Sleep deprivation deteriorates heart rate variability and photoplethysmography

Introduction: Sleep deprivation has deleterious effects on cardiovascular health. Using wearable health trackers, non-invasive physiological signals such as heart rate variability (HRV), photoplethysmography (PPG) and baroreflex sensitivity (BRS) can be analysed for detection of the effects of partial sleep deprivation on cardiovascular responses.

Methods: 15 participants underwent one week of baseline recording (BSL, usual day activity and sleep) followed by three days with three hours of sleep per night (SDP), followed by one week of recovery with sleep ad lib (RCV). HRV was recorded using an orthostatic test every morning (RMSSD, power in the low-frequency (LF) and high-frequency (HF) bands and normalized power nLF and nHF were computed), PPG and polysomnography (PSG) were recorded overnight. Continuous blood pressure and psychomotor vigilance task were also recorded. Questionnaire of subjective fatigue, sleepiness and mood states were filled regularly.

Results: RMSSD and HF decreased whilst nLF increased during SDP, indicating a decrease in parasympathetic activity and a potential increase in sympathetic activity. PPG parameters indicated a decrease in amplitude and duration of the waveforms of the systolic and diastolic periods, which is compatible with increases in sympathetic activity and vascular tone. PSG showed a rebound of sleep duration, efficiency, and deep sleep in RCV compared to BSL. BRS remained unchanged whilst vigilance decreased during SDP. Questionnaires showed an increased subjective fatigue and sleepiness during SDP.

Conclusion: HRV and PPG are two markers easily measured with wearable devices and modified by partial sleep deprivation, contradictory to BRS. Both markers showed a decrease in parasympathetic activity, known as detrimental to the cardiovascular health.