Treadmill running suppresses the vulnerability of dopamine D₂ receptor deficiency to obesity and metabolic complications: a pilot study

( Jinkyung Cho ),( Donghyun Kim ),( Jungmoon Jang ),( Jeonghyeon Kim ),( Hyunsik Kang ) 한국운동영양학회 2018 Physical Activity and Nutrition (Phys Act Nutr) Vol.22 No.3

[Purpose] To investigate the effect of treadmill running on D2R deficiency related susceptibility to high fat diet (HFD )-induced obesity and its metabolic complications. [Methods] D2R-/- and +/- mice were obtained by backcrossing D2R+/- heterozygotes on wild type (WT) littermates (C57BL/6J background) for >10 generations. Mice were randomly assigned to 1) WT mice with standard chow (SC) (WT+SC); 2) WT mice with highfat diet (WT+HFD); 3) WT mice with high-fat diet plus exercise (WT+HFD+EX), 4) heterozygous (HET) D2R mice with SC (HET+SC); 5) heterozygous D2R mice with HFD (HET+HFD); and 6) heterozygous D₂R mice with HFD plus exercise (HET+HFD+EX). In addition, mice assigned to EX groups were subjected to running on a motor-driven rodent treadmill with a frequency of 5 days per week. [Results] After a 10-week HFD treatment, HET D2R (+/- ) mice exhibited significantly higher values for hepatic steatosis (p<0.001), areas under the curves (AUCs) for the glucose tolerance test (GTT) and the insulin tolerance test (ITT) (p<0.001 & p<0.001 respectively), serum leptin (p=0.005) and total cholesterol (TC ) (p=0.009), in conjunction with decreased locomotor activity (p=0.031), compared to HET mice exposed to standard chow. However, these HFD-induced elevations in hepatic steatosis (p<0.001), AUCs for GTT and ITT (p=0.032 & p=0.018, respectively), serum leptin (p=0.038) and TC (p=0.038) were significantly alleviated after 10 weeks of treadmill running. [Conclusion] The current findings of the study provide experimental evidence of treadmill running as an effective and non-pharmacologic strategy to treat the susceptibility of brain D2R deficiency to HFD-induced obesity and metabolic disorders.

Insulin Resistance and Its Association with Metabolic Syndrome in Korean Children

Cho, Jinkyung,Hong, Haeryun,Park, Soohyun,Kim, Shinuk,Kang, Hyunsik Hindawi 2017 BioMed research international Vol.2017 No.-

<P><B>Background</B></P><P> This study investigated the association between insulin resistance (IR) and metabolic syndrome (MetS) in children.</P><P><B> Methods</B></P><P> A cross-sectional study involving 1036 healthy children aged between 7 and 13 years was conducted. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated as an index of IR. Participants were classified according to the HOMA-IR quartiles.</P><P><B> Results</B></P><P> Incremental, linear trends were found in age (<I>p</I> < 0.001), body mass index (BMI) (<I>p</I> < 0.001), body fat (<I>p</I> < 0.001), waist circumference (<I>p</I> < 0.001), resting blood pressures (BP) (<I>p</I> < 0.001), triglycerides (TG) (<I>p</I> < 0.001), total cholesterol (TC) (<I>p</I> < 0.001), high density lipoprotein-cholesterol (HDL-C) (<I>p</I> < 0.001), FBG (<I>p</I> < 0.001), and insulin (<0.001) according to incremental HOMA-IR categories (from the 1st to 4th quartile). Compared with children in the 1st HOMA-IR quartile, children in the 4th HOMA-IR quartile had significantly higher odd ratios (ORs) of abnormalities in systolic (<I>p</I> = 0.051) and diastolic BP (<I>p</I> = 0.005), FBG (<I>p</I> < 0.001), TG (<I>p</I> < 0.001), TC (<I>p</I> = 0.016), and HDL-C (<I>p</I> = 0.006) even after adjustments for age, gender, BMI, and body fat percentage. Children in the 3rd HOMA-IR quartile had significant abnormalities in FBG (<I>p</I> < 0.001), TG (<I>p</I> = 0.001), and HDL-C (<I>p</I> = 0.010) even after adjustments for the covariates.</P><P><B> Conclusion</B></P><P> The current findings suggest that IR is significantly associated with the clustering of MetS risk factors in children in Korea. </P>

