Association between sleep disturbance and nocturnal blood pressure profiles by a linear mixed model analysis: the Nagahama study

Abstract

ObjectivesWe aimed to analyze associations of sleep disturbance, including sleep disordered breathing, sleep fragmentation, and sleep efficiency, with abnormal nocturnal blood pressure (BP) profiles that may be risk factors for adverse cardiovascular outcomes. MethodsThe study included 5854 community residents with 20,725 multi-day measurements. Sleep fragmentation and efficiency were evaluated using a wrist-worn activity monitor. Sleep disordered breathing was assessed using the 3% oxygen desaturation index corrected for actigraphy-determined sleep duration. A timer-equipped standard cuff-oscillometric device was used for home and sleep BP monitoring. ResultsMean nocturnal systolic BP (SBP) change was −8.6 ± 9.7% (−11.1 ± 12.6 mmHg), and inter-day correlation coefficient of the nocturnal SBP change was 0.443. Results of a linear mixed model analysis using daily measured values identified lower sleep efficiency (coefficient = −0.130, p < 0.001) as a determinant for decreased nocturnal SBP dipping beyond the interday variations of these parameters. Number of nocturnal urinations was another strong determinant (coefficient = 1.191, p < 0.001), although the association of sleep efficiency was independent of nocturnal urination, awake SBP, and sleep disordered breathing (coefficient = −0.102, p < 0.001). Sleep efficiency was also independently associated with sleep SBP level (coefficient = −0.138, p < 0.001). Estimated differences in nocturnal SBP dipping and sleep SBP level as a function of the degree of sleep efficiency (less than 80%) reached 1.63% (1.09–2.17%) and 2.16 mmHg (1.49–2.82%), respectively. ConclusionMore attention should be paid to sleep efficiency as a factor in maintaining circadian BP rhythm.