DNA methylation of exercise-responsive genes differs between trained and untrained men.

BACKGROUND: Physical activity is well known for its multiple health benefits and although the knowledge of the underlying molecular mechanisms is increasing, our understanding of the role of epigenetics in long-term training adaptation remains incomplete. In this intervention study, we included individuals with a history of > 15 years of regular endurance or resistance training compared to age-matched untrained controls performing endurance or resistance exercise. We examined skeletal muscle DNA methylation of genes involved in key adaptation processes, including myogenesis, gene regulation, angiogenesis and metabolism. RESULTS: A greater number of differentially methylated regions and differentially expressed genes were identified when comparing the endurance group with the control group than in the comparison between the strength group and the control group at baseline. Although the cellular composition of skeletal muscle samples was generally consistent across groups, variations were observed in the distribution of muscle fiber types. Slow-twitch fiber type genes MYH7 and MYL3 exhibited lower promoter methylation and elevated expression in endurance-trained athletes, while the same group showed higher methylation in transcription factors such as FOXO3, CREB5, and PGC-1α. The baseline DNA methylation state of those genes was associated with the transcriptional response to an acute bout of exercise. Acute exercise altered very few of the investigated CpG sites. CONCLUSIONS: Endurance- compared to resistance-trained athletes and untrained individuals demonstrated a different DNA methylation signature of selected skeletal muscle genes, which may influence transcriptional dynamics following a bout of acute exercise. Skeletal muscle fiber type distribution is associated with methylation of fiber type specific genes. Our results suggest that the baseline DNA methylation landscape in skeletal muscle influences the transcription of regulatory genes in response to an acute exercise bout.

Muscle memory in humans: evidence for myonuclear permanence and long-term transcriptional regulation after strength training.

The objective of this work was to investigate myonuclear permanence and transcriptional regulation as mechanisms for cellular muscle memory after strength training in humans. Twelve untrained men and women performed 10 weeks of unilateral elbow-flexor strength training followed by 16 weeks of de-training. Thereafter, 10 weeks' re-training was conducted with both arms: the previously trained arm and the contralateral untrained control arm. Muscle biopsies were taken from the trained arm before and after both training periods and from the control arm before and after re-training. Muscle biopsies were analysed for fibre cross-sectional area (fCSA), myonuclei and global transcriptomics (RNA sequencing). During the first training period, myonuclei increased in type 1 (13 ± 17%) and type 2 (33 ± 23%) fibres together with a 30 ± 43% non-significant increase in mixed fibre fCSA (P = 0.069). Following de-training, fCSA decreased in both fibre types, whereas myonuclei were maintained, resulting in 33% higher myonuclear number in previously trained vs. control muscle in type 2 fibres. Furthermore, in the previously trained muscle, three differentially expressed genes (DEGs; EGR1, MYL5 and COL1A1) were observed. Following re-training, the previously trained muscle showed larger type 2 fCSA compared to the control (P = 0.035). However, delta change in type 2 fCSA was not different between muscles. Gene expression was more dramatically changed in the control arm (1338 DEGs) than in the previously trained arm (822 DEGs). The sustained higher number of myonuclei in the previously trained muscle confirms myonuclear accretion and permanence in humans. Nevertheless, because of the unclear effect on the subsequent hypertrophy with re-training, the physiological benefit remains to be determined. KEY POINTS: Muscle memory is a cellular mechanism that describes the capacity of skeletal muscle fibres to respond differently to training stimuli if the stimuli have been previously encountered. This study overcomes past methodological limitations related to the choice of muscles and analytical procedures. We show that myonuclear number is increased after strength training and maintained during de-training. Increased myonuclear number and differentially expressed genes related to muscle performance and development in the previously trained muscle did not translate into a clearly superior responses during re-training. Because of the unclear effect on the subsequent hypertrophy and muscle strength gain with re-training, the physiological benefit remains to be determined.

Building resilience: analysis of health care leaders' perspectives on the Covid-19 response in Region Stockholm.

