• Clinical and Experimental Pediatrics
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• v.52 no.7
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• pp.752-755
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• 2009

It is well known that hemodynamic load is one of the most important determinants of cardiac structure and function. Circadian variations in blood pressure (BP) are usually accompanied by consensual changes in peripheral resistance and/or cardiac output. In recent years, reduction in circadian variations in BP and, in particular, loss of nocturnal decline of BP were observed in hypertensive patients with left ventricular hypertrophy (LVH). The patients with only a slight or no loss of nocturnal decline of BP were considered "non-dippers". Regression of LVH was observed after prolonged antihypertensive therapy. Restoration of the circadian rhythm of BP was also observed. However, the classification of patients into "dippers" and "non-dippers" is arbitrary and poorly standardized and repeatable, and in the recent studies, most hypertensive patients with LVH were "dippers". Therefore, we should be particularly cautious about the conclusions drawn using this index. On the other hand, reduced activity of low-pressure cardiopulmonary baroreceptors and impaired day-to-night modulation of autonomic nervous system activity were observed in patients with only LVH. Therefore, alterations in cardiac structure may impair BP modulation. On the other hand, the reverse can also be trueprimary alterations in BP modulation, through a persistently elevated afterload, can increase cardiac mass. Thus, the interrelationship between cardiac structure and BP modulation is complex. Hence, new and more specific methods of evaluating circadian changes in BP are needed to better clarify the abovementioned reciprocal influences.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.12 no.3
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• pp.307-316
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• 2005

Purpose: The purpose of this study was to identify 24 hours blood pressure variations among adults over 40 years of age. Method: The participants(50 adults) were recruited from P hospital and B company. The participants were divided into normotensive and hypertensive tendency groups and then sub-divided into non-dipper, dipper, and extreme dipper. The data were collected from April, 2003 to September, 2004 and analyzed using SPSS for Window program. Results: 1) There were significant differences in cardiovascular risk factor, systolic and diastolic blood pressures, and LDH, diet between the normotensive and hypertensive tendency groups. 2) Dippers in both groups showed a marked decrease in blood pressure during the night, but non-dippers in both groups didn't show a marked nocturnal decrease in blood pressure. 3) There were significant differences in heart rate, WHR, BMI, LDH, triglyceride, glucose, affective-oriented coping strategies between dippers and non-dippers. 4) There were significant differences in heart rate, WHR, BMI, LDH, triglyceride, affective-oriented coping strategies between dipper and non-dipper within hypertensive tendency group. Conclusion: Further studies are needed to provide effective intervention in hypertension when applying 24 hour blood pressure monitoring.

• Sleep Medicine and Psychophysiology
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• v.25 no.2
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• pp.51-57
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• 2018

Objectives: Previous studies have shown that periodic limb movements in sleep (PLMS) could be one of risk factors for cardiovascular morbidity. The purpose of this study was to investigate the association between PLMS and blood pressure changes during sleep. Methods: We analyzed data from 358 adults (176 men and 182 women) aged 18 years and older who were free from sleep apnea syndrome (Respiratory Disturbance Index < 5) and sleep disorders such as REM sleep behavior disorder or narcolepsy. Demographic characteristics, polysomnography records, and clinical variable data including blood pressure, body mass index, alcohol, smoking, and current medications were collected. In addition, self-report questionnaires including the Beck Depression Index, Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index were completed. Blood pressure change from bedtime to awakening was compared between the two periodic limb movement index (PLMI) groups [low PLMI ($PLMI{\leq}15$) and high PLMI (PLMI > 15)]. Blood pressure change patterns were compared using repeated measures analysis of variance. Results: Systolic blood pressure in the high PLMI group was lower than that in the low PLMI group (p = 0.036). These results were also significant when adjusted for gender and age, but were not statistically significant when adjusted for BMI, alcohol, smoking, anti-hypertension medication use and sleep efficiency (p = 0.098). Systolic blood pressure dropped by 9.7 mm Hg in the low PLMI group, and systolic blood pressure in the high PLMI group dropped by 2.9 mm Hg. There was a significant difference in delta systolic blood pressure after sleep between the two groups in women when adjusted for age, BMI, alcohol, smoking, antihypertensive medication use and sleep efficiency (p = 0.023). Conclusion: PLMS was significantly associated with a decreasing pattern in nocturnal BP during sleep, and this association remained significant in women when adjusted for age, BMI, alcohol, smoking, antihypertension medication use and sleep efficiency related to blood pressure. We suggest that PLMS may be associated with cardiovascular morbidity.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.3
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• pp.106-110
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• 2014

