The Effect of Aging and Severity of Sleep Apnea on Heart Rate Variability Indices in Obstructive Sleep Apnea Syndrome

Abstract

ObjectiveThis study aims to analyze how much heart rate variability (HRV) indices discriminatively respond to age and severity of sleep apnea in the obstructive sleep apnea syndrome (OSAS).Methods176 male OSAS patients were classified into four groups according to their age and apnea-hypopnea index (AHI). The HRV indices were compared via analysis of covariance (ANCOVA). In particular, the partial correlation method was performed to identify the most statistically significant HRV indices in the time and frequency domains. Stepwise multiple linear regressions were further executed to examine the effects of age, AHI, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), and sleep parameters on the significant HRV indices.ResultsThe partial correlation analysis yielded the NN50 count (defined as the number of adjacent R-wave to R-wave intervals differing by more than 50 ms) and low frequency/high frequency (LF/HF) ratio to be two most statistically significant HRV indices in both time and frequency domains. The two indices showed significant differences between the groups. The NN50 count was affected by age (p<0.001) and DBP (p=0.039), while the LF/HF ratio was affected by AHI (p<0.001), the amount of Stage 2 sleep (p=0.005), and age (p=0.021) in the order named in the regression analysis.ConclusionThe NN50 count more sensitively responded to age than to AHI, suggesting that the index is mainly associated with an age-related parasympathetic system. On the contrary, the LF/HF ratio responded to AHI more sensitively than to age, suggesting that it is mainly associated with a sympathetic tone likely reflecting the severity of sleep apnea.

Use of Mutual Information and Transfer Entropy to Assess Interaction between Parasympathetic and Sympathetic Activities of Nervous System from HRV

“…First, we did not account for age and OSA severity which also influence the function of ANS [45]. Second, the effect of different sleep stages was not taken into account.…”

“…Gula et al [9] and Park et al [17] demonstrated that patients with more severe OSA exhibited a higher LF/HF which represents the balance between the sympathetic and parasympathetic systems. The experiment by Pan et al [5] was performed on 10 mild OSA patients, 24 moderate OSA patients, 45 severe OSA patients, and 10 normal participants. They found a reduction in sample entropy (SampEn) with an increase in severity of OSA and multiscale entropy index into small scale (MEIss) of normal subjects and mild OSA patients were significantly higher than that of moderate OSA and severe OSA patients.…”

The effect of sleep apnea severity on cardiac autonomic activity during night time in obstructive sleep apnea patients

“…[19][20][21][24][25][26][27] The authors of these studies thought that this deterioration might be due to hypoxia during periods of apnea. Ari et al 19 reported that HRT worsened in OSA while HRV did not change and there was a relationship between HRT and AHI.…”

Heart rate variability - current diagnosis of the cardiac autonomic neuropathy. A review

“…61 ), patients in chronic hemodialysis 62 , systemic inflammatory diseases 63 . As a diagnostic auxiliary tool HRV can be used in testing the patients with syncope 64 , sleep apnea 65 , in psychiatry in diagnosis and during treatment of depression 66 . It is a recognized method for monitoring critical conditions in neonatology 67 .…”