Sleep and cardiovascular outcomes in relation to nocturnal hypertension: the J-HOP Nocturnal Blood Pressure Study

There is a lack of data on how nighttime blood pressure (BP) might modify the relationship between sleep duration and cardiovascular disease (CVD) risk. Self-reported sleep duration data were available for 2253/2562 patients from the J-HOP Nocturnal BP study; of these, 2236 had complete follow-up data (mean age 63.0 years, 83% using antihypertensive drugs). CVD outcomes included stroke, coronary artery disease (CAD), and atherosclerotic CVD (ASCVD [stroke + CAD]). Associations between sleep duration and nighttime home BP (measured using a validated, automatic, oscillometric device) were determined. During a mean follow-up of 7.1 ± 3.8 years, there were 133 ASCVD events (52 strokes and 81 CAD events). Short sleep duration (<6 versus ≥6 and <9 h/night) was significantly associated with the risk of ASCVD (hazard ratio [HR] 1.85, 95% confidence interval [CI] 1.07–3.22), especially stroke (HR 2.47, 95% CI 1.08–5.63). When nighttime systolic BP was <120 mmHg, those with a sleep duration <6 versus ≥6 and <9 h/night had a significantly higher risk of ASCVD and CAD events (HR [95% CI] 3.46 [1.52–7.92] and 3.24 [1.21–8.69], respectively). Even patients with “optimal” sleep duration (≥6 and <9 h/night) were at significantly higher risk of stroke when nighttime systolic BP was uncontrolled (HR [95% CI] 2.76 [1.26–6.04]). Adding sleep duration and nighttime BP to a base model with standard CVD risk factors significantly improved model performance for stroke (C-statistic 0.795, 95% CI 0.737–0.856; p = 0.038). These findings highlight the importance of both optimal sleep duration and control of nocturnal hypertension for reducing the risk of CVD, especially stroke. Clinical Trial registration: URL: http://www.umin.ac.jp/icdr/index.html . Unique identifier: UMIN000000894.