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The effect of a short-term ketogenic diet on exercise efficiency during graded exercise in healthy adults.
Cho, W, Jung, H, Hong, S, Yang, HI, Park, DH, Suh, SH, Lee, DH, Choe, YS, Kim, JY, Lee, W, et al
Journal of the International Society of Sports Nutrition. 2023;(1):2264278
Abstract
OBJECTIVE We examined the effects of short-term KD on exercise efficiency and hormonal response during and after the graded exercise testing. METHODS Fourteen untrained healthy adults (8 males, 6 females, age 26.4 ± 3.1 [SD] years; BMI 24.8 ± 4.6 kg/m2; peak VO2max 54.0 ± 5.8 ml/kg FFM/min) completed 3-days of a mixed diet (MD) followed by another 3-days of KD after 3-days of washout period. Upon completion of each diet arm, participants underwent graded exercise testing with low- (LIE; 40% of VO2max), moderate- (MIE; 55%), and high-intensity exercise (HIE; 70%). Exercise efficiency was calculated as work done (kcal/min)/energy expenditure (kcal/min). RESULTS Fat oxidation during the recovery period was higher in KD vs. MD. Despite identical workload during HIE, participants after having KD vs. MD showed higher energy expenditure and lower exercise efficiency (10.1 ± 0.7 vs. 12.5 ± 0.3%, p < .01). After KD, free fatty acid (FFA) concentrations were higher during MIE and recovery vs. resting, and beta-hydroxybutylate (BOHB) was lower at HIE vs. resting. Cortisol concentrations after KD was higher during recovery vs. resting, with no significant changes during graded exercise testing after MD. CONCLUSIONS Our data suggest that short-term KD is favorable to fat metabolism leading increased circulating FFA and BOHB during LIE to MIE. However, it is notable that KD may cause 1) exercise inefficiency manifested by increased energy expenditure and 2) elevated exercise stress during HIE and recovery. Trial registration: KCT0005172, International Clinical Trials Registry Platform.
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Understanding Viral Infection Mechanisms and Patient Symptoms for the Development of COVID-19 Therapeutics.
Choi, HM, Moon, SY, Yang, HI, Kim, KS
International journal of molecular sciences. 2021;22(4)
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The outbreak of a novel coronavirus was reported in Wuhan, in the Hubei province of China, in December 2019. This virus was officially designated as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) because of its phylogenetic and taxonomic similarities to other coronaviruses. The aim of this review was to understand the viral infection mechanisms of SARS-CoV-2, the clinical features of Covid-19 and the mechanisms through which Covid-19 can be effectively treated with existing drugs. Literature shows that: • SARS-CoV-2 is usually transmitted by inhalation or contact with infected droplets. Inhaled droplets or aerosol carrying the virus then infect and spread through the respiratory tracts. • Severe inflammatory response is a remarkable feature of Covid-19 symptoms. This is caused by delayed viral clearance, which induces chronic systemic inflammation and widespread tissue damage, even leading to cytokine storms. • The incubation period is generally 5-6 days, but it ranges from one day to as much as two weeks. • Interstitial pneumonia and subsequent acute respiratory distress syndrome are the leading causes of death in patients with Covid-19. • There is no licensed treatment for Covid-19, only a combination of antiviral and anti-inflammatory drug treatments are being used. Authors conclude that their finding may provide new insights into the development of therapeutics by understanding the various clinical and basic research studies currently underway.
Abstract
Coronavirus disease 2019 (COVID-19), caused by the SARS-CoV-2 virus, has become a worldwide pandemic. Symptoms range from mild fever to cough, fatigue, severe pneumonia, acute respiratory distress syndrome (ARDS), and organ failure, with a mortality rate of 2.2%. However, there are no licensed drugs or definitive treatment strategies for patients with severe COVID-19. Only antiviral or anti-inflammatory drugs are used as symptomatic treatments based on clinician experience. Basic medical researchers are also trying to develop COVID-19 therapeutics. However, there is limited systematic information about the pathogenesis of COVID-19 symptoms that cause tissue damage or death and the mechanisms by which the virus infects and replicates in cells. Here, we introduce recent knowledge of time course changes in viral titers, delayed virus clearance, and persistent systemic inflammation in patients with severe COVID-19. Based on the concept of drug reposition, we review which antiviral or anti-inflammatory drugs can effectively treat COVID-19 patients based on progressive symptoms and the mechanisms inhibiting virus infection and replication.
