• Korean Journal of Exercise Nutrition
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• v.25 no.1
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• pp.35-41
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• 2021

[Purpose] This pilot study aimed to develop a regression model to estimate the excess post-exercise oxygen consumption (EPOC) of Korean adults using various easy-to-measure dependent variables. [Methods] The EPOC and dependent variables for its estimation (e.g., sex, age, height, weight, body mass index, fat-free mass [FFM], fat mass, % body fat, and heart rate_sum [HR_sum]) were measured in 75 healthy adults (31 males, 44 females). Statistical analysis was performed to develop an EPOC estimation regression model using the stepwise regression method. [Results] We confirmed that FFM and HR_sum were important variables in the EPOC regression models of various exercise types. The explanatory power and standard errors of estimates (SEE) for EPOC of each exercise type were as follows: the continuous exercise (CEx) regression model was 86.3% (R²) and 85.9% (adjusted R²), and the mean SEE was 11.73 kcal, interval exercise (IEx) regression model was 83.1% (R²) and 82.6% (adjusted R²), while the mean SEE was 13.68 kcal, and the accumulation of short-duration exercise (AEx) regression models was 91.3% (R²) and 91.0% (adjusted R²), while the mean SEE was 27.71 kcal. There was no significant difference between the measured EPOC using a metabolic gas analyzer and the predicted EPOC for each exercise type. [Conclusion] This pilot study developed a regression model to estimate EPOC in healthy Korean adults. The regression model was as follows: CEx = -37.128 + 1.003 × (FFM) + 0.016 × (HR_sum), IEx = -49.265 + 1.442 × (FFM) + 0.013 × (HR_sum), and AEx = -100.942 + 2.209 × (FFM) + 0.020 × (HR_sum).

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.853-860
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• 2010

This study investigated differences in blood oxygen saturation($SpO_2$) and heart rate(HR) according to flow rate, gender, and phase in males and females in their 60s when the supply of 93% highly concentrated oxygen administration was changed (1L/min, 3L/min, and 5L/min). It recruited totally 20 elderly subjects including 10 males($68.0{\pm}2.6$ years) and 10 females ($65.5{\pm}3.1$ years). The experiment consisted of three phages of Rest 1(5 min), Hyperoxia(10 min), and Rest 2(10 min), and $SpO_2$[%] and HR[bpm] were measured during all phages. $SpO_2$ was higher in Hyperoxia phase supplied with highly concentrated oxygen than in Rest phases. Higher flow rate was associated with more increase in $SpO_2$. HR was reduced in Hyperoxia phase compared to Rest phases. More supply of highly concentrated oxygen was associated with more decrease of HR. However, there were no differences in both $SpO_2$ and HR according to gender.

• Journal of Nutrition and Health
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• v.40 no.3
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• pp.211-220
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• 2007

The purpose of this study was to investigate that the effect of dietary fatty acid composition on pro- and macro-glycogen utilization and resynthesis. The analyses were further extended for different muscle fibers (type I, type II, & type IIb) as well as tissues (i.e., liver & heart). Total one hundred sixty Sprague-Dawley rats were used, and rats were randomly allocated into four experimental groups: animals fed standard chow diet (n=40), animals fed saturated fatty acid diet (n=40), animals fed monounsaturated fatty acid (n=40), and animals fed polyunsaturated fatty acid (n=40). Animals in each groups were further divided into five subgroups: sacrificed at REST (n=8), sacrificed at immediately after 3 hr swim exercise (P-0HR, n=8), sacrificed at one hour after 3 hr swim exercise (P-1HR, n=8), sacrificed at four hour after 3 hr swim exercise (P-4HR, n=8), and sacrificed at twenty-four hour after 3 hr swim exercise (P-24HR, n=8). Soleus (type I), red gastrocnemius (type IIa), white gastrocnemius (type IIb), liver, and heart were dissected out at appropriated time point from all animals, and were used for analyses of pro- & macro-glycogen concentrations. After 8 weeks of dietary interventions, there was no significant difference in body mass in any of dietary conditions (p>.05). After 3 hr swim exercise, blood lactate level was higher compared to resting conditions in all groups, but it was returned to resting value after 1 hr rest (p<.05). Free fatty acid concentration was higher in all high fat fed groups(regardless of fatty acid composition) than CHOW consumed group. At rest, pro- & macro-glycogen concentration was not different from any of experimental groups (p>.05). Regardless of forms of glycogen, the highest level was observed in liver (p<.01), and most cases of supercompensation after 3hr exercise observed in this study were occurred in CHOW fed tissues. Except heart muscle, all tissues used in this study showed that pro- and macro-glycogen concentration was significantly decreased after 3 hr exercise. Based on these results, two conclusions were made: first, there is no different level of glycogen content in various tissues regardless of types of fatty acids consumed and second, the highest mobilization rate would be demonstrated from CHOW fed animals compare to animals that consumed any kinds of fatty acid diet if prolonged exercise is applied.