Obstructive sleep apnea-hypopnea (OSAH) is known to be related to nocturnal blood pressure (BP) and hypertension. The aim of this study was to evaluate the prevalence of hypertension according to the apnea-hypopnea grading. A total of 2,210 adults with snoring and obstructive sleep apnea were referred to our sleep center from July 2009 to May 2013. Clinical blood pressure (BP) was measured before sleeping (bedtime BP) and immediately after waking up in the next morning (morning BP). Subjects were classified into four groups based on the apnea-hypopnea index (AHI) from PSG as follows: control group (n=470) simple snoring and with AHI<5; mild group (n=577) with $AHI{\geq}5$ and <15; moderate group (n=508) $AHI{\geq}15$ and <30; and severe group (n=655) with $AHI{\geq}30$. The differences and correlations between BP and PSG parameters according to the AHI groups were analyzed. Patient's were classified as nomentensive (blood pressure <120/90 mmHg, n=700), prehypertensive (blood pressure < $140-120{\leq}mmHg$, n=1297) hypertensive (blood pressure ${\geq}140/90mmHg$, n=214) according to the office blood pressure measurements. The comparison of sleep parameters showed that OSA groups had a significantly higher stage N1 (control group vs. moderate OSA, severe OSA; $66.4{\pm}30.7$ vs. $85.5{\pm}36.6$, $128.4{\pm}57.3$, p<0.001) and total arousal number (control vs. moderate OSA, severe OSA; $110.7{\pm}47.7$ vs. $150.8{\pm}56.6$, $236.6{\pm}95.8$, p<0.001) compared to control group. The comparison of sleep parameters showed that OSA groups had a significantly lower stage N2 (control group vs. moderate OSA, severe OSA; $172.6{\pm}47.2$ vs. $150.7{\pm}50.5$, $120.3{\pm}57.4$, p<0.001), stage N3 (control group vs. moderate OSA, severe OSA; $38.4{\pm}33.4$ vs. $27.4{\pm}26.0$, $56.1{\pm}27.5$, p<0.001), REM (control group vs. moderate OSA, severe OSA; $64.3{\pm}25.5$ vs. $56.1{\pm}27.5$, $47.3{\pm}25.9$, p<0.001) and mean SaO2% (control group vs. moderate OSA, severe OSA; $90.0{\pm}3.5$ vs. $82.5{\pm}5.5$, $70.0{\pm}8.8$, p<0.001) compared to control group. The Apnea-hypopnea index was significantly higher in OSA groups, increased systolic and diastolic blood pressure than in the nomentensive group (bed time systolic pressure vs. AHI; <120 vs. 120-139, 140-159, >159; $17.5{\pm}18.6$ vs. $24.9{\pm}21.0$, $31.0{\pm}25.7$, $42.3{\pm}31.7$, p<0.001), (bed time diastolic pressure vs. AHI; 60-79 vs. 80-89, 90-99, >99; $19.3{\pm}19.7$ vs. $22.4{\pm}20.3$, $29.8{\pm}23.3$, $38.8{\pm}28.5$, p<0.001). AHI was positively correlated with morning systolic pressure, diastolic pressure, bed time systolic pressure and diastolic pressure (r=0.314, 0.279, 0.233 and 0.200, respectively, p<0.001). We conclude that BMI, Age, neck circumference and AHI increase with the blood pressure.

• Childhood Kidney Diseases
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• v.15 no.2
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• pp.154-162
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• 2011

