Abstract 34: Quantifying Pulse Arrival Time Changes Across Sleep-Disordered Breathing Events: Insights from the MESA Sleep Study

Pulse arrival time (PAT), the interval between cardiac electrical activity and peripheral pulse detection, reflects beat-to-beat vascular reactivity and autonomic tone. Sleep-related respiratory events, including apneas, hypopneas, and oxygen desaturations, may transiently alter PAT via changes in intrathoracic pressure and sympathetic activation. However, relationships between event type, sleep-apnea status, and PAT remain unclear. We hypothesized that PAT decreases during respiratory disturbances and that these changes differ across respiratory event types. We analyzed 203 participants in the MESA Sleep Study, each with respiratory events scored by technicians. Sleep-apnea status was defined by the apnea–hypopnea index (AHI). Per-patient mean PAT was compared between respiratory-event and non-event segments using the Wilcoxon signed-rank test. A mixed-effects model evaluated PAT across event types, using non-event segments as reference. Subgroup comparisons by sex, BMI, race, and sleep-apnea status used nonparametric tests. Average PAT was significantly lower during respiratory-event versus non-event segments (p<0.01). In mixed-effects modeling, PAT was reduced during SpO desaturations (−2.34 ms), hypopneas (−1.58 ms), obstructive apneas (−1.35 ms), and other uncharacterized sleep disturbance events (−2.00 ms), all p<0.001 relative to non-event segments (194.3 ms). Between-patient variance accounted for 36.5% of total variability (ICC=0.365). PAT was shorter among males (191.3 vs 196.1 ms, p=0.015) and trended lower with higher BMI (p=0.055). During non-event periods, shorter PAT persisted among males (p=0.019), those with sleep apnea (195.4 vs 188.7 ms, p=0.047), and higher BMI (p=0.047). PAT during respiratory events showed minimal group differences except for sex (p=0.017), suggesting baseline rather than event-specific variation. PAT decreases during respiratory disturbances, particularly during desaturation and obstructive events, consistent with transient autonomic and vascular responses. Sex, BMI, and sleep-apnea status modify baseline PAT but have weaker effects during respiratory events. The stronger association of sleep-apnea status with PAT during non-respiratory periods likely reflects chronic vascular remodeling and autonomic dysregulation in those with higher AHI. These findings support PAT as a physiologic biomarker of sleep-disordered-breathing severity and cardiovascular stress.

Duke Scholars

Author Jessilyn Dunn Biomedical Engineering