BACKGROUND: The Covid-19 pandemic has tested health care organizations worldwide. Responses have demonstrated great variation and Sweden has been an outlier in terms of both strategy and how it was enacted, making it an interesting case for further study. The aim of this study was to explore how health care leaders experienced the challenges and responses that emerged during the initial wave of the Covid-19 pandemic, and to analyze these experiences through an organizational resilience lens. METHODS: A qualitative interview study with 12 senior staff members who worked directly with or supervised pandemic efforts. Transcripts were analyzed using traditional content analysis and the codes directed to the Integrated Resilience Attributes Framework to understand what contributed to or hindered organizational resilience, i.e. how organizations achieve their goals by utilizing existing resources during crises. RESULTS/FINDINGS: Organizational resilience was found at the micro (situated) and meso (structural) system levels as individuals and organizations dealt with acute shortages and were forced to rapidly adapt through individual sacrifices, resource management, process management, and communications and relational capacity. Poor systemic resilience related to misaligned responses and a lack of learning from previous experiences, negatively impacted the anticipatory phase and placed greater pressure on individuals and organizations to respond. Conventional crisis leadership could hamper innovation, further cement chronic challenges, and generate a moral tension between centralized directives and clinical microsystem experiences. CONCLUSIONS: The pandemic tested the resilience of the health care system, placing undue pressure on micro and meso systems responses. With improved learning capabilities, some of this pressure may be mitigated as it could raise the anticipatory resilience potential, i.e. with better health systems learning, we may need fewer heroes. How crisis leadership could better align decision-making with frontline needs and temper short-term acute needs with a longer-term infinite mindset is worth further study.

Positive Effects of Physical Activity on Prescription on Glycemic Control, Fitness, and Quality of Life in Newly Diagnosed Type 2 Diabetic Patients.

The aim was to investigate the effects of physical activity on prescription (PAP) compared with standard care (SC) in adult drug-naïve T2D patients. A randomized control trial was conducted with drug-naïve T2D patients attending an out-patient clinic Vietnam. Participants were randomly assigned to the PAP group (n+=+44) or the SC group (n+=+43). The PAP group received individualized recommendations for PA, intensive face-to-face training every two weeks. The SC group received the standard recommendations according to WHO guidelines. The mean HbA1c level change was larger (-10.6±6.4 mmol/mol) in the PAP group than in the SC group (-2.4±5.8 mmol/mol) (p<0.001). A one thousand step counts per day increase was significantly associated with a decrease of -2.43 mmol/mol in HbA1c [ß=-2.43, 95%CI: (-2.94, -1.92]) in the PAP group. The fasting plasma glucose levels of the PAP group decreased significantly compared with the SC group. The VO2-max increased significantly more in the PAP group than in the SC group. PAP had clear positive effects on health-related Quality of Life [mean between group difference: 9.54 (95%CI 5.84,13.23)]. Insulin resistance, BMI, waist circumference, total cholesterol, LDL cholesterol and triglycerides were significantly more decreased in the PAP group than in the control group. In conclusion, the fact that even a small change in mean step counts over three months had a beneficial effect on health-related outcomes in drug-naïve T2D patients can have large implications for treatment and management practices, not least in a middle-income country like Vietnam.

Mobile health to promote physical activity in people post stroke or transient ischemic attack - study protocol for a feasibility randomised controlled trial.

BACKGROUND: Physical activity is essential to improve health and reduce the risk of recurrence of stroke or transient ischemic attack (TIA). Still, people post stroke or TIA are often physically inactive and the availability of physical activity promotion services are often limited. This study builds on an existing Australian telehealth-delivered programme (i-REBOUND- Let's get moving) which provides support for home-based physical activity for people post stroke or TIA. The aim of this study is to test the feasibility, acceptability, and preliminary effects of a mobile Health (mHealth) version of the i-REBOUND programme for the promotion of physical activity in people post stroke or TIA living in Sweden. METHODS: One hundred and twenty participants with stroke or TIA will be recruited via advertisement. A parallel-group feasibility randomised controlled trial design with a 1:1 allocation ratio to 1) i-REBOUND programme receiving physical exercise and support for sustained engagement in physical activity through behavioural change techniques, or 2) behavioural change techniques for physical activity. Both interventions will proceed for six months and be delivered digitally through a mobile app. The feasibility outcomes (i.e., reach, adherence, safety and fidelity) will be monitored throughout the study. Acceptability will be assessed using the Telehealth Usability Questionnaire and further explored through qualitative interviews with a subset of both study participants and the physiotherapists delivering the intervention. Clinical outcomes on preliminary effects of the intervention will include blood pressure, engagement in physical activity, self-perceived exercise self-efficacy, fatigue, depression, anxiety, stress and health-related quality of life and will be measured at baseline and at 3, 6 and 12 months after the baseline assessments. DISCUSSION: We hypothesise that the mHealth delivery of the i-REBOUND programme will be feasible and acceptable in people post stroke/TIA living in rural and urban regions of Sweden. The results of this feasibility trial will inform the development of full-scale and appropriately powered trial to test the effects and costs of mHealth delivered physical activity for people after stroke or TIA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05111951. Registered November 8, 2021.