Purpose: With increasing prevalence of hypertension (HTN) in children and adolescent, pediatricians have become more interested in blood pressure (BP) measurements. The ambulatory blood pressure monitoring (ABPM) is known to be useful to differentiate true HTN and white coat HTN. The object of this study is to assess the clinical usefulness of ABPM in Korean children and adolescents. Methods: A retrospective review of 51 patients in Kyungpook National University Hospital from January 2002 to February 2010 was done. All patients were 6-18 years old and underwent ABPM. We calculated the mean value of ABP, BP load, nocturnal dip and compared the results with the patients' diagnosis and characteristics. Results: The mean age of the 51 patients was $17.8{\pm}1.8$ years and 19 children were obese. 37 patients (72.5%) were truly hypertensive and 1 patient was diagnosed as masked HTN and 7 children (14%) as white coat HTN. The rest of the patients were normotensive. Among patients with white coat HTN, 5 were in a prehypertensive state. Mean systolic and diastolic BP load of patients with true HTN were significantly higher than non-hypertensive children (P<0.001). Although the nocturnal dip of all patients were below 10%, there was no statistical significance. The obese patients showed higher systolic and diastolic BP. Their systolic and diastolic BP load were significantly higher than non-obese patients (P<0.001). Conclusion: ABPM in children and adolescents seems to be a valuable tool in the assessment of white coat HTN and in the confirmation of true HTN. A considerable number of white coat HTN patients are revealed to be in a prehypertensive state and need close follow-up.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.153-168
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• 1998

Background: The existing data indicate that obstructive sleep apnea syndrome contributes to the development of cardiovascular dysfunction such as systemic hypertension and cardiac arrhythmias, and the cardiovascular dysfunction has a major effect on high long-term mortality rate in obstructive sleep apnea syndrome patients. To a large extent the various studies have helped to clarify the pathophysiology of obstructive sleep apnea, but many basic questions still remain unanswered. Methods: In this study, the influence of obstructive sleep apnea on systemic blood pressure, cardiac rhythm and urinary catecholamines concentration was evaluated. Over-night polysomnography, 24-hour ambulatory blood pressure and ECG monitoring, and measurement of urinary catecholamines, norepinephrine (UNE) and epinephrine (UEP), during waking and sleep were undertaken in obstructive sleep apnea syndrome patients group (OSAS, n=29) and control group (Control, n=25). Results: 1) In OSAS and Control, UNE and UEP concentrations during sleep were significantly lower than during waking (P<0.01). In UNE concentrations during sleep, OSAS showed higher levels compare to Control (P<0.05). 2) In OSAS, there was a increasing tendency of the number of non-dipper of nocturnal blood pressure compare to Control (P=0.089). 3) In both group (n=54), mean systolic blood pressure during waking and sleep showed significant correlation with polysomnographic data including apnea index (AI), apnea-hypopnea index (AHI), arterial oxygen saturation nadir ($SaO_2$ nadir) and degree of oxygen desaturation (DOD). And UNE concentrations during sleep were correlated with AI, AHI, $SaO_2$ nadir, DOD and mean diastolic blood pressure during sleep. 4) In OSAS with AI>20 (n==14), there was a significant difference of heart rates before, during and after apneic events (P<0.01), and these changes of heart rates were correlated with the duration of apnea (P<0.01). The difference of heart rates between apneic and postapneic period (${\Delta}HR$) was significantly correlated with the difference of arterial oxygen saturation between before and after apneic event (${\Delta}SaO_2$) (r=0.223, P<0.001). 5) There was no significant difference in the incidence of cardiac arrhythmias between OSAS and Control In Control, the incidence of ventricular ectopy during sleep was significantly lower than during waking. But in OSAS, there was no difference between during waking and sleep. Conclusion : These results suggested that recurrent hypoxia and arousals from sleep in patients with obstructive sleep apnea syndrome may increase sympathetic nervous system activity, and recurrent hypoxia and increased sympathetic nervous system activity could contribute to the development of cardiovascular dysfunction including the changes of systemic blood pressure and cardiac function.

• Journal of Biomedical Engineering Research
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• v.35 no.4
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• pp.95-98
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• 2014

The baroreflex is one kind of homeostatic mechanisms to regulate acute blood pressure (BP) changes by controlling heartbeat interval (HBI). To quantify the effect of baroreflex, we suggested a new approach of analyzing Granger causality between systolic BP (SBP) and HBI. The index defined as baroreflex effectiveness (BRE) was generated by the hypothesis that more effectual baroreflex would be related to more effective Granger causal influence of SBP on HBI. Six obstructive sleep apnea (OSA) patients (apnea-hypopnea index, AHI ${\geq}5$ events/hr) and six normal subjects participated in the study. Their SBP and HBI during nocturnal sleep were obtained from a non-invasive continuous BP measurement device. While the BRE ($mean{\pm}SD$) of normal subjects was $47.0{\pm}4.0%$, OSA patients exhibited the BRE of $34.0{\pm}3.8%$. The impaired baroreflex function of OSA patients can be explained by the physiological mechanism associated with recurrent hypoxic episodes during sleep. Thus, the significantly lower BRE in OSA patients verified the availability of Granger causality analysis to evaluate baroreflex during sleep. Furthermore, the range of BRE obtained from normal subjects was not overlapped with that obtained from OSA patients. It suggests the potential of BRE as a new helpful tool for diagnosing OSA.

