A8629 Isolated Nocturnal Hypertension and Its Association with Subclinical Target Organ Damage in Untreated Chinese Patients

Abstract

Objectives: Isolated nocturnal hypertension (HT) was termed as a condition of an elevated nighttime blood pressure in the presence of a daytime normotension. The clinical relevance of isolated nocturnal HT has not been comprehensively clarified regarding subclinical target organ damage. Methods: Consecutive untreated patients referred for ambulatory blood pressure (BP) monitoring to our Hypertension Clinic were recruited. The cutoff values for daytime and nocturnal hypertension were a BP of ≥135/85 mmHg and ≥120/70 mmHg, respectively. We measured subclinical target organ damage, including left ventricular mass index (LVMI), E/e’ ratio by echocardiography, carotid-femoral pulse wave velocity (cfPWV), urinary albumin-to-creatinine ratio (ACR) and brachial artery flow-mediated dilation (FMD). Results: The 1808 participants (mean age, 51 years; women, 52%) included 428 (23.7%) ambulatory normotensives, 252 (13.9%) with isolated daytime HT, 209 (11.6%) isolated nocturnal HT and 919 (50.8%) day-night HT. Patients with isolated nocturnal HT were younger (53.4 versus 55.0 years), more often reported as male (42.8% vs 30.2%), drinker (15.4% versus 10.5%) and smoker (15.4% versus 6.5%) compared with ambulatory normotensives. Compared with patients with ambulatory normotension, patients with isolated nocturnal HT had higher cfPWV (7.7 vs 7.5 m/s, P = 0.024), urinary ACR (0.71 vs 0.58 mg/mmol, P = 0.006) and higher E/e’ ratio (10.0 vs 9.6, P = 0.04) after multivariate adjustment. As for FMD and LVMI, no difference (P ≥ 0.23) between isolated nocturnal HT and ambulatory normotension was observed. Conclusion: Isolated nocturnal HT was associated with target organ damage. Ambulatory BP measurement may help clinicians to identify these patients with increased cardiovascular risk.