Introducing Braining-physical exercise as adjunctive therapy in psychiatric care: a retrospective cohort study of a new method.

BACKGROUND: Patients with severe mental disorders suffer from higher rates of poor somatic health and have shorter life expectancy than the average population. Physical activity can treat and prevent several diseases, e.g. cardiovascular and metabolic disorders as well as psychiatric symptoms. It is therefore of utmost importance to develop effective methods to integrate physical activity into psychiatric care. To meet this need, the physical activity intervention Braining was developed. This study aims to describe Braining, to assess the number of patients reached during the first years of pilot testing, to analyze clinical data in the group of patients participating in Braining 2017-2020 and to assess the intervention. METHODS: In this descriptive retrospective study we analyzed data from all patients participating in Braining training sessions ≥ 3 times (n = 239), the Braining Participants. Regular patients at the clinic served as a comparison. Furthermore, medical records were studied for a smaller cohort (n = 51), the Braining Pilot Cohort. Data was analyzed using Chi-square and Fisher's tests. RESULTS: During the introduction period of Braining, 580 patients attended an information meeting about Braining, or at least one training session. 239 patients participated in ≥ 3 training sessions, considered to be participants of Braining. These Braining Participants (n = 239), ages 19 to 82, males 23.4%, attended between 3 and 308 training sessions (median 9). The main diagnoses were affective and anxiety disorders. Number of diagnoses ranged from 0 to 10 (median = 2). For the subsample, the Braining Pilot Cohort (n = 51), participants attended between 3 and 208 training sessions (median = 20). Twelve percent were working full-time, and symptom severity of depression and general anxiety was moderate. Two thirds had ≥ 3 different classes of medication. Regarding metabolic morbidity, 28 had been diagnosed with hypertension, though blood lipids, blood glucose as well as blood pressure were within the normal range. Thirty-seven percent were prescribed Physical Activity on Prescription during 2017-2020. One severe adverse event was reported. CONCLUSIONS: The Braining intervention reached all age-groups and patients with a wide and representative diagnostic panorama, suggesting that Braining could be a promising and safe method for implementing physical activity in a psychiatric patient population.

Use of Self-Reported Computerized Medical History Taking for Acute Chest Pain in the Emergency Department - the Clinical Expert Operating System Chest Pain Danderyd Study (CLEOS-CPDS): Prospective Cohort Study.

