• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1674-1678
• /
• 2008

본 연구에서는 심장의 세포 변화에서부터 혈류 순환의 시스템 변화까지 일련의 과정을 시뮬레이션 할 수 있는 통합모델을 개발하였다. 본 통합 모델을 이용하여 대동맥의 탄성도 변화 따른 Pulse Wave Velocity를 추정하였으며 심근의 수축 Mechanics의 변화를 시뮬레이션 하였다. 심장은 단순한 구 형상으로 모델링 되었다. 특히 동맥순환의 특성인 Wave propagation 과 Wave deflection의 현상을 모델링하기 위해 기존 모델에서 사용된 동맥계 순환 모델을 수정하였다. 즉 기존의 동맥 모델을 1차원의 운동방정식과 연속방정식을 기반으로 하는 Distributed arterial model로 대체하였다. Distributed arterial model은 혈액의 점성에 의한 에너지 손실, 혈관의 점탄성 효과 그리고 분지 되는 혈관에서의 에너지 손실을 포함하는 정교한 동맥 순환 모델이다. 정교한 동맥계 순환 모델의 동맥 탄성도 값을 조절함으로써 탄성도 변화에 대한 PWV를 계산 할 수 있었다. 이러한 수치적 방법을 사용하여 노화에 따른 동맥벽 탄성도의 저하가 심근세포의 Cross-bridge 동역학에 미치는 영향을 시뮬레이션 하였다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.32 no.5
• /
• pp.444-450
• /
• 2008

The conventional studies of the aging effect on cardio-vascular system are mostly obtained from human experiences and can only provide local information. In this study, the effect of fatigue fracture of arterial wall on the blood pressure was investigated by hemodynamic analysis. The aging process was simulated with three stages. The pulse wave velocity increased with age. The systolic blood pressure increases consistently but diastolic blood pressure decreases with age. The simulated results show in good accordance with the clinical ones.

• The Korean Journal of Health Service Management
• /
• v.7 no.3
• /
• pp.71-82
• /
• 2013

Arterial stiffness(AS) is an important pathologic state of vascular injury. This study was carried out to elucidate the effect of physiological variables on brachial-ankle pulse wave velocity(BAPWV), index of AS. Four hundred adults(volunteers) participated in this study. Body indices, biochemical, cardiac and inflammatory markers, and right(Rt)- and left(Lt)-BAPWV were measured. Body mass index(BMI), Rt- and Lt-BAPWV, glucose, triglyceride, alkaline phosphatase(ALP), gamma-glutamyl transferase(GGT), creatinine, uric acid, troponin-I(TNI), NT-proBNP and high sensitivity C-reactive protein(hs-CRP) levels were higher than the reference value of each variable. Rt- and Lt-BAPWV were directly correlated with age, body weight, BMI, glucose, ketone, aspartate aminotransferase, alanine aminotransferase, ALP, GGT, total cholesterol, low density lipoprotein, lipoprotein(a), apolipoprotein-B, blood urea nitrogen, heart rate, TNI, creatine kinase, CK-MB, lactic dehydrogenase, myoglobin, hs-CRP, lipase, reumatoid factor, fibrinogen and D-dimer (P<0.05, P<0.01, P<0.001 or P<0.000, respectively), but inversely associated with total bilirubin, uric acid, apolipoprotein-A1 and GFR (P<0.05). These observations suggest that a variety of physiological variables may influence BAPWV, resulting in increased risk or prevention of cardiovascular and/or cerebrovascular attacks. Therefore, physiological variables affecting BAPWV should be regularly controlled.

• Journal of Korea Entertainment Industry Association
• /
• v.13 no.2
• /
• pp.197-205
• /
• 2019

This study was to compare arterial stiffness and hemodynamic responses between male smokers and non-smokers. This study also investigates the influences of smoking before exercise on arterial stiffness and hemodynamic responses. 24 male subjects of age 20-29 without history of cardiorespiratory disease were divided into smokers and non-smokers. Smokers had more than 5 years of smoking experience. In order to evaluate the effects of pre-exercise smoking, smokers were tested twice, once with a cigarette before the exercise and the other once without one. Data was collected from bio-impedance analysis, SphygmoCor XCEL, graded exercise test, and fitness test. Main results of this study are as follows: First, there are differences between smokers and non-smokers in cardiorespiratory and hemodynamic response functions, as shown by maximal oxygen consumption, exercise duration, and heart rate. Second, the although the arterial stiffness between smokers and non-smokers showed statistically significant differences in the speed of the pulse wave velocity and augmentation index, smoker had a faster rate. It shows that smoking behavior has a negative impact on the cardiovascular system. Third, pre-exercise smoking behavior does have an impact on cardiorespiratory and hemodynamic response functions, as shown by exercise duration and heart rate. Lastly, arterial stiffness between smokers and non-smokers showed statistically not significant in the speed of the pulse wave velocity and augmentation index. However, the difference was not statistically significant. Brachial systolic pressure, a component of pulse wave analysis, on the other hand, was significantly dependent on pre-exercise smoking behavior. Subjects who participated in this study are college students in early 20s. Given their relatively short history of smoking, it is possible that their smoking habits are not severe enough to develop into cardiorespiratory or cardiovascular diseases. But Smokers showed lower levels of cardiopulmonary functions, as maximal oxygen consumption and exercise duration than nonsmokers.

