Sleep blood pressure measured using a home blood pressure monitor was independently associated with cardiovascular disease incidence: the Nagahama study.

BACKGROUND

Nocturnal blood pressure (BP) is associated with cardiovascular disease independently of awake BP. However, nocturnal BP measured using an ambulatory monitoring device has limited reproducibility because it is a single-day measurement. We investigated the association between sleep BP measured on multiple days using a timer-equipped home BP monitor and cardiovascular diseases in a general population.

METHODS

The study population comprised 5814 community residents. Participants were required to sleep with wrapping cuffs on their upper arm and 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 and evening BP manually using the same device.

RESULTS

During the 7.3-year mean follow-up period, we observed 117 cases of cardiovascular diseases. The association between sleep BP (per 10 mmHg hazard ratio = 1.31, P  < 0.001) and cardiovascular events remained significant (hazard ratio = 1.22, P  = 0.036) even after adjusting for office BP and confounding factors, such as sleep-disordered breathing. Individuals with sleep-only hypertension ( n  = 1047; hazard ratio = 2.23, P  = 0.005) had a significant cardiovascular risk. Daytime-only hypertension ( n  = 264; hazard ratio = 3.57, P  = 0.001) and combined sleep and daytime hypertension ( n  = 1216; hazard ratio = 3.69, P  < 0.001) was associated with cardiovascular events to the same extent. Sleep BP dipping was not identified as a significant determinant of cardiovascular events.

CONCLUSION

Sleep BP measured using a home BP monitor was independently associated with the incidence of cardiovascular disease in a general population.