BACKGROUND: Chest pain is one of the most common chief complaints in emergency departments (EDs). Collecting an adequate medical history is challenging but essential in order to use recommended risk scores such as the HEART score (based on history, electrocardiogram, age, risk factors, and troponin). Self-reported computerized history taking (CHT) is a novel method to collect structured medical history data directly from the patient through a digital device. CHT is rarely used in clinical practice, and there is a lack of evidence for utility in an acute setting. OBJECTIVE: This substudy of the Clinical Expert Operating System Chest Pain Danderyd Study (CLEOS-CPDS) aimed to evaluate whether patients with acute chest pain can interact effectively with CHT in the ED. METHODS: Prospective cohort study on self-reported medical histories collected from acute chest pain patients using a CHT program on a tablet. Clinically stable patients aged 18 years and older with a chief complaint of chest pain, fluency in Swedish, and a nondiagnostic electrocardiogram or serum markers for acute coronary syndrome were eligible for inclusion. Patients unable to carry out an interview with CHT (eg, inadequate eyesight, confusion or agitation) were excluded. Effectiveness was assessed as the proportion of patients completing the interview and the time required in order to collect a medical history sufficient for cardiovascular risk stratification according to HEART score. RESULTS: During 2017-2018, 500 participants were consecutively enrolled. The age and sex distribution (mean 54.3, SD 17.0 years; 213/500, 42.6% women) was similar to that of the general chest pain population (mean 57.5, SD 19.2 years; 49.6% women). Common reasons for noninclusion were language issues (182/1000, 18.2%), fatigue (158/1000, 15.8%), and inability to use a tablet (152/1000, 15.2%). Sufficient data to calculate HEART score were collected in 70.4% (352/500) of the patients. Key modules for chief complaint, cardiovascular history, and respiratory history were completed by 408 (81.6%), 339 (67.8%), and 291 (58.2%) of the 500 participants, respectively, while 148 (29.6%) completed the entire interview (in all 14 modules). Factors associated with completeness were age 18-69 years (all key modules: Ps<.001), male sex (cardiovascular: P=.04), active workers (all key modules: Ps<.005), not arriving by ambulance (chief complaint: P=.03; cardiovascular: P=.045), and ongoing chest pain (complete interview: P=.002). The median time to collect HEART score data was 23 (IQR 18-31) minutes and to complete an interview was 64 (IQR 53-77) minutes. The main reasons for discontinuing the interview prior to completion (n=352) were discharge from the ED (101, 28.7%) and tiredness (95, 27.0%). CONCLUSIONS: A majority of patients with acute chest pain can interact effectively with CHT on a tablet in the ED to provide sufficient data for risk stratification with a well-established risk score. The utility was somewhat lower in patients 70 years and older, in patients arriving by ambulance, and in patients without ongoing chest pain. Further studies are warranted to assess whether CHT can contribute to improved management and prognosis in this large patient group. TRIAL REGISTRATION: ClinicalTrials.gov NCT03439449; https://clinicaltrials.gov/ct2/show/NCT03439449. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2019-031871.

Exercise training during chemotherapy preserves skeletal muscle fiber area, capillarization, and mitochondrial content in patients with breast cancer.

Exercise has been suggested to ameliorate the detrimental effects of chemotherapy on skeletal muscle. The aim of this study was to compare the effects of different exercise regimens with usual care on skeletal muscle morphology and mitochondrial markers in patients being treated with chemotherapy for breast cancer. Specifically, we compared moderate-intensity aerobic training combined with high-intensity interval training (AT-HIIT) and resistance training combined with high-intensity interval training (RT-HIIT) with usual care (UC). Resting skeletal muscle biopsies were obtained pre- and postintervention from 23 randomly selected women from the OptiTrain breast cancer trial who underwent RT-HIIT, AT-HIIT, or UC for 16 wk. Over the intervention, citrate synthase activity, muscle fiber cross-sectional area, capillaries per fiber, and myosin heavy chain isoform type I were reduced in UC, whereas RT-HIIT and AT-HIIT were able to counteract these declines. AT-HIIT promoted up-regulation of the electron transport chain protein levels vs. UC. RT-HIIT favored satellite cell count vs. UC and AT-HIIT. There was a significant association between change in citrate synthase activity and self-reported fatigue. AT-HIIT and RT-HIIT maintained or improved markers of skeletal muscle function compared with the declines found in the UC group, indicating a sustained trainability in addition to the preservation of skeletal muscle structural and metabolic characteristics during chemotherapy. These findings highlight the importance of supervised exercise programs for patients with breast cancer during chemotherapy.-Mijwel, S., Cardinale, D. A., Norrbom, J., Chapman, M., Ivarsson, N., Wengström, Y., Sundberg, C. J., Rundqvist, H. Exercise training during chemotherapy preserves skeletal muscle fiber area, capillarization, and mitochondrial content in patients with breast cancer.

The Impact of Endurance Training on Human Skeletal Muscle Memory, Global Isoform Expression and Novel Transcripts.