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Dysregulated Autophagy Mediates Sarcopenic Obesity and Its Complications via AMPK and PGC1α Signaling Pathways: Potential Involvement of Gut Dysbiosis as a Pathological Link.
Ryu, JY, Choi, HM, Yang, HI, Kim, KS
International journal of molecular sciences. 2020;(18)
Abstract
Sarcopenic obesity (SOB), which is closely related to being elderly as a feature of aging, is recently gaining attention because it is associated with many other age-related diseases that present as altered intercellular communication, dysregulated nutrient sensing, and mitochondrial dysfunction. Along with insulin resistance and inflammation as the core pathogenesis of SOB, autophagy has recently gained attention as a significant mechanism of muscle aging in SOB. Known as important cellular metabolic regulators, the AMP-activated protein kinase (AMPK) and the peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α) signaling pathways play an important role in autophagy, inflammation, and insulin resistance, as well as mutual communication between skeletal muscle, adipose tissue, and the liver. Furthermore, AMPK and PGC-1α signaling pathways are implicated in the gut microbiome-muscle axis. In this review, we describe the pathological link between SOB and its associated complications such as metabolic, cardiovascular, and liver disease, falls and fractures, osteoarthritis, pulmonary disease, and mental health via dysregulated autophagy controlled by AMPK and/or PGC-1α signaling pathways. Here, we propose potential treatments for SOB by modulating autophagy activity and gut dysbiosis based on plausible pathological links.
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Effects of alternate day calorie restriction and exercise on cardio-metabolic risk factors in overweight and obese adults: an exploratory randomized controlled study.
Oh, M, Kim, S, An, KY, Min, J, Yang, HI, Lee, J, Lee, MK, Kim, DI, Lee, HS, Lee, JW, et al
BMC public health. 2018;(1):1124
Abstract
BACKGROUND It has been recognized that alternate day calorie restriction (ADCR) or exercise has positive effects on cardio-metabolic risk factors. It is unclear whether the combined effect of ADCR and exercise (aerobic + resistance training) influences risk. We investigated effects of an 8-week ADCR and exercise program (aerobic + resistance training) on cardio-metabolic risk factors in overweight and obese adults. METHODS This study randomized 45 overweight or obese but healthy adults (F = 26, M = 19; aged about 32 to 40 years) into 4 groups: ADCR (n = 13), exercise (n = 10), exercise plus ADCR (n = 12), and control (n = 10) for 8 weeks. Body composition, blood lipids profile, and insulin resistance were measured. The intention to treat (ITT) method was used to analyze all participants that were randomized. RESULTS A total of 35 participants completed the trial (78%). Body weight, body mass index, waist circumference, fat mass and percent body fat were reduced in the exercise plus ADCR group (- 3.3 ± 2.4 kg, p < 0.01; - 1.3 ± 1.0 kg/m2, p < 0.01; - 4.1 ± 3.9 cm, p < 0.01; - 2.7 ± 2.0 kg, p < 0.01; - 2. 5 ± 2.2%, p < 0.01). Insulin, glucose, homeostasis model assessment insulin resistance and triglyceride (- 2.9 ± 4.1 μIU/ml, p < 0.05; - 10.9 ± 16.9 mg/dl, p < 0.05; - 0.9 ± 1.3, p < 0.05; - 43.8 ± 41.9 mg/dl, p < 0.01) decreased in the exercise plus ADCR group only. CONCLUSIONS ADCR and exercise both proved to be beneficial, but the combined intervention was most effective at inducing beneficial changes in body weight, body composition, glucose, insulin, insulin resistance and triglyceride in overweight and obese adults. TRIAL REGISTRATION ClinicalTrials.gov: NCT03652532 , Registered August 28, 2018, 'retrospectively registered'.