@article{d8bfbec023b14080b2a8208cee58b17a,
title = "Is blood pressure during the night more predictive of cardiovascular outcome than during the day?",
abstract = "The objective of this study was to investigate the prognostic significance of the ambulatory blood pressure (BP) during night and day and of the night-to-day BP ratio (NDR). We studied 7458 participants (mean age 56.8 years; 45.8% women) enrolled in the International Database on Ambulatory BP in relation to Cardiovascular Outcome. Using Cox models, we calculated hazard ratios (HR) adjusted for cohort and cardiovascular risk factors. Over 9.6 years (median), 983 deaths and 943 cardiovascular events occurred. Nighttime BP predicted mortality outcomes (HR, 1.18-1.24; P<0.01) independent of daytime BP. Conversely, daytime systolic (HR, 0.84; P<0.01) and diastolic BP (HR, 0.88; P<0.05) predicted only noncardiovascular mortality after adjustment for nighttime BP. Both daytime BP and nighttime BP consistently predicted all cardiovascular events (HR, 1.11-1.33; P<0.05) and stroke (HR, 1.21-1.47; P<0.01). Daytime BP lost its prognostic significance for cardiovascular events in patients on antihypertensive treatment. Adjusted for the 24-h BP, NDR predicted mortality (P<0.05), but not fatal combined with nonfatal events. Participants with systolic NDR of at least 1 compared with participants with normal NDR (> or = 0.80 to <0.90) were older, at higher risk of death, but died at higher age. The predictive accuracy of the daytime and nighttime BP and the NDR depended on the disease outcome under study. The increased mortality in patients with higher NDR probably indicates reverse causality. Our findings support recording the ambulatory BP during the whole day.",
keywords = "Adult, Aged, Blood Pressure, Blood Pressure Monitoring, Ambulatory, Cardiovascular Diseases, Circadian Rhythm, Cohort Studies, Databases, Factual, Female, Humans, Hypertension, Male, Middle Aged, Predictive Value of Tests, Proportional Hazards Models, Risk Factors, Survival Analysis",
author = "Yan Li and Jos{\'e} Boggia and Lutgarde Thijs and Hansen, {Tine W} and Masahiro Kikuya and Kristina Bj{\"o}rklund-Bodeg{\aa}rd and Tom Richart and Takayoshi Ohkubo and Tatiana Kuznetsova and Christian Torp-Pedersen and Lars Lind and Hans Ibsen and Yutaka Imai and Jiguang Wang and Edgardo Sandoya and Eoin O'brien and Staessen, {Jan A}",
year = "2008",
doi = "10.1097/MBP.0b013e3282fd16cc",
language = "English",
volume = "13",
pages = "145--7",
journal = "Blood Pressure Monitoring",
issn = "1359-5237",
publisher = "Lippincott Williams and Wilkins",
number = "3",
}