010455:Peptides; D012307:Risk Factors; D013739:Testosterone / Q000097:blood*; D040301:Vascular Endothelial Growth Factor Receptor-2; D055815:Young Adult
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; D015415:Biomarkers; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; D013739:Testosterone; D040301:Vascular Endothelial Growth Factor Receptor-2