0483 Real-world Study of Heart Rate Variability During Sleep Using Under-mattress Sensors in over 30,000 Individuals

Abstract Introduction Heart rate variability (HRV), the beat-to-beat variation of the heartbeat signal, is a quantitative marker of Autonomic Nervous System (ANS) balance that may be influenced by obstructive sleep apnea (OSA) if measured during sleep. Notably, little is known about overnight HRV, and how this metric may differ by age, gender, or severity of OSA. Methods We used a commercially available home monitoring device (Sleeptracker-AI Monitor, Fullpower Technologies Inc., California, USA) that measures HRV non-invasively and continuously during sleep using under-mattress piezo-electric sensors. We focus on two key HRV time domain metrics, the root mean square of successive RR interval differences (RMSSD, a measure used to estimate parasympathetic activity) and standard deviation of RR intervals between normal heartbeats (SDNN, a measure of overall variability influenced by both sympathetic and parasympathetic activity). Results We included data from 38,475 subjects 20712 males, 46.9±12.7 years; 17763 females, 46.7±12.6 years; 1575 with moderate to severe OSA (AHI≥15) and 30,816 without OSA (AHI 5) with 2,720,720 recorded nights, collected from 08/16/2023 to 12/15/2023. Both HRV metrics decreased with age, whereas SDNN was lower in females. For both females and males, individuals with moderate to severe OSA had significantly lower RMSSD than those without OSA, though these differences decreased with age and were only significant among those aged 20-39 years mean difference (MD)=-5.21, standard error (SE)=1.66 for females; -6.57, 0.97 for males or 40-59 years MD=-2.33, SE=0.60 for females; -2.43, 0.33 for males. Meanwhile, individuals with moderate to severe OSA had significantly higher SDNN than those with no OSA, and these differences increased with age and were only significant among those aged 40-59 years MD=2.39, SE=0.82 for females; 2.33, 0.42 for males or 60-79 years MD=2.14, SE=0.89 for females; 1.91, 0.56 for males. For all age groups, men with moderate to severe OSA had significantly higher heart rate (HR) compared to those without OSA. Conclusion HRV during sleep varies with age, gender, and severity of OSA. OSA severity had different associations with HRV metrics relevant to sympathetic vs. parasympathetic activity. Emerging sleep technologies provide new opportunities for clarifying the association between HRV during sleep and OSA. Support (if any) Support from Fullpower Technologies.