• Sleep Medicine and Psychophysiology
• /
• v.19 no.1
• /
• pp.27-34
• /
• 2012

Objectives: The analysis of heart rate variability (HRV) is a useful non-invasive tool to investigate the autonomic nerve function. Previous studies on the relationship between HRV and depression have been reported controversial results. Similarly, the correlation between the serum lipids and depression is debatable. The purpose of this study is to examine the relationship between heart rate variability, lipid profile and depression. Methods: A total of 42 patients with major depressive disorder (MDD) and 32 age and sex-matched normal subjects who had no previous history of major medical and mental illnesses were recruited for this study. A structured-interview was used to assess the general characteristics and psychiatric illness. HRV measures were assessed by time-domain and frequency-domain analyses. Psychological symptoms were measured using the Hamilton rating scale for anxiety (HAM-A), Hamilton rating scale for depression (HAM-D). In addition, the evaluation for lipid profile was performed by blood test. Results: In serum lipid profile test, MDD group showed higher cholesterol ($197.68{\pm}42.94$ mg/dL vs. $176.85{\pm}34.68$ mg/dL, p=0.044), TG ($139.45{\pm}92.54$ mg/dL vs. $91.4{\pm}65.68$ mg/dL, p=0.018), LDL ($130.03{\pm}33.18$ vs. $106.62{\pm}27.08$, p=0.004) level than normal control group. In HRV time domain analyses, the standard deviation of the NN interval (SDNN) was decreased in MDD group than normal control group, but was not significant ($32.82{\pm}14.33$ ms vs. $40.36{\pm}21.40$ms, p=0.078). ApEn (Approximate Entrophy) was significantly increased in MDD group than normal control group ($1.13{\pm}0.11$ vs. $0.91{\pm}0.18$, p<0.001). ApEn was correlated with LDL level (r=0.277, p=0.028), HAM-D scores (r=0.534, p<0.001) and HAM-A scores (r=0.470, p<0.001). Conclusions: MDD patients showed increased ApEn, one of the HRV measurement. And this ApEn was correlated with LDL, HAM-D and HAM-A scores. In this study, the analysis of ApEn would be a useful test of MDD.

• Sleep Medicine and Psychophysiology
• /
• v.21 no.2
• /
• pp.69-73
• /
• 2014

Objectives: This study was designed to assess the change of heart rate variability (HRV) at resting, upright, and psychological stress in anxiety disorder patients. Methods: HRV was measured at resting, upright, and psychological stress states in 60 anxiety disorder patients. We used visual analogue scale (VAS) score to assess tension and stress severity. Beck depression inventory (BDI) and state trait anxiety inventories I and II (STAI-I and II) were used to assess depression and anxiety severity. Differences between HRV indices were evaluated using paired t-tests. Gender difference analysis was accomplished with ANCOVA. Results: SDNN (Standard deviation of normal RR intervals) and low frequency/high frequency (LF/HF) were significantly increased, while NN50, pNN50, and normalized HF (nHF) were significantly decreased in the upright position compared to resting state (p < 0.01). SDNN, root mean square of the differences of successive normal to normal intervals, and LF/HF were significantly increased, while nHF was significantly decreased in the psychological stress state compared to resting state (p < 0.01). SDNN, NN50, pNN50 were significantly lower in upright position compared to psychological stress and nVLF, nLF, nHF, and LF/HF showed no significant differences between them. Conclusion: The LF/HF ratio was significantly increased after both physical and psychological stress in anxiety disorder, but did not show a significant difference between these two stresses. Significant differences of SDNN, NN50, and pNN50 without any differences of nVLF, nLF, nHF, and LF/HF between two stresses might suggest that frequency domain analysis is more specific than time domain analysis.

• Sleep Medicine and Psychophysiology
• /
• v.25 no.1
• /
• pp.15-20
• /
• 2018

Objectives: This study was designed to assess the change of heart rate variability (HRV) at resting, upright, and psychological stress states in depressive disorder patients. Methods: HRV was measured at resting, upright, and psychological stress states in 62 depressive disorder patients. We used visual analogue scale (VAS) score to assess tension and stress severity. Beck depression inventory (BDI) and state trait anxiety inventories I and II (STAI-I and II) were used to assess depression and anxiety severity, respectively. Differences between HRV indices and VAS score were evaluated using paired t-tests. Gender difference analysis was conducted with ANCOVA. Results: SDNN (standard deviation of normal to normal intervals), LF/HF (low frequency/high frequency), and VLF (very low frequency) were significantly increased, while NN50 and pNN50 were significantly decreased in the upright position compared to resting state. SDNN, RMSSD (root mean square of the differences of successive normal to normal intervals), and VLF were significantly increased, while pNN50 was significantly decreased in the psychological stress state compared to resting state. SDNN, NN50, and pNN50 were significantly lower in an upright position compared to a state of psychological stress, and LF, HF, and LF/HF showed no significant differences Conclusion: The LF/HF ratio was significantly increased after physical stress in depressive disorder. However, the LF/HF ratio was not significantly increased after psychological stress, and the change in LF/HF ratio after physical stress and psychological stress did not significantly differ from each other. Significant increase in SDNN, NN50, and pNN50 in an upright posture compared to psychological stress suggests that depressive patients react more sensitively to physical stress than psychological stress.

