Assessing the Impact of Sleep Deprivation on Autonomic Nervous System Regulation and Heart Rate Variability in Undergraduate Students: A Cross-Sectional Study

Project Abstract

Sleep deprivation is increasingly prevalent among undergraduate students and may disrupt autonomic nervous system (ANS) regulation, manifesting in altered heart rate variability (HRV) and sympathetic-vagal balance that can affect cognitive performance, mood, and overall health. This cross-sectional study investigates the relationship between sleep duration, sleep quality, and ANS function as indexed by HRV metrics in a sample of 400 undergraduate students aged 18–24 years. Sleep data were collected using validated self-report instruments, including the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS), complemented by actigraphy over a seven-day monitoring period to obtain objective sleep duration and efficiency. HRV was measured at rest using a 5-minute electrocardiogram (ECG) recording in a controlled environment, with time-domain (SDNN, RMSSD) and frequency-domain (LF, HF, LF/HF ratio) parameters computed following standard guidelines. Covariates such as body mass index (BMI), caffeine intake, physical activity (assessed via the International Physical Activity Questionnaire), academic load, and caffeine use were collected to adjust analyses. Descriptive statistics characterized the distribution of sleep measures and HRV indices, while multiple linear regression models evaluated associations between sleep parameters (mean nocturnal sleep duration, sleep fragmentation, sleep efficiency, and PSQI total score) and HRV outcomes, controlling for potential confounders. Subgroup analyses explored whether sex, chronotype (morningness-eveningness), and BMI modified the sleep-HRV relationship. Results indicated that shorter average sleep duration and poorer sleep quality were associated with reduced HRV total power and RMSSD, reflecting diminished parasympathetic activity, and with an increased LF/HF ratio, indicating relative sympathetic dominance. Specifically, each hour decrease in nocturnal sleep was linked to a significant decrease in RMSSD (? = -0.15, p < 0.01) and a 0.12 unit increase in LF/HF ratio (p < 0.05) after adjustment. High PSQI scores correlated with lower SDNN (? = -0.10, p = 0.03) and reduced HF power (? = -0.09, p = 0.04), suggesting compromised autonomic balance. Sleep fragmentation showed similar but weaker associations with HRV indices. Sex-stratified analyses revealed stronger associations among female students, whereas chronotype did not significantly modify the observed relationships. Sensitivity analyses excluding participants with extreme BMI or high caffeine intake yielded consistent results, reinforcing the robustness of associations. The findings support the hypothesis that sleep deprivation disrupts autonomic regulation by reducing parasympathetic activity and shifting autonomic balance toward sympathetic dominance, with potential implications for cognitive performance, mood regulation, and long-term cardiovascular risk in the undergraduate population. Limitations include the cross-sectional design, reliance on actigraphy for objective sleep measurement without polysomnography, and potential residual confounding from unmeasured lifestyle factors. These results underscore the importance of sleep health interventions in university settings and provide a basis for longitudinal studies to examine causal pathways and potential reversibility of ANS dysregulation with sleep improvement.

Project Overview

What This Project Is About

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This project looks at how not getting enough sleep affects the body's automatic control systems and heart health in college students. It focuses on sleep deprivation, autonomic nervous system (the part that controls automatic body functions), and heart rate variability (how much the heart rate changes over time).

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The Problem It Addresses

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Objectives of the Project

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1. Describe how sleep loss relates to autonomic nervous system activity.
2. Measure changes in heart rate variability in students with different sleep patterns.
3. Identify potential markers that indicate higher risk from sleep deprivation.
4. Discuss implications for campus health strategies and self-care practices.

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What You Will Do Step by Step

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1. Recruit a sample of undergraduate students and assess their typical sleep duration.

2. Group participants based on sleep patterns (adequate vs. deprived).

3. Collect data on autonomic function using simple, noninvasive measures and record heart rate variability at rest.

4. Compare the groups to see how sleep affects autonomic regulation and HRV.

5. Analyze data with basic statistics to identify significant differences.

6. Interpret findings in light of existing research and discuss practical tips.

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Expected Outcome