Regularly performed endurance training has many beneficial effects on health and skeletal muscle function, and can be used to prevent and treat common diseases e.g. cardiovascular disease, type II diabetes and obesity. The molecular adaptation mechanisms regulating these effects are incompletely understood. To date, global transcriptome changes in skeletal muscles have been studied at the gene level only. Therefore, global isoform expression changes following exercise training in humans are unknown. Also, the effects of repeated interventions on transcriptional memory or training response have not been studied before. In this study, 23 individuals trained one leg for three months. Nine months later, 12 of the same subjects trained both legs in a second training period. Skeletal muscle biopsies were obtained from both legs before and after both training periods. RNA sequencing analysis of all 119 skeletal muscle biopsies showed that training altered the expression of 3,404 gene isoforms, mainly associated with oxidative ATP production. Fifty-four genes had isoforms that changed in opposite directions. Training altered expression of 34 novel transcripts, all with protein-coding potential. After nine months of detraining, no training-induced transcriptome differences were detected between the previously trained and untrained legs. Although there were several differences in the physiological and transcriptional responses to repeated training, no coherent evidence of an endurance training induced transcriptional skeletal muscle memory was found. This human lifestyle intervention induced differential expression of thousands of isoforms and several transcripts from unannotated regions of the genome. It is likely that the observed isoform expression changes reflect adaptational mechanisms and processes that provide the functional and health benefits of regular physical activity.

Adding high-intensity interval training to conventional training modalities: optimizing health-related outcomes during chemotherapy for breast cancer: the OptiTrain randomized controlled trial.

PURPOSE: Exercise training is an effective and safe way to counteract cancer-related fatigue (CRF) and to improve health-related quality of life (HRQoL). High-intensity interval training has proven beneficial for the health of clinical populations. The aim of this randomized controlled trial was to compare the effects of resistance and high-intensity interval training (RT-HIIT), and moderate-intensity aerobic and high-intensity interval training (AT-HIIT) to usual care (UC) in women with breast cancer undergoing chemotherapy. The primary endpoint was CRF and the secondary endpoints were HRQoL and cancer treatment-related symptoms. METHODS: Two hundred and forty women planned to undergo chemotherapy were randomized to supervised RT-HIIT, AT-HIIT, or UC. Measurements were performed at baseline and at 16 weeks. Questionnaires included Piper Fatigue Scale, EORTC-QLQ-C30, and Memorial Symptom Assessment Scale. RESULTS: The RT-HIIT group was superior to UC for CRF: total CRF (p = 0.02), behavior/daily life (p = 0.01), and sensory/physical (p = 0.03) CRF. Role functioning significantly improved while cognitive functioning was unchanged for RT-HIIT compared to declines shown in the UC group (p = 0.04). AT-HIIT significantly improved emotional functioning versus UC (p = 0.01) and was superior to UC for pain symptoms (p = 0.03). RT-HIIT reported a reduced symptom burden, while AT-HIIT remained stable compared to deteriorations shown by UC (p < 0.01). Only RT-HIIT was superior to UC for total symptoms (p < 0.01). CONCLUSIONS: 16 weeks of resistance and HIIT was effective in preventing increases in CRF and in reducing symptom burden for patients during chemotherapy for breast cancer. These findings add to a growing body of evidence supporting the inclusion of structured exercise prescriptions, including HIIT, as a vital component of cancer rehabilitation. TRIAL REGISTRATION: Clinicaltrials.gov Registration Number: NCT02522260.

Highly favorable physiological responses to concurrent resistance and high-intensity interval training during chemotherapy: the OptiTrain breast cancer trial.

