Sleep Blood Pressure Measured With a Home Blood Pressure Monitor Was Independently Associated With Incidence of Cardiovascular Diseases: The Nagahama Study

Objective: Nocturnal blood pressure (BP) was reported to be associated with cardiovascular diseases. However, nocturnal BP measured using ambulatory monitoring device usually includes BP without sleep. We investigated an association between sleep BP measured using a timer-equipped home BP monitor and cardiovascular diseases in a general population. Design and method: Study population was 6,037 middle-aged and older community residents (mean age: 57.8 years old, men: 30.9%). Participants were required to sleep with wrapping cuffs in the upper-arm and sleep BP was measured automatically at 0:00, 2:00, and 4:00. Actigraph was used to determine BP measured during sleep. Participants were also measured home morning BP manually using a same device. Incidence of cardiovascular diseases including stroke and myocardial infarction were assessed by reviewing personal hospital records. Results: Mean morning systolic and diastolic BP was 126 ± 18 and 77 ± 11 mmHg, respectively, while sleep systolic and diastolic BP was 112 ± 15 and 66 ± 9 mmHg. During 5.0 years mean follow-up period, we observed 80 cases of cardiovascular diseases (stroke and myocardial infarction). Morning hypertension (>135/85 mmHg) hazard ratio (HR) = 3.22, P 120/70 mmHg) [HR = 2.21, P = 0.002, but not office hypertension (>140/90 mmHg) HR = 1.44, P = 0.127, was significantly associated with incidence of cardiovascular diseases independently of age, sex, and body mass index. Clinical characteristics including sleep efficiency (normotension: 91 ± 4%, sleep hypertension: 89 ± 5%, morning hypertension: 90 ± 4%, sleep and morning hypertension: 89 ± 5%, P< 0.001) and oxygen desaturation index (5.9 ± 4.8, 8.3 ± 6.6, 9.3 ± 7.1, 11.1 ± 9.0 times/h, P < 0.001) differed significantly by the hypertension status. However, sleep hypertension HR = 2.94, P = 0.015, morning hypertension HR = 4.81, P < 0.001, and sleep and morning hypertension HR = 4.71, P < 0.001 was identified as significant factors for cardiovascular diseases after adjustment of covariates including the sleep parameters. Conclusions: High sleep BP measured home BP monitoring device was independently associated with incidence of cardiovascular disease in a general population.