• Sleep Medicine and Psychophysiology
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• v.9 no.1
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• pp.24-33
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• 2002

Objectives: Nasal continuous positive airway pressure (CPAP) corrected elevated blood pressure (BP) in some studies of obstructive sleep apnea syndrome (OSAS) but not in others. Such inconsistent results in previous studies might be due to differences in factors influencing the effects of CPAP on BP. The factors referred to include BP monitoring techniques, the characteristics of subjects, and method of CPAP application. Therefore, we evaluated the effects of one night CPAP application on BP and heart rate (HR) reactivity using non-invasive beat-to-beat BP measurement in normotensive and hypertensive subjects with OSAS. Methods: Finger arterial BP and oxygen saturation monitoring with nocturnal polysomnography were performed on 10 OSAS patients (mean age $52.2{\pm}12.4\;years$; 9 males, 1 female; respiratory disturbance index (RDI)>5) for one baseline night and another CPAP night. Beat-to-beat measurement of BP and HR was done with finger arterial BP monitor ($Finapres^{(R)}$) and mean arterial oxygen saturation ($SaO_2$) was also measured at 2-second intervals for both nights. We compared the mean values of cardiovascular and respiratory variables between baseline and CPAP nights using Wilcoxon signed ranks test. Delta ($\Delta$) BP, defined as the subtracted value of CPAP night BP from baseline night BP, was correlated with age, body mass index (BMI), baseline night values of BP, BP variability, HR, HR variability, mean $SaO_2$ and respiratory disturbance index (RDI), and CPAP night values of TWT% (total wake time%) and CPAP pressure, using Spearman's correlation. Results: 1) Although increase of mean $SaO_2$ (p<.01) and decrease of RDI (p<.01) were observed on the CPAP night, there were no significant differences in other variables between two nights. 2) However, delta BP tended to increase or decease depending on BP values of the baseline night and age. Delta systolic BP and baseline systolic BP showed a significant positive correlation (p<.01), but delta diastolic BP and baseline diastolic BP did not show a significant correlation except for a positive correlation in wake stage (p<.01). Delta diastolic BP and age showed a significant negative correlation (p<.05) during all stages except for REM stage, but delta systolic BP and age did not. 3) Delta systolic and diastolic BPs did not significantly correlate with other factors, such as BMI, baseline night values of BP variability, HR, HR variability, mean SaO2 and RDI, and CPAP night values of TWT% and CPAP pressure, except for a positive correlation of delta diastolic pressure and TWT% of CPAP night (p<.01). Conclusions: We observed that systolic BP and diastolic BP tended to decrease, increase or remain still in accordance with the systolic BP level of baseline night and aging. We suggest that BP reactivity by CPAP be dealt with as a complex phenomenon rather than a simple undifferentiated BP decrease.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.2
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• pp.73-76
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• 2013