BACKGROUND: Advanced therapeutic strategies are often accompanied by significant adverse effects, which warrant equally progressive countermeasures. Physical exercise has proven an effective intervention to improve physical function and reduce fatigue in patients undergoing chemotherapy. Effects of high-intensity interval training (HIIT) in this population are not well established although HIIT has proven effective in other clinical populations. The aim of the OptiTrain trial was to examine the effects of concurrent resistance and high-intensity interval training (RT-HIIT) or concurrent moderate-intensity aerobic and high-intensity interval training (AT-HIIT), to usual care (UC) on pain sensitivity and physiological outcomes in patients with breast cancer during chemotherapy. METHODS: Two hundred and forty women were randomized to 16 weeks of RT-HIIT, AT-HIIT, or UC. OUTCOMES: cardiorespiratory fitness, muscle strength, body mass, hemoglobin levels, and pressure-pain threshold. RESULTS: Pre- to post-intervention, RT-HIIT (ES = 0.41) and AT-HIIT (ES = 0.42) prevented the reduced cardiorespiratory fitness found with UC. Handgrip strength (surgery side: RT-HIIT vs. UC: ES = 0.41, RT-HIIT vs. AT-HIIT: ES = 0.28; non-surgery side: RT-HIIT vs. UC: ES = 0.35, RT-HIIT vs. AT-HIIT: ES = 0.22) and lower-limb muscle strength (RT-HIIT vs. UC: ES = 0.66, RT-HIIT vs. AT-HIIT: ES = 0.23) were significantly improved in the RT-HIIT. Increases in body mass were smaller in RT-HIIT (ES = - 0.16) and AT-HIIT (ES = - 0.16) versus UC. RT-HIIT reported higher pressure-pain thresholds than UC (trapezius: ES = 0.46, gluteus: ES = 0.53) and AT-HIIT (trapezius: ES = 0.30). CONCLUSION: Sixteen weeks of RT-HIIT significantly improved muscle strength and reduced pain sensitivity. Both exercise programs were well tolerated and were equally efficient in preventing increases in body mass and in preventing declines in cardiorespiratory fitness. These results highlight the importance of implementing a combination of resistance and high-intensity interval training during chemotherapy for women with breast cancer.

Exercise in type 2 diabetes: genetic, metabolic and neuromuscular adaptations. A review of the evidence.

The biological responses to exercise training are complex, as almost all organs and systems are involved in interactions that result in a plethora of adaptations at the genetic, metabolic and neuromuscular levels.To provide the general practitioner and the sports medicine professionals with a basic understanding of the genetic, metabolic and neuromuscular adaptations at a cellular level that occur with aerobic and resistance exercise in subjects with type 2 diabetes.For each of the three domains (genetic, metabolic and neuromuscular), the results of the major systematic reviews and original research published in relevant journals, indexed in PubMed, were selected. Owing to limitations of space, we focused primarily on the role of skeletal muscle, given its pivotal role in mediating adaptations at all levels.Generally, training-induced adaptations in skeletal muscle are seen as changes in contractile proteins, mitochondrial function, metabolic regulation, intracellular signalling, transcriptional responses and neuromuscular modifications. The main adaptation with clinical relevance would include an improved oxidative capacity derived from aerobic training, in addition to neuromuscular remodelling derived from resistance training. Both training modalities improve insulin sensitivity and reduce cardiovascular risk.Taken together, the modifications that occur at the genetic, metabolic and neuromuscular levels, work correlatively to optimise substrate delivery, mitochondrial respiratory capacity and contractile function during exercise.

The human cardiac and skeletal muscle proteomes defined by transcriptomics and antibody-based profiling.

BACKGROUND: To understand cardiac and skeletal muscle function, it is important to define and explore their molecular constituents and also to identify similarities and differences in the gene expression in these two different striated muscle tissues. Here, we have investigated the genes and proteins with elevated expression in cardiac and skeletal muscle in relation to all other major human tissues and organs using a global transcriptomics analysis complemented with antibody-based profiling to localize the corresponding proteins on a single cell level. RESULTS: Our study identified a comprehensive list of genes expressed in cardiac and skeletal muscle. The genes with elevated expression were further stratified according to their global expression pattern across the human body as well as their precise localization in the muscle tissues. The functions of the proteins encoded by the elevated genes are well in line with the physiological functions of cardiac and skeletal muscle, such as contraction, ion transport, regulation of membrane potential and actomyosin structure organization. A large fraction of the transcripts in both cardiac and skeletal muscle correspond to mitochondrial proteins involved in energy metabolism, which demonstrates the extreme specialization of these muscle tissues to provide energy for contraction. CONCLUSIONS: Our results provide a comprehensive list of genes and proteins elevated in striated muscles. A number of proteins not previously characterized in cardiac and skeletal muscle were identified and localized to specific cellular subcompartments. These proteins represent an interesting starting point for further functional analysis of their role in muscle biology and disease.

Levels of circulating angiotensin-converting enzyme 2 are affected by acute exercise and correlate with markers of physical fitness in male athletes.

