1C.05

Objective: The extent of blood pressure (BP) surge upon waking has been associated with increased cardiovascular (CVD) risk in some, but not all, studies. Numerous studies, however, have consistently shown the association between elevated sleep-time BP mean and the rising BP pattern with increased CVD risk, leading to a paradox, as patients with sleep-time hypertension or non-dipper/riser BP pattern have attenuated morning BP surge. We evaluated the comparative prognostic value for CVD events of the morning BP surge and sleep-time BP among the participants in the ongoing Hygia Project. Design and method: This study involved 11255 subjects, 6028 men/5227 women, 58.9 ± 14.5 years of age, prospectively evaluated throughout a 4.0-year median follow-up. BP was measured at 20-min intervals from 07:00 to 23:00 h and at 30-min intervals at night for 48 h. During monitoring, subjects maintained a diary listing the times of going to bed and awakening. Results: We documented 1539 total events, including 400 deaths, 176 strokes, 144 myocardial infarctions, 147 coronary revascularizations, and 193 heart failures. A greater prewaking systolic BP surge was associated with significantly lower, not higher, CVD risk in a Cox proportional-hazard model adjusted for the significant influential characteristics of age, sex, diabetes, chronic kidney disease, cigarette smoking, waist perimeter, and history of previous CVD event (hazard ratio [HR] 0.83 [95%CI 0.78–0.88] per each 1-SD increment; P < 0.001). The HR was progressively and significantly higher in the first three than in the last two quintiles of increasing prewaking BP surge. The prognostic value of morning surge markedly decreased after correcting by the asleep BP mean, the single most significant prognostic marked of total CVD events (HR = 1.37 [1.29–1.44], P < 0.001). Conclusions: Our findings document that, when properly analyzed as a continuous variable, a larger morning BP surge is associated with a significantly lower CVD risk, in line with the markedly greater risk associated with decreasing dipping of the BP pattern, and the most highly significant prognostic value of progressively elevated asleep BP, an independent prognostic marker of CVD risk that has also been prospectively validated as a relevant therapeutic target for CVD risk reduction.