Uvulopalatopharyngoplasty (UPPP) is one possibility for the treatment of Obstructive Sleep Apnea (OSA). The aim of this study was study the analysis of polysomnography of pre-UPPP and post-UPPP. All patients were evaluated by means of a physical examination, the epworth sleepiness scale (ESS), the beck depression inventory (BDI) and the nocturnal polysomnography (PSG) before surgery, and 6~12 months after surgery. A total of 15 patients were investigated. All underwent UPPP. The patients were between 26 and 62 years old ($mean{\pm}SD$; $39.7{\pm}10.9$) with a lean body mass index (BMI) of $mean{\pm}SD$; $26.2{\pm}3.0kg/m^2$. The comparison of sleep questionnaires showed that after UPPP, the patients had a significantly lower BMI ($26.2{\pm}3.0kg/m^2$ vs $26.0{\pm}3.4kg/m^2$, p=0.241), ESS ($10.0{\pm}5.4$ vs $6.9{\pm}3.2$, p=0.022), BDI ($9.2{\pm}8.2$ vs $4.2{\pm}4.3$, p=0.343) and higher blood pressure ($127.5{\pm}12.1$ vs $123.7{\pm}12.0$, p=0.272) compared to before UPPP. The comparison of sleep parameters showed that after UPPP, patients had a significantly lower stage N1 ($108.8{\pm}53.1$ vs $82.2{\pm}48.9$, p=0.016), lower sleep latency ($4.9{\pm}4.4$ vs $2.0{\pm}1.7$, p=0.083), a lower total arousal number ($210.6{\pm}90.3$ vs $147.1{\pm}87.3$, p=0.019), lower oxygen desaturation index (ODI) ($30.2{\pm}20.9$ vs $10.2{\pm}15.1$, p=0.006), lower apnea-hypopnea index (AHI) ($31.6{\pm}22.4$ vs $10.9{\pm}15.4$, p=0.005), and a lower respiratory disturbance index (RDI) ($37.4{\pm}21.3$ vs $18.5{\pm}16.5$, p=0.008) compared to after UPPP. The comparison of sleep parameters showed that after UPPP, patients had a significantly higher stage N2 ($154.0{\pm}39.9$ vs $180.5{\pm}49.5$, p=0.017), higher REM ($58.5{\pm}29.7$ vs $72.6{\pm}34.0$, p=0.249), higher $meanSaO_2$ ($94.3{\pm}2.0$ vs $95.9{\pm}0.9$, p=0.043), and higher $meanSaO_2$ ($79.3{\pm}8.5$ vs $83.1{\pm}7.9$, p=0.116) than before UPPP. After UPPP, 6 patients were cured, 2 showed marked improvement, and 7 did not improve. After surgery, the success of the treatment was at 53%. The subjective patient satisfaction was higher than before the surgery.

• The Korean Journal of Physiology
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• v.11 no.1
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• pp.27-32
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• 1977

Diospyros Kaki Thunberg is the species of persimmon tree that grows in Korea. Although its fresh or dried fruits are often served as a desert, it has little been known if persimmon tree has any specific pharmacological action. The leaves and branches of persimmon tree has long been used as folk remedies for palsy and frostbite in the southern part of Korea and it is also in use for the treatment of hiccup and nocturnal enuresis in chinese herbal medicine. Recently it was reported that an intravenous administration of Diospyros Kaki Thunberg ethanol extract (KTEE) into the animals lowered arterial blood pressure. Lee concluded from his study on the mechanism of depressor action of KTEE that at least a part of depressor response he observed was caused by acetylcholine-like action of KTEE. On the other hand little study has been made on the effect of KTEE on the motility of isolated animal intestines. Therefore the present study was undertaken to investigate effect of KTEE and the mechanism of its action on the motility of isolated rabbit duodenum. Ethanol extract of Diospyros Kaki Thunberg was prepared by boiling 1 kg of dried branches of persimmon tree in 1 liter of ethanol and the motility of isolated rabbit duodenum was recorded on physiograph by means of force transducer connected with Magnus apparatus. Doses of KTEE used were $5{\times}10^{-4}gm/ml,\;1{\times}10^{-3}gm/ml,\;and\;2{\times}10^{-3}gm/ml$. And the isolated duodenum was separately pretreated with acetylcholine $(5{\times}10^{-7}gm/ml)$, pilocarpine $(2.5{\times}10^{-6}gm/ml)$, histamine $(5{\times}10^{-6}gm/ml)$ and barium chloride $(2.5{\times}10^{-5}gm/ml)$ in order to find out interactions of these drugs with KTEE. The results obtained are as follows: 1. At doses of $5{\times}10^{-4}gm/ml,\;1{\times}10^{-3}gm/ml$ KTEE reduced contractions of isolated duodenum, while tonus as well as contaction of duodenum were depressed with $2{\times}10^{-3}gm/ml$ of KTEE. 2. Since the inhibitory effect of KTEE on the intestinal motility was not blocked by pretreatment with acetylcholine, pilocarpine, and barium chloride, it was strongly suggested that the inhibitory action of KTEE on intestinal motility is mainly Caused by its antihistamine effect. 3. It is also concluded that the principal substance of KTEE responsible for inhibition of intestinal motility may also have a vasodilating activity and would not be an acetylcholine-like substance in case it is same substance as that cause depressor responses.