Jørn W Helge

Jørn W Helge
University of Copenhagen · Department of Biomedical Sciences

PhD

About

274
Publications
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9,053
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January 1996 - December 2013
University of Copenhagen

Publications

Publications (274)
Article
Background Individual differences in the rate of aging and susceptibility to disease are not accounted for by chronological age alone. These individual differences are better explained by biological age, which may be estimated by biomarker prediction models. In the light of the aging demographics of the global population and the increase in lifesty...
Article
Introduction Elevated luteinizing hormone (LH) in combination with low-normal testosterone (mild Leydig cell insufficiency) is common in testicular cancer (TC) survivors and is associated with impaired insulin sensitivity and metabolic syndrome. The aim was to evaluate if testosterone replacement therapy (TRT) improves metabolic health in this subg...
Article
Maximal fat oxidation during exercise (MFO) and the intensity that elicits MFO (Fatmax) seems to show a diurnal variation in men, which favors an increased performance in the afternoon than the morning. At present, it remains unknown whether the observed MFO and Fatmax diurnal variation in men is also present in women. Therefore, the current study...
Article
Full-text available
Aim & methods: Extreme endurance exercise provides a valuable research model for understanding the adaptive metabolic response of older and younger individuals to intense physical activity. Here, we compare a wide range of metabolic and physiologic parameters in two cohorts of seven trained men, age 30±5 years or age 65±6 years, before and after t...
Preprint
BACKGROUND Individual differences in the rate of aging and susceptibility to disease are not accounted for by chronological age alone. These individual differences are better explained by biological age, which may be estimated by biomarker prediction models. In the light of the aging demographics of the global population and the increase in lifesty...
Article
Statins are prescribed for the treatment of elevated cholesterol, but they may negatively affect metabolism, muscle performance, and the response to training. Coenzyme Q10 (CoQ10) supplementation may alleviate these effects. Combined simvastatin and CoQ10 treatment during physical training has never been tested. We studied the response to 8 weeks t...
Article
Full-text available
The study aimed to determine the levels of skeletal muscle Angiotensin‐Converting Enzyme 2 (ACE2, the SARS‐CoV‐2 receptor) protein expression in men and women and assess whether ACE2 expression in skeletal muscle is associated with cardiorespiratory fitness and adiposity. The level of ACE2 in vastus lateralis muscle biopsies collected in previous s...
Article
Full-text available
Adipose tissue mitochondrial function is gaining increasing interest since it is good marker of overall health. Methodological challenges and variability in assessing mitochondrial respiration in fresh adipose tissue with high resolution respirometry are unknown and should be explored. Mitochondrial respiratory capacity (MRC) in human adipose tissu...
Poster
Introduction Low cardiorespiratory fitness expressed as a low maximal oxygen consumption (V̇O2max) is associated with cardiovascular disease and all-cause mortality (1). Thus, V̇O2max is recognised as an important clinical tool in the assessment of patients (1,2). However, assessment of V̇O2max by exercise testing is both physically demanding and m...
Article
Full-text available
PurposeLow bone mineral density (BMD) and fractures are a major concern in the female population and preventative strategies are needed. Whether team sports participation may reduce age-related bone loss in elderly women is still uncertain.Methods One hundred and thirty healthy, non-smoking women participated in this cross-sectional study, i.e., el...
Article
The aim was to investigate if acute recombinant human erythropoietin (rHuEPO) injection had an effect on mitochondrial function and if exercise would have an additive effect. Furthermore to investigate if in-vitro incubation with rHuEPO had an effect on muscle mitochondrial respiratory capacity. Eight healthy young men were recruited for this doubl...
Article
Objectives The agro-pastoralist Maasai of East Africa are highly physically active, but their aerobic fitness has so far only been estimated using heart rate (HR) response to submaximal exercise and not directly measured. Thus, we aimed to measure aerobic fitness directly using respiratory gas analysis in a group of Maasai, and habitual physical ac...
Article
Full-text available
Purpose To examine efficacy of 12 months Football Fitness offered twice per week on bone mineral density (BMD), bone turnover markers (BTM), postural balance, muscle strength and body composition in women treated for early‐stage breast cancer (BC). Methods Women treated for early‐stage BC were randomised to Football Fitness (FFG, n=46) or control...
Article
