Comparison of nocturnal blood pressure dipping status detected by home vs. ambulatory blood pressure monitoring: analysis of J-HOP Nocturnal BP Study data.

Nocturnal blood pressure (BP) dipping is a risk factor for cardiovascular disease, independent of nighttime BP levels. We compared nocturnal BP dipping detected by conventional ambulatory BP monitoring (ABPM) with that detected by nocturnal home BP monitoring (HBPM), which can measure BP during sleep with a timer function. We analyzed data of 927 subjects in the nationwide practice-based J-HOP Nocturnal BP Study and observed that the prevalences of nocturnal BP dipping status for HBPM and ABPM respectively were: extreme dipper, 6.9% and 14.8%; dipper, 36.1% and 42.4%; non-dipper, 42.8% and 33.2%; riser pattern, 14.1%, and 9.6%. The agreement between nocturnal dipping classification by HBPM and ABPM was 41.0%, and when we used ≥3 days of HBPM data, the agreement rate increased to 42.8%. Obtaining an increased number of nighttime BP measurements at home for multiple days may increase the reliability of assessments of nocturnal BP dipping status detected by HBPM.