• Korean Journal of Clinical Laboratory Science
• /
• v.51 no.3
• /
• pp.277-285
• /
• 2019

An inverse correlation between obesity and arterial stiffness has been reported, but there are no consistent results in elderly subjects. This study examined the relationship between the arterial stiffness measured by the CAVI (cardio-ankle vascular index) and BMI (body mass index) in healthy elderly people. This study included 629 healthy elderly people aged 65 and over who underwent health examinations at a general hospital in Gyeonggi from July 2018 to June 2019. Metabolic syndrome was diagnosed using the criteria of the Adult Treatment Panel (ATP) III of the US National Cholesterol Education Program (NCEP). Among the criteria of NCEP-ATP III, the waist circumference and obesity criteria were based on the WHO criteria. All subjects underwent a biochemical blood test and an assessment of the CAVI. In both men and women, the CAVI was lower in the obese group than in the normal weight group. Gender (P=0.047), age (P<0.001), BMI (P<0.001), and waist circumference (P=0.008) were factors affecting the CAVI. Gender, high blood pressure, and hyperglycemia were independent positive predictors of the CAVI levels, while obesity was a negative predictor. Therefore, the CAVI and BMI showed an inverse correlation. In conclusion, there was an inverse correlation between the CAVI and BMI in the elderly, and obesity was a negative predictor of the CAVI.

• Korean Journal of Exercise Nutrition
• /
• v.24 no.4
• /
• pp.34-43
• /
• 2020

[Purpose] The purpose of this study was to assess changes in blood glucose level, blood pressure, and arterial stiffness after a 75 g oral glucose tolerance test (OGTT) in elderly women aged over 65 years with hypertension and either normal glycemic control, impaired fasting glucose tolerance, or diabetes mellitus. We also wished to investigate the relationship between stages of diabetes and physical fitness. [Methods] A total of 24 elderly women with hypertension were assigned to a control group (CON; n=7), impaired fasting glucose group (IFG; n=9), and diabetes mellitus group (DM; n=8). In each group, blood glucose level, brachial ankle pulse wave velocity (PWV), and blood pressure were measured at baseline as well as 60 and 120 minutes after a 75 g OGTT. Physical fitness factors such as hand grip strength, balance test, 4 m gait speed test, chair stand test, short physical performance battery, and 6-minute walking test were subsequently assessed. [Results] In all three groups, blood glucose levels were significantly increased at 60 and 120 minutes after a 75 g OGTT. In the DM group, blood glucose levels were significantly higher before and after a 75 g OGTT than in the CON group. In the CON group, PWV was significantly increased at 60 minutes after a 75 g OGTT; however, there were no changes in other groups after glucose ingestion. In the CON group, systolic and diastolic blood pressures were significantly decreased at 60 and 120 minutes after a 75 g OGTT compared to baseline. However, there was no change in blood pressure after ingestion in the DM group. The IFG group had greater grip strength than the CON group; however, there were no differences in other variables between the groups. [Conclusion] After a 75 g OGTT, elderly women with hypertension and diabetes maintain higher blood glucose levels compared to those with hypertension alone. Unlike elderly women with hypertension alone, those with hypertension and diabetes did not show changes in arterial stiffness and blood pressure after a 75 g OGTT. Therefore, elderly women with hypertension and diabetes may not be able to control their blood vessels following a 75 g OGTT due to impaired vascular endothelial function. Moreover, there was no association between diabetes stage and physical fitness in elderly women with hypertension.

