The Number of Endothelial Progenitor Cells is Decreased in Patients With Non-Dipper Hypertension.
OBJECTIVE
Circulating endothelial progenitor cells (EPCs) play a key role in the maintenance of endothelial homeostasis and promote vascular repair. A reduced number of EPCs and the functional activity have been associated with several cardiovascular risk factors. However, the relationship between the number of EPCs and circadian rhythm of the blood pressure (BP) remains unclear. The purpose of the present study was to evaluate the relationship between the circadian rhythm of the BP and EPCs in patients with essential hypertension.


METHODS
A total of 45 patients with essential hypertension who were newly identified by outpatient BP measurements, underwent 24-hour ambulatory BP monitoring. Among the 45 patients with essential hypertension, 20 were classified as dippers (12 men and 8 women; mean age 48±14 years) and 25 as non-dippers (14 men and 11 women; mean age 52±18 years). The EPC count was isolated from the peripheral bloodstream and quantified by flow cytometry.


RESULTS
The baseline clinical characteristics were similar between the dipper and non-dipper hypertensive patients. The circulating EPCs were statistically reduced in the non-dipper patients as compared to the dippers (104±60 vs. 66±47 EPCs per 106 mononuclear cells, p=0.027). The circulating EPC level correlated positively with the circadian changes in the systolic and diastolic BP (r=0.435, p=0.003, and r=0.310, p=0.038, respectively).


CONCLUSIONS
The present study demonstrated that the EPC count was reduced in the peripheral bloodstream in non-dipper hypertensive patients.
Department of Cardiovascular Center, Regional Cardiocerebrovascular Disease Center, Wonkwang University Hospital, Iksan, Korea.
Seunghwan
S
Kim
Nam-Ho
NH
Kim
Yong Kwon
YK
Kim
Jong Hyun
JH
Yoo
Seong Nam
SN
Shin
Jum Suk
JS
Ko
Yun Kyeong
YK
Kim
Sang Jae
SJ
Rhee
Kyeong Ho
KH
Yun
Eun Mi
EM
Lee
Nam Jin
NJ
Yoo
Seok Kyu
SK
Oh
Jin-Won
JW
Jeong