Association with obstructive sleep apnea severity and heart rate variability

초록

An unbalanced autonomic function induced by intermittent hypoxia and sleep fragmentation in obstructive sleep apnea (OSA) could be one potential reason for their increased cardiovascular risk, but mechanisms underlying the OSA-associated cardiovascular risk remain unclear. Heart rate variability (HRV) is a validated and noninvasive measurement of the influence of autonomic function on the heart and by itself associated with cardiovascular risk factors and mortality. Therefore, the aim of this study is to examine the association between HRV and OSA severity in the general population. A total of 2908 participants of the Korean Genome and Epidemiology Study, who underwent in-home polysomnography (2011-2014) were cross-sectionally analyzed. The calculation of HRV parameters was executed using echocardiographic data from polysomnography. Participants were divided into three groups based on the apnea-hypopnea index (AHI): no OSA (AHI <5, n=1535), mild OSA (5≤AHI <15, n=942) and moderate-to-severe OSA (15≤AHI, n=431). Among the groups of OSA severity, average RR interval, total power, power of the very-low-frequency band (VLF), power of the high-frequency band (HF), and ratio of low-frequency to HF power (LF/HF) showed significant differences. Compared with no OSA and mild OSA groups, the moderate-to-severe OSA group showed significantly lower average RR interval (p=0.005) and HF power (p=0.03), and higher total power (p=0.02), VLF power (p=0.006) and LF/HF (p=0.03) after adjusted age, sex, and body mass index. The severity of OSA could be attributed to imbalance of autonomic function on the heart and HRV parameters would be an effective predictor for detecting OSA-related cardiovascular comorbidities.