While under physiological conditions angiotensin-converting enzyme 2 (ACE2) is an antagonist of vasoconstrictive agents in the renin-angiotensin-aldosterone system (RAAS), in the context of SARS coronavirus 2 (SARS-CoV-2) ACE2 serves as the gateway into cells. Furthermore, RAAS has previously been shown to be influenced by exercise training and is suggested to be involved in skeletal muscle mass maintenance. Given this connection, the investigation of circulating ACE2 plasma protein concentration before and following acute and chronic endurance and resistance exercise could increase the understanding of the implications of the exposure of athletes to SARS-CoV-2. Therefore, this study investigated levels of circulating ACE2 in lifelong high-level trained endurance and resistance athletes and control subjects in response to either acute endurance or resistance exercise. Results show no baseline differences in absolute ACE2 concentration between groups, but a strong negative correlation with levels of fitness and positive correlation with BMI in control subjects. Furthermore, acute endurance exercise significantly increased ACE2 levels across all groups, but only in the strength group in response to resistance exercise. This indicates that circulating ACE2 plasma levels are influenced by levels of fitness and health, and that acute endurance exercise has a stronger effect on plasma ACE2 levels than resistance exercise.

Are medical history data fit for risk stratification of patients with chest pain in emergency care? Comparing data collected from patients using computerized history taking with data documented by physicians in the electronic health record in the CLEOS-CPDS prospective cohort study.

OBJECTIVE: In acute chest pain management, risk stratification tools, including medical history, are recommended. We compared the fraction of patients with sufficient clinical data obtained using computerized history taking software (CHT) versus physician-acquired medical history to calculate established risk scores and assessed the patient-by-patient agreement between these 2 ways of obtaining medical history information. MATERIALS AND METHODS: This was a prospective cohort study of clinically stable patients aged ≥ 18 years presenting to the emergency department (ED) at Danderyd University Hospital (Stockholm, Sweden) in 2017-2019 with acute chest pain and non-diagnostic ECG and serum markers. Medical histories were self-reported using CHT on a tablet. Observations on discrete variables in the risk scores were extracted from electronic health records (EHR) and the CHT database. The patient-by-patient agreement was described by Cohen's kappa statistics. RESULTS: Of the total 1000 patients included (mean age 55.3 ± 17.4 years; 54% women), HEART score, EDACS, and T-MACS could be calculated in 75%, 74%, and 83% by CHT and in 31%, 7%, and 25% by EHR, respectively. The agreement between CHT and EHR was slight to moderate (kappa 0.19-0.70) for chest pain characteristics and moderate to almost perfect (kappa 0.55-0.91) for risk factors. CONCLUSIONS: CHT can acquire and document data for chest pain risk stratification in most ED patients using established risk scores, achieving this goal for a substantially larger number of patients, as compared to EHR data. The agreement between CHT and physician-acquired history taking is high for traditional risk factors and lower for chest pain characteristics. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT03439449.

The effect of neuromuscular electrical stimulation on the human skeletal muscle transcriptome.

AIM: The influence on acute skeletal muscle transcriptomics of neuromuscular electrical stimulation (NMES), as compared to established exercises, is poorly understood. We aimed to investigate the effects on global mRNA-expression in the quadriceps muscle early after a single NMES-session, compared to the effects of voluntary knee extension exercise (EX), and to explore the discomfort level. METHODS: Global vastus lateralis muscle gene expression was assessed (RNA-sequencing) in 30 healthy participants, before and 3 h after a 30-min session of NMES and/or EX. The NMES-treatment was applied using textile electrodes integrated in pants and set to 20% of each participant's pre-tested MVC mean (±SD) 200 (±80) Nm. Discomfort was assessed using Visual Analogue Scale (VAS, 0-10). The EX-protocol was performed at 80% of 1-repetition-maximum. RESULTS: NMES at 20% of MVC resulted in VAS below 4 and induced 4448 differentially expressed genes (DEGs) with 80%-overlap of the 2571 DEGs of EX. Genes well-known to be up-regulated following exercise, for example, PPARGC1A, ABRA, VEGFA, and GDNF, were also up-regulated by NMES. Gene set enrichment analysis demonstrated many common pathways after EX and NMES. Also, some pathways were exclusive to either EX, for example, muscle tissue proliferation, or to NMES, for example, neurite outgrowth and connective tissue proliferation. CONCLUSION: A 30-min NMES-session at 20% of MVC with NMES-pants, which can be applied with an acceptable level of discomfort, induces over 4000 DEGs, of which 80%-overlap with DEGs of EX. NMES can induce exercise-like molecular effects, that potentially can lead to health and performance benefits in individuals who are unable to perform resistance exercise.