• Science of Emotion and Sensibility
• /
• v.22 no.3
• /
• pp.21-34
• /
• 2019

This study was an examination of the relevance and clinical significance of electroencephalographic (EEG) indexes (e.g., mental/physical stress and attention) and indexes of heart rate variability (HRV) with regard to cognitive function and physiological health conditions in elderly people. A device was used to record two-channel EEGs of the frontal lobe and a one-channel ECG simultaneously. Subjects were 76 people average aged 73. The significant findings are as follows: First, subjects whose intrinsic alpha rhythm had high amplitude, regardless of peak, showed higher resistance to mental stress and lower physical stress than did subjects with low-amplitutde intrinsic alpha rhythm. Second, HRV, SDNN, and RMSSD indexes showed strong positive correlations between the two groups of subjects regardless of the division of groups. Third, the alpha asymmetry of the left and right sides of the brain in subjects with low-amplitude intrinsic alpha rhythm was larger, and the delta/alpha ratio (reflecting physical stress) and theta/sensorimotor rhythm (SMR) ratio (showing the decline in attention) were bigger. Fourth, the subjects in whom intrinsic alpha rhythm peak occurred during slow rhythm had a higher theta/SMR ratio than did subjects whose peak occurred during fast rhythm, which was related to a steeper decline in attention. Therefore, the presence or absence of intrinsic alpha rhythm peak and amplitude on quantitative EEG may be an index reflecting the cognitive function and physiological health of elderly people.

• Science of Emotion and Sensibility
• /
• v.8 no.2
• /
• pp.95-101
• /
• 2005

This study is based on previous information regarding reduced cardiac vagal activity in patients with coronary artery disease(CAD), on reduced variance(SDNN : standard deviation of all normal RR intervals), low-frequency power(LF), and the complexity of heart rate variability(HRV) in patients with chronic heart failure(CHF), and on the normalized high-frequency power of HRV is the highest in the right lateral decubitus position among 3 recumbent postures in patients with CAD, However, nothing is known about the nonlinear dynamics of HRV for the 3 recumbent postures in patients with CAD. To investigate the linear and non-linear characteristics of HRV in patients with CAD, 29 patients as CAD group and 23 patients as control group were studied. Electrocardiogram(ECG) with lead II channel was measured on these patients for 3 recumbent postures in random order. The HRV from ECG was analyzed with linear method(for time and frequency domains) and nonlinear method. The lower the high-frequency power in normalized unit(nHF) in the supine or left lateral decubitous position, the higher the increase in nHF when the position was changed from supine or left lateral decubitous to right lateral decubitous. Among the 3 recumbent postures in patients with severe CAD, the right lateral decubitus position was observed to induce the highest vagal modulation, the lowest sympathetic modulation, and the highest complexity of human physiology system.

• Science of Emotion and Sensibility
• /
• v.17 no.3
• /
• pp.29-38
• /
• 2014

The purpose of this study was to verify human physiological responses to emotional lighting system using LED (light emitting diode) flat lighting. Subjects were ten males in their twenties without medical history to eyes. Colors of LED lighting are red, orange, yellow, green, blue, purple and colorless (white). They were stimulated by LED lighting for 5 minutes. We measured body temperature, heart rate variability (HRV) and electroencephalogram (EEG) before and after color stimulus. In case of EEG analysis, relative power ${\alpha}$ wave ratio decreased in the groups of colorless, red and orange color light. Also, sympathetic nerve was more activated than parasympathetic nerve and the body temperature was increased in the groups of colorless, red, orange, yellow color light. On the other hand, relative power ${\alpha}$ wave ratio increased and parasympathetic nerve was more activated than sympathetic nerve and the body temperature was decreased in the groups of green, blue and purple color light. The results imply that the LED color lighting system in the realistic experiment environment. In the future, studies with compounded both colors and modes according to situation or auditory as nature sound or olfactory as aroma will be required.

