Association Between Habitual Sleep Duration Variability and Cardiovascular Reactivity to Mental Stress

Authors

Anjana Chepur, Baylor UniversityFollow
Jeremy A. Bigalke, Baylor UniversityFollow
Jason R. Carter, Baylor UniversityFollow

Abstract

Nightly variability in sleep duration is an independent predictor of cardiovascular risk, yet the physiological mechanisms underlying this association remain unclear. Few investigations have focused on whether variability in habitual sleep duration influences autonomic and cardiovascular responses to acute stress. PURPOSE: The purpose of this study was to examine whether habitual variability in nightly sleep duration predicts autonomic and cardiovascular reactivity to acute psychosocial stress, as measured by blood pressure, heart rate, and heart rate variability (HRV) changes during the Trier Social Stress Test (TSST). We hypothesized that individuals with greater sleep duration variability would exhibit exaggerated autonomic and cardiovascular reactivity to acute stress compared to individuals with lower sleep duration variability. METHODS: Twenty-six healthy young adults (age: 21 ± 4 year; BMI: 23 ± 3 kg/m²) participated in the present study. Each participant wore an Oura ring at-home for 7-14 days to monitor sleep. Habitual sleep duration variability was quantified as the standard deviation of sleep duration across nights. Participants were stratified into high versus low sleep variability groups using a median split. Each participant then attended an in-laboratory testing session where continuous recordings of heart rate (HR, electrocardiogram) and beat-to-beat blood pressure (BP, finger plethysmography) were monitored for a 10m baseline and throughout the TSST which consists of speech preparation (5m), speech (5m), and mental arithmetic (5m) phases. Reactivity in mean arterial pressure (MAP), HR, as well as HRV quantified as the root mean square of successive differences (RMSSD) and high-frequency (HF-HRV) component throughout the TSST relative to baseline were compared between low versus high sleep variability groups. RESULTS: Individuals in the low sleep duration variability group were slightly older (low: 23 ± 5 vs. high: 19 ± 2 years, p0.05). Across the full sample, the TSST evoked a strong stress response, demonstrated by significant time effects with increases in MAP (p

Recommended Citation

Chepur, Anjana; Bigalke, Jeremy A.; and Carter, Jason R. (2026) "Association Between Habitual Sleep Duration Variability and Cardiovascular Reactivity to Mental Stress," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 18, Article 183.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss18/183