Abstract 15526: Nocturnal Hypertension as a Novel Early Indicator of Vascular Injury and Cardiac Hypertrophy in Untreated Hypertension
Background: Controversial remains the correlation of nocturnal hypertension (NH) with subclinical target organ damage. The purpose of this study was to compare nocturnal hypertensive with normotensive subjects regarding preclinical vascular damage, cardiac hypertrophy and renal function, as indices of subclinical target organ damage in hypertension.
Methods: The study population consisted of 302 untreated essential hypertensives. Individuals with ≥10% difference in nocturnal systolic blood pressure in comparison to daytime values were defined as dippers, whereas non-dippers were defined as those with <10% nocturnal decrease. In all participants, carotid-femoral pulse wave velocity (cf-PWV), flow mediated dilation (FMD), intima-media thickness of carotid arteries (C-IMT), augmentation index, ankle-brachial index. Also, left ventricular mass index (LVMI) and E/A (the mean ratio of early and late diastolic tissue velocities) were assessed by echocardiography. Serum cystatin-C levels were measured by ELISA kit. We also assessed GFR by the Cockcroft-Gault formula.
Results: Based on the presence of NH (>120/70 mmHg), the population was divided into two groups: nocturnal normotensive (n=150) and nocturnal hypertensive subjects (n=152), who did not differ in classical risk factors. Patients with NH were characterized by increased arterial cf-PWV (91±1.7 vs 8.4±1.5 m/sec, p=0.0001) and marginally decreased FMD values (5.1±3.4 vs 4.1±2.6, p=0.066). In addition, this group showed increased C-IMT (0.77±0.18 vs 0,69±0,15 mm, p=0.016) compared to normotensive subjects, whereas no other significant differences were observed, regarding other vascular indices (p=NS for both). Notably, they also exhibited impaired values of LVMI (88.1±22.9 vs 82.8±16.6 gr/m2, p=0.043) and E/A (0.90±0.26 vs 0.88±0.43, p=0.030), respectively. However, the two groups did not differ with respect to renal function, based on the values both of GFR (p=0.689) and cystatin-C (p=0.283).
Conclusions: According to this study, the presence of nocturnal hypertension is accompanied by subclinical atherosclerosis, as well as structural and functional abnormalities of the left ventricle, without significant association with renal function in untreated hypertensive.
- © 2013 by American Heart Association, Inc.