0964 A Multidimensional Assessment of Actigraphy-Measured Sleep and 24-Hour Ambulatory Blood Pressure Outcomes in the Multi-Ethnic Study of Atherosclerosis

Introduction Few population-based, longitudinal studies have examined the relationship between multidimensional sleep health and ambulatory blood pressure monitoring (ABPM) outcomes, which improves measurement accuracy in naturalistic settings of inadequate sleep. Methods We analyzed data from 593 Multi-Ethnic Study of Atherosclerosis participants. At Exam 5 (2010-2013), participants wore an actigraph for 7 days, from which we estimated multidimensional sleep health metrics, including duration, regularity, timing, and fragmentation. At Exam 7 (2021-2024), participants underwent 24-hour ABPM. We assessed average nocturnal systolic (SBP) and diastolic blood pressure (DBP). We defined nocturnal hypertension as average nocturnal blood pressure ≥120/70 mmHg and non-dipping nocturnal SBP and DBP as < 10% average decrease from wake-to-sleep. We used linear and log-Poisson regression, adjusted for Exam 5 socio-demographics, body mass index, cigarette smoking, alcohol intake, physical activity, and anti-hypertensive usage, to estimate mean differences (MDs) and prevalence ratios (PRs) and 95% confidence intervals (CIs). Results At Exam 7, mean nocturnal SBP/DBP were 118/64 mmHg. Prevalence of nocturnal hypertension and non-dipping SBP and DBP was 46.2%, 49.8%, and 38.8%, respectively. Compared to participants in the highest quartile of total sleep time (TST; ≥7.3 hours), participants in the lowest quartile (≤5.9 hours) had higher prevalence of nocturnal hypertension (PR=1.25, 95% CI=0.94-1.65) and non-dipping SBP (1.27 [0.97-1.64]) and DBP (1.21 [0.88-1.66]). These participants also had higher nocturnal SBP (MD=2.93, 95% CI=-0.97-6.83 mmHg) and DBP (1.46 [-0.66-3.57] mmHg). Participants in the highest quartile of irregularity had higher prevalence of nocturnal hypertension (TST variability: 1.27 [1.00-1.61]; sleep maintenance efficiency [SME] variability: 1.38 [1.06-1.80]), non-dipping nocturnal SBP (SME variability: 1.23 [0.96-1.57]), and DBP (midpoint variability: 1.24 [0.92-1.67]; TST variability: 1.30 [1.00-1.69]); continuous outcomes showed similar patterns. Compared to the lowest quartile of Sleep Fragmentation Index, participants in the highest quartile had higher prevalence of nocturnal hypertension (1.14 [0.89-1.46]) and non-dipping nocturnal SBP (1.40 [1.10-1.77]) and DBP (1.21 [0.92-1.60]). We observed similar, yet imprecise, results for nocturnal SBP (1.92 [-1.92-5.77] mmHg) and DBP (1.16 [-0.92-3.25] mmHg). Conclusion Actigraphy-measured short sleep duration, irregularity, and fragmentation were associated with nocturnal blood pressure outcomes, reinforcing the importance of ABPM and need for multidimensional composite sleep assessments. Support (if any)