Circulating CD34
+
KDR
+
Endothelial Progenitor Cells Correlate with
Erectile Function and Endothelial Function in Overweight Men
Katherine Esposito, MD, PhD,* Miryam Ciotola, MD,* Maria Ida Maiorino, MD,*
Francesco Giugliano, MD,
†
Riccardo Autorino, MD,
†
Marco De Sio, MD,
†
Emmanuele Jannini, MD,
‡
Andrea Lenzi, MD,
§
and Dario Giugliano, MD, PhD*
*Department of Geriatrics and Metabolic Diseases, Division of Metabolic Diseases, Second University of Naples,
Naples, Italy;
†
Division of Urology, Second University of Naples, Naples, Italy;
‡
School of Sexology, University of
L’Aquila, Italy;
§
Department of Medical Physiopathology, La Sapienza University, Rome, Italy
DOI: 10.1111/j.1743-6109.2008.01042.x
ABSTRACT
Introduction. Bone marrow-derived endothelial progenitor cells (EPCs) circulate in the peripheral blood and are
involved in endothelial homeostasis and repair.
Aim. The aim of this study was to assess the circulating levels of different EPC phenotypes in overweight men with
or without erectile dysfunction (ED). As endothelial dysfunction is considered a necessary link with ED,
endothelium-dependent vasodilation and its relation with EPCs were also investigated.
Methods. We studied 30, otherwise healthy, overweight subjects with symptomatic ED for at least 6 months, and 30
age- and weight-matched subjects without ED. Erectile function was assessed by completing the International Index
of Erectile Function (IIEF-5), which consists of items 5, 15, 4, 2, and 7 from the full-scale IIEF-15.
Main Outcome Measures. Seven subpopulations of EPCs were determined by flow cytometry on the basis of the
surface expression of CD34, CD133, and KDR antigens: CD34
+
, CD133
+
, KDR
+
, CD34
+
CD133
+
, CD34
+
KDR
+
,
CD133
+
KDR
+
, and CD34
+
CD133
+
KDR
+
. Endothelium-dependent flow-mediated dilation (FMD) was evaluated in
the right brachial artery with a high-resolution ultrasound machine following reactive hyperemia.
Results. CD34
+
KDR
+
cell count was significantly lower in men with ED as compared with men without ED
(63.1 4 vs. 92.4 6 cells/10
6
events, mean standard error, P < 0.01). There was a significant direct correlation
between circulating CD34
+
KDR
+
cells and the IIEF score (r = 0.44; P = 0.01): men with the severe form of ED
presented the lowest level of circulating EPC CD34
+
KDR
+
cells. No significant correlation was found between the
circulating levels of the other EPC phenotypes and the IIEF score. There was a significant correlation between
CD34
+
KDR
+
cell count and FMD (r = 0.45; P = 0.01), but not between FMD and the other phenotypes.
Conclusions. Circulating levels of CD34
+
KDR
+
EPC are reduced in overweight subjects with ED and correlate with
the severity of ED. Other EPC phenotypes are not related to ED, suggesting that the CD34
+
KDR
+
phenotype of
EPCs may be preferred in future studies. Esposito K, Ciotola M, Maiorino MI, Giugliano F, Autorino R, De Sio
M, Jannini E, Lenzi A, and Giugliano D. Circulating CD34
+
KDR
+
endothelial progenitor cells correlate with
erectile function and endothelial function in overweight men. J Sex Med 2009;6:107–114.
Key Words. Circulating Endothelial Progenitor Cells; Erectile Dysfunction; Endothelial Dysfunction; Overweight
Subjects
Introduction
E
rectile dysfunction (ED) affects 30 million
men in the United States and more than
150 million men worldwide, compromising mul-
tiple aspects of a patient’s life, including overall
quality of life and interpersonal relationships [1].
ED is associated with hypertension, diabetes mel-
litus, obesity, metabolic syndrome, hyperlipidemia,
smoking, alcohol, and sedentary behavior; endot-
helial dysfunction seems to have a key role in these
associations [2,3]. ED is often the first clinical sign
107
© 2008 International Society for Sexual Medicine J Sex Med 2009;6:107–114