Abstract 4877: Circadian Variation of Blood Pressure is Correlated to Vascular Endothelial Function in Nondiabetic Essential Hypertensives
Background: Abnormal endothelium-dependent vascular relaxation in patients with essential hypertension has been described. We assessed the hypothesis that there was relationship between the circadian rhythm of blood pressure and endothelial function in patients with essential hypertension.
Methods: Non-diabetic patients with either treated or untreated essential hypertension were evaluated if their office systolic blood pressure (SBP) ≥140 mmHg or diastolic blood pressure (DBP) ≥90 mmHg. Serial studies including 24-hour ambulatory blood pressure monitoring, serum biomarkers, and brachial artery ultrasound were arranged.
Results: Thirty-nine patients were enrolled into the study. They were subclassified by their nocturnal DBP fall (25 dippers, with nocturnal DBP fall ≥10%; and 14 non-dippers, with nocturnal DBP fall <10%). The baseline characteristics and serum biomarkers including adiponectin, asymmetric dimethylargine, oxidized low-density lipoprotein, monocyte chemoattractant protein-1, high-sensitivity C-reactive protein, insulin, and nitrate and nitrite were similar between the 2 groups. The flow-mediated dilation (FMD) of brachial artery was greater in the dippers than in the non-dippers (6.1±3.1% vs. 4.1±2.6%, p=0.04) while the nitroglycerin-mediated dilation of brachial artery was similar between the two groups (14.3±5.5% vs. 13.7±6.0%, p=0.746). In all patients, sleep DBP (r=−0.379, p=0.017), nocturnal change of SBP (r=0.344, p=0.032) and DBP (r=0.420, p=0.008), and the use of calcium channel blockers (r=−0.394, p=0.013) were correlated to FMD. In multivariate analysis, only nocturnal change of DBP was the independent predictor for FMD (β=0.175, p=0.008).
Conclusions: In non-diabetic hypertensive patients, the dippers had better endothelial function than the non-dippers. Nocturnal change of DBP was the major predictor for endothelial function.