Endothelium and angiogenesis in white coat hypertension

Abstract

Hypertensive patients are at particular risk of cardiovascular complications, possibly related to endothelial damage or dysfunction, or to abnormal angiogenesis. The aim of this study was to compare the risk conferred by white coat hypertension (WCH) vs sustained hypertension in the development of the endothelial dysfunction and abnormal angiogenesis by evaluating nitric oxide (NO=NO2+/-NO3), endothelin-1 (ET-1), vascular endothelial growth factor (VEGF), and E-selectin levels in plasma. The study group included 102 subjects, 34 with WCH (17 male and 17 female patients) aged 49711 years, 34 sustained hypertensives (HT) (15 male and 19 female patients) aged 47+/-11 years and 34 normotensive control subjects (NT) (16 male and 18 female patients) aged 48+/-10 years. WCH was defined as clinical hypertension and daytime ambulatory blood pressure less than 135/85 mmHg. The subjects were matched for age, gender, body mass index and the patients with smoking habit, dyslipidaemia, and diabetes mellitus were excluded from the study. The NO, ET-1, VEGF and E-selectin levels were analysed by ELISA technique. The WCH subjects had significantly higher levels of NO than the HT ( 41.68+/-2.23 vs 32.18+/-2.68 mumol/l; P<0.001) and significantly lower values than the NT (48.24 +/- 4.29 mu mol/l; P<0.001). ET-1 levels of the WCH group were significantly higher than the NT (8.10+/-0.92 vs 5.95+/-0.26 ng/ml; P<0.001) and significantly lower than the HT (11.46 +/- 0.59 ng/ml; P<0.001). Considering with VEGF, the WCH group had significantly higher levels than the NT (195.88+/-11.84 vs 146.26+/-18.67 pg/ml; P<0.001), but the difference from the HT group was not significant (203.35 +/- 7.48 pg/ml; P=0.062). E-selectin in the WCH group was significantly lower than the HT (4.77 +/- 0.52 vs 8.49 +/- 2.85; P<0.001), but the difference from the NT group was not significant (3.86+/-0.67; P=0.077). Our data demonstrate that WCH is associated with endothelial dysfunction and abnormal angiogenesis. The degree of these changes is not as severe as observed in hypertensive population.