• Journal of Cardiovascular Imaging
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• v.26 no.4
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• pp.217-225
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• 2018

BACKGROUND: In patients with acute heart failure (AHF), diastolic dysfunction, especially pseudonormal (PN) or restrictive filling pattern (RFP) of left ventricle (LV), is considered to be implicated in a poor prognosis. However, prognostic significance of diastolic dysfunction in patients with ischemic heart disease (IHD) has been rarely investigated in Korea. METHODS: We enrolled 138 patients with IHD presenting as AHF and sinus rhythm during echocardiographic study. Diastolic dysfunction of LV was graded as ${\geq}2$ (group 1) or 1 (group 2) according to usual algorithm using E/A ratio and deceleration time of mitral inflow, E'/A' ratio of tissue Doppler echocardiography and left atrial size. RESULTS: Patients in group 1 showed higher 2-year mortality rate ($36.2%{\pm}6.7%$) than those in group 2 ($13.6%{\pm}4.5%$; p = 0.008). Two-year mortality rate of patient with LV ejection fraction (LVEF) < 40% ($26.8%{\pm}6.0%$) was not different from those with LVEF 40%-49% ($28.0%{\pm}8.0%$) or ${\geq}50%$ ($13.7%{\pm}7.4%$; p = 0.442). On univariate analysis, PN or RFP of LV, higher stage of chronic kidney disease (CKD) and higher New York Heart Association (NYHA) functional class were poor prognostic factors, but LVEF or older age ${\geq}75$ years did not predict 2-year mortality. On multivariate analysis, PN or RFP of LV (hazard ratio [HR], 2.52; 95% confidence interval [CI], 1.09-5.84; p = 0.031), higher stage of CKD (HR, 1.57; 95% CI, 1.14-2.17; p = 0.006) and higher NYHA functional class (HR, 1.81; 95% CI, 1.11-2.94; p = 0.017) were still significant prognostic factors for 2-year mortality. CONCLUSIONS: PN or RFP of LV was a more useful prognostic factor for long-term mortality than LVEF in patients with IHD presenting as AHF.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1425-1426
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• 2010

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.40-45
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• 2011

Cardiovascular changes caused by $CO_2$ pneumoperitoneum during laparoscopic ovariohysterectomy (LOVH) were measured in nine healthy mixed breed dogs ($16.7{\pm}4.6kg$). The dogs were premedicated with the combination of atropine, acepromazine, and butorphanol. General anesthesia was induced with propofol and maintained with isoflurane in oxygen. Controlled ventilation maintained partial pressure of end-tidal $CO_2$ between 35-45 mmHg. The $CO_2$ pneumoperitoneum was maintained at a constant pressure of 12 mmHg and the dog was placed in the $15^{\circ}$ Trendelenburg position as LOVH was performed. Dorsal pedal artery was catheterized for measurements of heart rate (HR) and invasive arterial blood pressure (IBP). Prior to the intraperitoneal insufflation, baseline measurements of HR and IBP were made every minute for a total of 10 min. Then, measurements of HR and IBP were made every 5 min following intraperitoneal insufflation and were also made every 5 min following desufflation for a total of 10 min. The $CO_2$ pneumoperitoneum during LOVH resulted in a significant (P < 0.05) increase in systolic arterial blood pressure at the time of the onset of insufflation. In addition, diastolic and mean arterial blood pressure increased significantly (P < 0.05) at the time of the onset of insufflation and 5 min following insufflation. The mean heart rate did not change significantly during LOVH. Although IBP showed sharp initial rise following the $CO_2$ pneumoperitoneum, the changes were within physiological acceptable limits in these healthy, ventilated dogs.

• Journal of Pharmacopuncture
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• v.22 no.2
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• pp.95-101
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• 2019

Objectives: Angiotensin II (AngII), a major product of renin-angiotensin system (RAS) has important role in induction of hypertension and antihypertensive effect of several medicinal plant was mediated by effect on this agent. Therefore, this study examined the possible effect of hydroalcoholic extract of Crocus sativus (C. sativus) on hypertension induced by AngII. Methods: Six groups (n = 6) of rats were used as follow: 1) Control, 2) AngII (300 ng/kg), 3) Losartan (Los, 10 mg/kg) + AngII and 4-6) C. sativus extract (10, 20 & 40 mg/kg,) + AngII. The femoral artery and vein were cannulated for recording cardiovascular parameters and drugs administration, respectively. All drugs were injected intravenously (i.v). Los and all doses of C. sativus injected 10 min before AngII. Systolic blood pressure (SBP), mean arterial blood pressure (MAP) and heart rate (HR) were recorded throughout the experiment and those peak changes (${\Delta}$) were calculated and compared to control and AngII. Results: AngII significantly increased ${\Delta}MAP$, ${\Delta}SBP$ and ${\Delta}HR$ than control (P < 0. 01 to P < 0.001) and these increments were significantly attenuated by Los. All doses of C. sativus significantly reduced peak ${\Delta}MAP$, ${\Delta}SBP$, and ${\Delta}HR$ than AngII group (P < 0. 05 to P < 0.001). In addition, peak ${\Delta}MAP$, ${\Delta}SBP$ in doses 10 and 20 were significant than Los + AngII group (P<0.05 to P< 0.01) but in dose 40 only MAP was significant (P<0.05). Peak ${\Delta}HR$ in all doses of C sativus was not significant than Los+ AngII. Conclusion: Regarding the improving effect of the C. sativus extract on AngII induced hypertension, it seems that this ameliorating effect partly mediated through inhibition of RAS.