Physical activity and all-cause mortality in Korean older adults

Cho, Jinkyung,Lee, Inhwan,Park, Soohyun,Jin, Youngyun,Kim, Donghyun,Kim, Shinuk,Kang, Hyunsik Informa UK (TaylorFrancis) 2018 Annals of human biology Vol.45 No.4

Socioeconomic Status, Frailty, and All-Cause Mortality in Korean Older Adults: A 3-Year Population-Based Prospective Study

Cho, Jinkyung,Lee, Inhwan,Park, Soo Hyun,Jin, Youngyun,Kim, Donghyun,Kong, Ji Young,Kang, Hyunsik Hindawi 2017 BioMed research international Vol.2017 No.-

<P><B>Background</B></P><P> Little is known regarding the effects of socioeconomic status (SES) and frailty on mortality in Korea.</P><P><B> Objective</B></P><P> This study investigated the combined impact of low SES and frailty on all-cause mortality in Korean older adults.</P><P><B> Methods</B></P><P> Study sample at baseline comprised 7,960 community-dwelling adults (56.8% women) aged 65 years and older. The Cox proportional hazards model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of low SES and frailty for all-cause mortality.</P><P><B> Results</B></P><P> Overall, low SES plus frailty resulted in an increased risk of all-cause mortality (HR = 1.56, 95% CI = 1.09–2.23, <I>P</I> = 0.015) even after adjustments for all the measured covariates, as compared with high SES plus nonfrailty (HR = 1). Among older adults aged 65–75 years, the increased mortality risk of either low SES plus nonfrailty (HR = 1.37, 95% CI = 1.02–1.84, <I>P</I> = 0.038) or high SES plus frailty (HR = 2.09, 95% CI = 1.12–3.91, <I>P</I> = 0.021) remained significant even after adjustments for all the covariates, as compared with high SES plus nonfrailty (HR = 1).</P><P><B> Conclusion</B></P><P> The current findings suggest that either low SES or frailty is significantly associated with increased all-cause mortality in Korean older adults.</P>

Effect of Training Intensity on Nonalcoholic Fatty Liver Disease

CHO, JINKYUNG,KIM, SHINUK,LEE, SHINHO,KANG, HYUNSIK American College of Sports Medicine 2015 Medicine and science in sports and exercise Vol.47 No.8

BACKGROUND: Training intensity may play a key role in magnifying the protective effect of physical exercise against nonalcoholic fatty liver disease (NAFLD). PURPOSE: This study aimed to test the hypothesis that vigorous-intensity and interval training is as effective as moderate-intensity and continuous exercise training on NAFLD in high-fat diet (HFD)-induced obese mice. METHODS: C57BL/6 mice (N = 40) were fed a standard-chow diet (n = 10) or HFD (n = 30) for 16 wk. After the initial 8-wk dietary treatments, HFD mice were further divided into HFD only (n = 10), HFD plus vigorous-intensity and interval treadmill running (VIT) (n = 10), and HFD plus moderate-intensity and continuous treadmill running (MIT) (n = 10) for the remaining 8-wk period. RESULTS: Chronic exposure to HFD resulted in hepatic steatosis in conjunction with an obese and impaired glucose tolerance condition characterized by dyslipidemia, hyperinsulinemia elevated markers for the liver damage, and hypoadiponectinemia. Although VIT and MIT alleviated the NAFLD conditions, the former was more effective at alleviating hepatic steatosis than the latter. The intensity-dependent benefit of exercise training against hepatic steatosis was associated with greater activation of VIT on hepatic AMP-mediated protein kinase in conjunction with greater suppressive effect of VIT on hypoadiponectinemia, downregulation of the Adiponectin receptor 2 signaling pathway, and upregulation of the NF-&kgr;B signaling pathway in the liver. CONCLUSIONS: The current findings suggest that VIT is an alternative way of exercise training to combat hepatic steatosis associated with an obese and impaired glucose tolerance phenotype.