• Korean Journal of Psychosomatic Medicine
• /
• v.31 no.2
• /
• pp.108-117
• /
• 2023

Objectives : Somatic symptom disorder (SSD) is characterized by the manifestation of a variety of physical symptoms, but little is known about differences in autonomic nervous system activity according to symptom severity, especially within patient groups. In this study, we examined differences in heart rate variability (HRV) across symptom severity in a group of SSD patients to analyze a representative marker of autonomic nervous system changes by symptoms severity. Methods : Medical records were retrospectively reviewed for patients who were diagnosed with SSD based on DSM-5 from September 18, 2020 to October 29, 2021. We applied inverse probability of treatment weighting (IPTW) methods to generate more homogeneous comparisons in HRV parameters by correcting for selection biases due to sociodemographic and clinical characteristic differences between groups. Results : There were statistically significant correlations between the somatic symptom severity and LF (nu), HF (nu), LF/HF, as well as SD1/SD2 and Alpha1/Alpha2. After IPTW estimation, the mild to moderate group was corrected to 27 (53.0%) and the severe group to 24 (47.0%), and homogeneity was achieved as the differences in demographic and clinical characteristics were not significant. The analysis of inverse probability weighted regression adjustment model showed that the severe group was associated with significantly lower RMSSD (β=-0.70, p=0.003) and pNN20 (β=-1.04, p=0.019) in the time domain and higher LF (nu) (β=0.29, p<0.001), lower HF (nu) (β=-0.29, p<0.001), higher LF/HF (β=1.41, p=0.001), and in the nonlinear domain, significant differences were tested for SampEn15 (β=-0.35, p=0.014), SD1/SD2 (β=-0.68, p<0.001), and Alpha1/Alpha2 (ß=0.43, p=0.001). Conclusions : These results suggest that differences in HRV parameters by SSD severity were showed in the time, frequency and nonlinear domains, specific parameters demonstrating significantly higher sympathetic nerve activity and reduced ability of the parasympathetic nervous system in SSD patients with severe symptoms.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.7
• /
• pp.1093-1101
• /
• 2013

This paper demonstrates that 'Qi Energy Healing' effects on elevation of capabilities in regards with the autonomic nervous system which prevents from the stress. Nineteen participants were assigned into 'Qi Energy Healing' and the 'Ordinary Relaxation' condition. Participants were examined to see the difference of frequency domain analysis, heart rate tachogram, physical resistance through the heart rate variability. The 'Qi Energy Healing' is significantly more likely to influence on reducing and diminishing the stress. 'Qi Energy Healing' treatment showed clear distinction on 6 fact. Our findings established the link between effectiveness of 'Qi Energy Healing' and the autonomic nervous system.

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.1
• /
• pp.142-152
• /
• 2019

This study aimed to explore the association between obesity index and heart rate variability (HRV) in college-aged male smokers. A total of 85 male college students (> 10 cigarettes per day for at least 3 years) were participated in this study. According to a standardized protocol, body mass index (BMI), percent body fat (%BF), waist circumference (WC), and waist-to-hip ratio (WHR) were taken as obesity indices. Resting r-r interval was monitored for HRV analysis as an indicator of cardiac autonomic regulation. Compared with low WHR subjects, high WHR subjects had significantly lower values of rMSSD, pNN50, HF, and SD1, suggesting decreased parasympathetic activity. No such differences in LF/HF ratio were found between the WHR-based subgroups. Bivariate correlation analysis showed that obesity indices of WC, WHR, and %BF were significantly associated with rMSSD, pNN50, HF, and SD1, with a tendency for correlation coefficient to be higher with WHR than with WC or %BF. No significant association was found between BMI and HRV parameters indicative of parasympathetic activity. This study suggest that central obesity is significantly associated with decrease in parasympathetic activation, independent of BMI as an indicator of obesity, in male college smokers.

• Korean Journal of Psychosomatic Medicine
• /
• v.14 no.2
• /
• pp.94-101
• /
• 2006

Objectives : A variety of symptoms are typically reported during anxiety period, several of which are clearly linked to the autonomic nervous system(ANS), such as palpitations, chest pain and shortness of breath. Using spectral analysis of heart rate, several studies have shown that patients with anxiety disorder are characterized by a reduced heart rate variability(HRV), indicative of abnormalities in ANS fuction. To further evaluate the effect of anxiety and medication on autonomic function, 30 patients and 30 matched control subjects were assessed. Methods : Using spectral analysis of heart rate, which consisted of standardised measurements of HRV, we compared ANS between 30 patients with DSM-IV diagnosed anxiety disorder and 30 healthy controls, and investigated the autonomic effects of SSRI treatment. Five-minute HRV recordings were obtained before and after SSRI treatment and were analysed. Results : Five-minute HRV recordings in anxiety disorder patients revealed that a significant reduction in HRV was shown compared to controls. There was no significant changes in HRV between before and after SSRI treatment. Conclusion: Anxiety disorder patients showed a significant reduction in HRV compared to controls. SSRIs do not affect HRV influenced by ANS function. Further study is needed to confirm these things. Patients with anxiety disorder may suffer from functional disturbances in the interaction between the sympathetic and parasympathetic autonomic tree.