• Journal of Korean Academy of Nursing
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• v.50 no.6
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• pp.740-756
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• 2020

Purpose: The purpose of this study was to evaluate the effect on blood pressure (BP) and heart rate (HR) according to aerobic exercise characteristics in adults with hypertension using a systematic review and meta-analysis. Methods: The related researches were selected from PubMed, EMBASE, Cochrane library, CINAHL, PsycINFO, SPORTDiscus and 5 domestic databases up to September 4, 2019. To estimate the effect size, random effect models were used to derive weighted mean differences (WMD) and their 95% confidence intervals (CI) of aerobic exercise on BP and HR. Results: A total of 37 RCTs with 1,813 samples were included. Aerobic exercise was found to significantly reduce systolic BP (WMD, - 8.29 mmHg; 95% CI, - 10.12 to - 6.46), diastolic BP (WMD, - 5.19 mmHg; 95% CI, - 6.24 to - 4.14) and HR (WMD, - 4.22 beats/min; 95% CI, - 5.36 to -3.09). In detail, systolic BP and diastolic BP were significantly decreased in all groups of exercise types, frequency and duration. Systolic BP and diastolic BP were significantly decreased in the moderate and vigorous-intensity group. Exercise characteristics with the most dramatical change in systolic BP were water-based training, moderate-intensity, 3 times a week and 8 to 11 weeks of duration. In diastolic BP, the greatest effect size was over 24 weeks of exercise. Conclusion: Moderate aerobic exercise, especially water-based exercise can be an important part of lifestyle modification for hypertensive patients. Also, it can be recommended in a variety of clinical settings for lowering BP and HR. However, there is insufficient evidence that low-intensity exercise is effective in lowering BP.

• Korean Journal of Exercise Nutrition
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• v.23 no.3
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• pp.22-28
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• 2019

[Purpose] The purpose of this study was to investigate the effect of diet plus exercise training and detraining for 12 weeks on body composition, aerobic performance, and stress-related variables in obese women. [Methods] Twenty-five women in their 20s-40s with 30% body fat and body mass indices above 25 kg/m² were divided into HR_LT (heart rate at lactate threshold) and HR_LT + 5% groups. Dietary intervention of 70% recommended dietary allowance (RDA) and exercise treatment composed of aerobic exercises on a bicycle (30 min) and treadmill (30 min) were then performed. These interventions were performed three times a week for 12 weeks. [Results] Dietary intake was significantly decreased, while daily activity significantly increased within the 12-week intervention period, and this effect was sustained after 12 weeks of detraining. Exercise training based on dietary intake and daily activity presented a significantly decreased weight and % body fat, improvement of aerobic performance, and a significant increase in heart rate variability (HRV) (e.g., average of all RR intervals and the square root mean squared differences of successive RR intervals) as stress-related variables. It was also confirmed that the improvement of body composition and stress-related variables were maintained even after detraining. [Conclusion] Our results suggest that 70% RDA of dietary intervention and exercise training corresponding to HR_LT and HR_LT + 5% for 12 weeks were effective in improving body composition and aerobic performance, and relieving stress. In particular, enhanced HRV persisted for up to 12 weeks after the end of exercise training in obese women.

• The Korean journal of internal medicine
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• v.39 no.1
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• pp.95-109
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• 2024

Background/Aims: Sex differences in the prognosis of heart failure (HF) have yielded inconsistent results, and data from Asian populations are even rare. This study aimed to investigate sex differences in clinical characteristics and long-term prognosis among Korean patients with HF. Methods: A total of 5,625 Korean patients hospitalized for acute HF were analyzed using a prospective multi-center registry database. Baseline clinical characteristics and long-term outcomes including HF readmission and death were compared between sexes. Results: Women were older than men and had worse symptoms with higher N-terminal pro B-type natriuretic peptide levels. Women had a significantly higher proportion of HF with preserved ejection fraction (HFpEF). There were no significant differences in in-hospital mortality and rate of guideline-directed medical therapies in men and women. During median follow-up of 3.4 years, cardiovascular death (adjusted hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.07-1.78; p = 0.014), and composite outcomes of death and HF readmission (adjusted HR, 1.13; 95% CI, 1.01-1.27; p = 0.030) were significantly higher in men than women. When evaluating heart failure with reduced ejection fraction (HFrEF) and HFpEF separately, men were an independent risk factor of cardiovascular death in patients with HFrEF. Clinical outcome was not different between sexes in HFpEF. Conclusions: In the Korean multi-center registry, despite having better clinical characteristics, men exhibited a higher risk of all-cause mortality and readmission for HF. The main cause of these disparities was the higher cardiovascular mortality rate observed in men compared to women with HFrEF.