Weight Status, Physical Activity, and Depression in Korean Older Adults

Cho, Jinkyung,Jin, Youngyun,Kang, Hyunsik Japan Epidemiological Association 2018 Journal of epidemiology Vol.28 No.6

<P><B>Background</B></P><P>This study aimed to explore the associations between weight status, physical activity, and depression in Korean older adults.</P><P><B>Methods</B></P><P>We used the baseline data drawn from the 2008 baseline survey utilized in the Living Profiles of Older People Survey, comprised of 15,146 community-dwelling older people (42.6% men and 57.4% women) aged 60 years and older residing in the Republic of Korea. After excluding respondents with missing data on height, weight, and physical activity (PA), data on 10,197 samples (43.3% men and 56.7% women) were analyzed in this study.</P><P><B>Results</B></P><P>Underweight and completely inactive individuals had poorer sociodemographic and health behavioral characteristics and increased risks of late-life depression compared with normal weight and sufficiently active individuals, respectively. In terms of the aerobic PA guidelines, completely inactive individuals had a significantly higher risk of late-life depression (odds ratio 1.730; 95% confidence interval, 1.412–2.120) compared with sufficiently active individuals, even after adjustments for age, education, household income, night sleeping, living status, marital status, smoking, number of comorbidities, nutritional status, self-reported health status, and cognitive performance as covariates. In addition, those who did not meet the PA guidelines and were underweight or overweight/obese were more likely to have late-life depression compared to those who were active and normal weight.</P><P><B>Conclusions</B></P><P>The current findings of the study suggest that modifiable, lifestyle risk factors, such as physical inactivity, underweight, and overweight/obesity, are positively associated with late-life depression in Korean older adults.</P>

ACTN3 Gene and Susceptibility to Sarcopenia and Osteoporotic Status in Older Korean Adults

Cho, Jinkyung,Lee, Inhwan,Kang, Hyunsik Hindawi 2017 BioMed research international Vol.2017 No.-

<P><B>Background</B></P><P> Little information is available about molecular markers for sarcopenia and osteoporosis in Asian populations.</P><P><B> Objective</B></P><P> This study investigated the association of the<I> ACTN3</I> polymorphism with sarcopenia and osteoporotic status in older Korean adults.</P><P><B> Methods</B></P><P> Older Korean 62 men and 270 women (mean age 73.7 ± 6.6 years) participated in this study. Body mass index, percent body fatness, appendicular skeletal muscle mass, and bone mineral density of the lumbar spine, femur, and total body were analyzed with dual-energy X-ray absorptiometry.<I> ACTN3</I> R/X genotyping was determined using TaqMan probes.</P><P><B> Results</B></P><P> Determination of odds ratios (ORs) and 95% confidence intervals (CIs) using binary logistic regression analyses showed that XX homozygotes were at a significantly higher risk of sarcopenia (OR = 2.056, 95% CI = 1.024–4.127, <I>p</I> = 0.043) and osteoporosis (OR = 2.794, 95% CI = 1.208–5.461, <I>p</I> = 0.016) than RR homozygotes (reference group, OR = 1). The OR of XX homozygotes for having sarcopenia remained significant (OR = 2.237, 95% CI = 1.044–4.836, <I>p</I> = 0.038) after adjustments for age, gender, body fatness, and serum vitamin D. The OR of XX homozygotes for having osteoporosis was no longer significant (OR = 2.682, 95% CI = 0.960–7.942, <I>p</I> = 0.075) after adjustments for the covariates.</P><P><B> Conclusion</B></P><P> Our findings suggest that the<I> ACTN3</I> R577X genotype may influence decline in muscle and bone health phenotypes in older Korean adults.</P>

Treadmill Running Reverses Cognitive Declines due to Alzheimer Disease

CHO, JINKYUNG,SHIN, MIN-KYOO,KIM, DONGHYUN,LEE, INHWAN,KIM, SHINUK,KANG, HYUNSIK American College of Sports Medicine 2015 Medicine and science in sports and exercise Vol.47 No.9