• Journal of Ginseng Research
• /
• v.34 no.3
• /
• pp.212-218
• /
• 2010

Korean red ginseng (KRG) has been shown to enhance endothelium-dependent vasorelaxation in experimental animals; however, little is known about its pharmacological effects on vascular stiffness in patients with coronary artery disease (CAD). This randomized, double-blind, placebo-controlled crossover trial was carried out to determine whether KRG has beneficial effects on arterial stiffness, cardiovascular risk factors such as plasma lipid profiles and blood pressure (BP), and Rho-associated kinase (ROCK) activity. Twenty patients (mean age, 62.5 years) with stable angina pectoris were given KRG (2.7 g/day) and a placebo alternatively for 10 weeks. Blood biochemical analysis and pulse wave velocity (PWV) recording were performed on day 0 and after the completion of each treatment. ROCK activity was assessed based on the level of phospho-$Thr^{853}$ in the myosin-binding subunit of myosin light chain phosphatase, determined by Western blot analysis of peripheral blood mononuclear cells. KRG significantly decreased the systolic BP, brachial ankle PWV, and heart femoral PWV in the patients (all p<0.05), but did not significantly alter the serum lipid profiles, including triglycerides and total, high-density lipoprotein, and low-density lipoprotein cholesterol levels. The ROCK activity tended to decrease (p=0.068) following KRG treatment. The placebo did not significantly alter any of the variables. In conclusion, KRG decreased systolic BP and arterial stiffness, probably via the inhibition of ROCK activity, in patients with CAD, but had a neutral effect on serum lipid profiles. Our data suggest that KRG has a therapeutic effect on CAD.

• The Journal of the Society of Stroke on Korean Medicine
• /
• v.7 no.1
• /
• pp.17-22
• /
• 2006

Objectives : Uwhangchungsimwon (UC) is one of the famous herbal medicine frequently used for stroke, hypertension, and atherosclerosis, etc. Therefore, we intended to examine if UC could have therapeutic effect on arterial stiffness by assessing Cardio-Ankle Vascular lndex (CAVI). Methods : We enrolled 38 healthy male subjects (28±4.41 years old) and divided them into two groups (UC and control group). The UC group (N=22) were treated with 1 pill of UC and monitored by CAVI every hour for 6 hours. The control group(N=16) did not receive any medicine and were also monitored by CAVI the same manner as the UC group. In both group, we also assessed each subject's Yin-Yang pattern score by the diagnostic scoring system. In analysis, we compared the difference of CAVIs between the UC and the control group considering subject's Yin-Yang pattern. Results : There was no significant difference in the change of CAVI between the UC and the control group. After excluding Yang-pattern subjects in both group, however, we could observe that CAVI decreased significantly 5 hours after UC administration compared with the corresponding CAVI in the control group (P=0.025). In the repeated measure analysis, the between-subjects effect had statistical significance (P=0.035). Conclusion : According to these results, we suggest that UC have therapeutic effect on arterial stiffness especially after taking oriental medical diagnosis into consideration.

• Journal of Biomedical Engineering Research
• /
• v.38 no.3
• /
• pp.95-101
• /
• 2017

In this study, photoplethysmography(PPG) was suggested as a way to replace the ankle-brachial index(ABI) in diagnosing PAD. The method using the PPG was presented for the simplification of the PAD diagnosis method which was used before. And the index related to the health condition of the artery from the PPG measured in both big toes of the subjects through the experiment was drawn. The indexes showing the significant relativeness in the Pearson correlation analysis with the ABI were the stiffness index(SI), reflection index(RI); it was confirmed each of them had the correlation coefficient of 0.688, and 0.637 at p < 0.05. The explanation ability of the linear regression equation derived using ABI, SI and RI was 52.5%. The explanation ability of the secondary curve regression equation derived using ABI, squared SI was 54.7%. It is expected to provide patients with significant results and draw the index associated with PAD by measuring PPG easily in the real life instead of the ambulatory care field.

• Clinical and Experimental Pediatrics
• /
• v.57 no.5
• /
• pp.217-221
• /
• 2014

Purpose: The aim of this study was to determine whether school-aged children with Kawasaki disease (KD) have an increased risk for early atherosclerosis. Methods: The study included 98 children. The children were divided into the following groups: group A (n=19), KD with coronary arterial lesions that persisted or regressed; group B (n=49), KD without coronary arterial lesions; and group C (n=30), healthy children. Anthropometric variables and the levels of biochemical markers, including total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A, apolipoprotein B, homocysteine, highsensitivity C-reactive protein (hs-CRP), and brachial artery stiffness using pulse wave velocity were compared among the three groups. Results: There were no significant differences in blood pressure and body index among the three groups. Additionally, there was no sex-specific difference. Moreover, the levels of triglyceride, HDL-C, apolipoprotein A, and hs-CRP did not differ among the three groups. However, the levels of total cholesterol (P =0.018), LDL-C (P =0.0003), and apolipoprotein B (P =0.029) were significantly higher in group A than in group C. Further, the level of homocysteine and the aortic pulse wave velocity were significantly higher in groups A and B than in group C (P=0.0001). Conclusion: School-aged children after KD have high lipid profiles and arterial stiffness indicating an increased risk for early atherosclerosis.