Associations Among Multidimensional Sleep Characteristics and Blood Pressure Reactivity to the Cold Pressor Test

Introduction Sleep is increasingly recognized as a critical behavioral determinant of cardiovascular health and is multidimensional in nature. A recent large cohort study indicated that sleep duration is not associated with resting blood pressure (BP) in healthy young adults, but the relationship between other sleep dimensions and acute BP responses to stress remains poorly understood. Therefore, the purpose of the present study was to examine the associations between multiple sleep features — specifically duration, efficiency, variability, and timing — and BP reactivity to a standardized cold pressor test (CPT) in young adults. By leveraging beat-to-beat BP monitoring and validated actigraphy-based sleep assessments, our investigation aimed to advance our understanding of the interplay between sleep and cardiovascular stress regulation. We hypothesized that sleep duration, efficiency, and timing would be negatively related, whereas sleep variability would be positively associated with the BP response to the CPT. Methods Sixty apparently healthy young adults (44F/16M; age = 25±6 y) completed one week of sleep monitoring using wrist actigraphy and concurrent daily completion of the consensus sleep diary for validation. The morning following the final night of habitual sleep assessment, participants underwent beat-by-beat blood pressure monitoring during 10 minutes of quiet rest and during 2 minutes of a CPT. Systolic, diastolic, and mean BP were averaged across the middle 8-minute epoch of the rest period and during the final minute of the CPT. The CPT response was calculated by subtracting resting BP from the BP during CPT and expressing the difference as a percentage of resting BP. To capture the multidimensional nature of sleep, sleep duration, sleep efficiency, night-to-night sleep duration variability, and sleep midpoint (timing) were assessed and averaged across the monitoring period. The BP response to the CPT was analyzed using paired t-tests, and partial Pearson correlation coefficients (adjusted for age and sex) were used to examine associations between sleep parameters and BP measurements at rest and in response to CPT. Results The CPT induced significant increases in systolic (+12±2 mmHg; p < 0.001), diastolic (+9±1 mmHg; p < 0.001), and mean (+10±1 mmHg; p < 0.001) BP. No sleep parameters were associated with systolic, diastolic, or mean BP at rest (all p > 0.30). Neither sleep duration nor the midpoint of sleep was associated with the systolic, diastolic, or mean BP response to the CPT (all p ≥ 0.24). However, sleep efficiency was significantly associated with systolic (r XY·Z = 0.35, p = 0.02), diastolic (r XY·Z = 0.27, p = 0.08), and mean (r XY·Z = 0.31, p = 0.04) BP in response to the CPT, and night-to-night sleep duration variability was inversely associated with systolic (r XY·Z = -0.40, p = 0.01), diastolic (r XY·Z = -0.34, p = 0.03), and mean (r XY·Z = -0.37, p = 0.02) BP in response to the CPT. Conclusion Our findings indicate that sleep duration, efficiency, timing, and variability are not associated with resting blood pressure. However, sleep efficiency was associated with greater BP reactivity, while sleep variability was associated with lower BP reactivity to the CPT. These findings were directionally opposite of our hypothesis yet still suggest that sleep quality and variability may be linked with altered blood pressure regulation. These findings also highlight the need to consider the multidimensional nature of sleep to fully understand its effects on cardiovascular health. Funding provided by a grant from the Injury Prevention Research Center through the CDC (R49 CE003095; NDMJ) This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.