Molecular profiling of high-level athlete skeletal muscle after acute endurance or resistance exercise - A systems biology approach.

OBJECTIVE: Long-term high-level exercise training leads to improvements in physical performance and multi-tissue adaptation following changes in molecular pathways. While skeletal muscle baseline differences between exercise-trained and untrained individuals have been previously investigated, it remains unclear how training history influences human multi-omics responses to acute exercise. METHODS: We recruited and extensively characterized 24 individuals categorized as endurance athletes with >15 years of training history, strength athletes or control subjects. Timeseries skeletal muscle biopsies were taken from M. vastus lateralis at three time-points after endurance or resistance exercise was performed and multi-omics molecular analysis performed. RESULTS: Our analyses revealed distinct activation differences of molecular processes such as fatty- and amino acid metabolism and transcription factors such as HIF1A and the MYF-family. We show that endurance athletes have an increased abundance of carnitine-derivates while strength athletes increase specific phospholipid metabolites compared to control subjects. Additionally, for the first time, we show the metabolite sorbitol to be substantially increased with acute exercise. On transcriptional level, we show that acute resistance exercise stimulates more gene expression than acute endurance exercise. This follows a specific pattern, with endurance athletes uniquely down-regulating pathways related to mitochondria, translation and ribosomes. Finally, both forms of exercise training specialize in diverging transcriptional directions, differentiating themselves from the transcriptome of the untrained control group. CONCLUSIONS: We identify a "transcriptional specialization effect" by transcriptional narrowing and intensification, and molecular specialization effects on metabolomic level Additionally, we performed multi-omics network and cluster analysis, providing a novel resource of skeletal muscle transcriptomic and metabolomic profiling in highly trained and untrained individuals.

Remodeling of the human skeletal muscle proteome found after long-term endurance training but not after strength training.

Exercise training has tremendous systemic tissue-specific health benefits, but the molecular adaptations to long-term exercise training are not completely understood. We investigated the skeletal muscle proteome of highly endurance-trained, strength-trained, and untrained individuals and performed exercise- and sex-specific analyses. Of the 6,000+ proteins identified, >650 were differentially expressed in endurance-trained individuals compared with controls. Strikingly, 92% of the shared proteins with higher expression in both the male and female endurance groups were known mitochondrial. In contrast to the findings in endurance-trained individuals, minimal differences were found in strength-trained individuals and between females and males. Lastly, a co-expression network and comparative literature analysis revealed key proteins and pathways related to the health benefits of exercise, which were primarily related to differences in mitochondrial proteins. This network is available as an interactive database resource where investigators can correlate clinical data with global gene and protein expression data for hypothesis generation.

Impact of Menstrual cycle-based Periodized training on Aerobic performance, a Clinical Trial study protocol-the IMPACT study.

BACKGROUND: The menstrual cycle and its impact on training and performance are of growing interest. However, evidence is lacking whether periodized exercise based on the menstrual cycle is beneficial. The primary purpose of this proposed randomized, controlled trial, the IMPACT study, is to evaluate the effect of exercise periodization during different phases of the menstrual cycle, i.e., comparing follicular phase-based and luteal phase-based training with regular training during the menstrual cycle on physical performance in well-trained women. METHODS: Healthy, well-trained, eumenorrheic women between 18 and 35 years (n = 120) will be recruited and first assessed for physical performance during a run-in menstrual cycle at different cycle phases and then randomized to three different interventions: follicular phase-based training, luteal phase-based training, or regular training during three menstrual cycles. The training intervention will consist of high-intensity spinning classes followed by strength training. The menstrual cycle phases will be determined by serum hormone analysis throughout the intervention period. Assessment of aerobic performance (primary outcome) and muscle strength, body composition, and blood markers will be performed at baseline and at the end of the intervention. DISCUSSION: With a robust methodology, this study has the potential to provide evidence of the differential effects of exercise periodization during different phases of the menstrual cycle in female athletes. TRIAL REGISTRATION: ClinicalTrials.gov NCT05697263 . Registered on 25 January 2023.