PURPOSE: This study investigated the effect of treadmill running on cognitive declines in the early and advanced stages of Alzheimer disease (AD) in 3xTg-AD mice. METHODS: At 4 months of age, 3xTg-AD mice (N = 24) were assigned to control (AD + CON, n = 12) or exercise (AD + EX, n = 12) group. At 24 months of age, 3xTg-AD mice (N = 16) were assigned to AD + CON (n = 8) or AD + EX (n = 8) group. The AD + EX mice were subjected to treadmill running for 12 wk. At each pathological stage, the background strain mice were included as wild-type control (WT + CON, n = 8–12). RESULTS: At the early stage of AD, 3xTg-AD mice had impaired short- and long-term memory based on Morris water maze along with higher cortical A&bgr; deposition, higher hippocampal and cortical tau pathology, and lower hippocampal and cortical PSD-95 and synaptophysin. A 12-wk treadmill running reversed the impaired cognitive declines and significantly improved the tau pathology along with suppression of the decreased PSD-95 and synaptophysin in the hippocampus and cortex. At the advanced stage of AD, 3xTg-AD mice had impaired short- and long-term memory along with higher levels of A&bgr; deposition, soluble A&bgr;1–40 and A&bgr;1–42, tau pathology, and lower levels of brain-derived neurotrophic factor, PSD-95, and synaptophysin in the hippocampus and cortex. A 12-wk treadmill running reversed the impaired cognitive declines and significantly improved the A&bgr; and tau pathology along with suppression of the decreased synaptic proteins and brain-derived neurotrophic factor in the hippocampus and cortex. CONCLUSIONS: The current findings suggest that treadmill running provides a nonpharmacological means to combat cognitive declines due to AD pathology.

Effects of Water-loading Weight Loss on the Physiological Response in College Wrestlers

( Jinkyung Cho ),( Taekyung Han ) 한국운동생리학회(구 한국운동과학회) 2020 운동과학 Vol.29 No.3

PURPOSE: The purpose of this study was to evaluate the effects of water-loading weight loss on physiologic response. METHODS: Thirteen consenting university wrestlers (weight 71.5±8.0 kg, BMI 25.0±2.0 kg/m²) randomly divided into the weight loss (WL) group (n=6) and water-loading weight loss (WWL) group (n=7). Wrestlers performed 2-week weight loss program targeting average of 5-10% of body weight reduction, under the supervision of a coach. Participants were instructed to drink 1.5-2 L and 6-7 L daily during the first week in the WL and WWL groups, respectively. Both groups were gradually reduced water intake and didn’t drink water the day before weighing. Anthropometric characteristics, hematocrit (HCT), serum electrolytes, aldosterone, and cortisol were measured before and after weight loss. Data were analyzed with two-way ANOVA using SPSS. The significance level was set at p<.05. RESULTS: After 2 weeks, the weight (p=.004), BMI (p<.001), lean body mass (p<.001), body water composition (p<.001), and SBP (p=.046) were reduced significantly in both groups. However, there was no statistically significant between-group difference in all parameters of body composition and SBP. The HCT and chloride (Cl-) decreased in both WL and WWL groups (p=.018 and p=.006, respectively). Serum aldosterone and cortisol significantly increased in both groups (p<.001). In particular, cortisol was significantly lower in the WWL than in WL group. CONCLUSIONS: This study suggested that a large-volume hydration before water restriction for weight loss can be a safe method.

Consideration on Error Correction for Teaching Writing in EFL Class

( Jinkyung Cho ) 한국중등영어교육학회 2010 중등영어교육 Vol.3 No.1

For both communication and academic needs, the demand on teaching/learning writing in English is increasing in Korea as an EFL situation. In teaching/learning L2 writing, error correction should be one of the biggest considerations. On grammar correction in teaching L2 writing, there are pros and cons among researchers such as Truscott(1996), Ferris(1999) and many others. However, in teaching/learning writing in Korea, error correction is much needed withthe following reasons. First of all, students whose writing were corrected show more improvement in their writing than the others whose errors are not corrected. Second, error correction as a form of feedback helps L2students not to give up their endeavor in learning writing and makes them continue to write. In other words, giving feedback on their written errors seems to get better results. For successful error correction in teaching/learning L2 writing, having writing teachers well-trained and making our expectation more realistic should come first. Like asFerris(1999) insists, preparation, practice, and prioritizing of teachers in teaching L2 writing will be the answer to the practical problems. Also, co-teaching with well-prepared native writing teachers will be another alternative since we already have many native teachers in our English education field. Lastly strengthening selection criteria of hiring newEnglish teachers, focusing on their teaching ability of L2 writing, will be another answer.