Obesity has been associated with increased production of reactive oxygen species (ROS), which may be involved in the development of cardiovascular disease and type 2 diabetes (T2D). Endurance exercise lowers ROS production and increases antioxidant capacity in muscle cells, but it is currently unknown whether high intensity interval training (HIT)...
Article
Introduction Maximal fat oxidation rate (MFO) is higher in aerobically fit vs. unfit young men, but this training related increase in MFO is attenuated in middle-aged men. Further, it has also been found that unfit men with obesity may have an elevated MFO compared to unfit normal-weight men. Aim/Hypothesis Based hereupon, we aimed to investigate...
Article
Full-text available
Background: The signalling peptide endotrophin is derived through proteolytic cleavage of the carboxyl-terminal during formation of type VI collagen. It is expressed by most descendants of the mesenchymal stem cells lineage, including adipocytes and fibroblasts, and have been proposed to be a central extracellular matrix hormone associated with se...
Article
Fat oxidation decreases with age, yet no studies have previously investigated if aging affects the maximal fat oxidation rate (MFO) during exercise in men and women differently. We hypothesized that increased age would be associated with a decline in MFO and this would be more pronounced in women due to menopause, compared with men. In this cross-s...
Article
The effect of oral glutathione (GSH) supplementation was studied in obese subjects with and without type 2 diabetes (T2DM) on measures of glucose homeostasis and markers of oxidative stress. Twenty subjects (10 patients with T2DM and 10 obese subjects) were recruited for the study, and randomized in a double-blinded placebo-controlled manner to con...
Article
Full-text available
Growing evidence supports that pharmacological application of growth differentiation factor 15 (GDF15) suppresses appetite but also promotes sickness-like behaviors in rodents via GDNF family receptor α-like (GFRAL)-dependent mechanisms. Conversely, the endogenous regulation of GDF15 and its physiological effects on energy homeostasis and behavior...
Article
INTRODUCTION: Decreased fasting and oral glucose-stimulated incretin hormone concentrations following moderate-intensity continuous endurance training interventions have been reported in glucose-tolerant people, however results are conflicting. The effect of more time-efficient, very low-volume, high-intensity interval training (HIT) on circulating...
Article
Full-text available
Background: Breast cancer survivors are encouraged to be physically active. A recent review suggests that football training is an effective exercise modality for women across the lifespan, positively influencing health variables such as strength, fitness and social well-being. However, football is a contact sport, potentially posing an increased r...
Article
Full-text available
The mechanisms by which exercise benefits human health remain incompletely understood. With the emergence of omics techniques, mapping of the molecular response to exercise is increasingly accessible. Here, we perform an untargeted metabolomics profiling of plasma from a randomized, within-subjects, crossover study of either endurance exercise or r...
Article
Full-text available
Prolonged physical inactivity in young adults may lead to deficiencies in musculoskeletal fitness, and thus a need exists to develop physical activity and exercise programmes that are effective of increasing musculoskeletal fitness. The aim of this study, therefore, was to investigate the effects of small-sided team handball training on lower limb...
Article
Full-text available
The peak fat oxidation rate (PFO) and the exercise intensity that elicits PFO (Fatmax) is associated with endurance performance during exercise primarily involving lower body musculature, but it remains elusive whether these associations are present during predominant upper body exercise. The aim was to investigate the relationship between PFO and...
Article
Full-text available
Background Actions to improve healthy aging and delay morbidity are crucial, given the global aging population. We believe that biological age estimation can help promote the health of the general population. Biological age reflects the heterogeneity in functional status and vulnerability to disease that chronological age cannot. Thus, biological a...
Preprint
Full-text available
Growing evidence supports that pharmacological application of growth differentiation factor 15 (GDF15) suppresses appetite but also promotes sickness-like behaviors in rodents via GDNF family receptor α-like (GFRAL)-dependent mechanisms 1,2 . Conversely, the endogenous regulation and secretion of GDF15 and its physiological effects on energy homeos...
Article
Full-text available
Statins are prescribed to treat hypercholesterolemia and to reduce the risk of cardiovascular disease. However, statin users frequently report myalgia, which can discourage physical activity or cause patients to discontinue statin use, negating the potential benefit of the treatment. Although a proposed mechanism responsible for Statin-Associated M...
Article
Full-text available
Introduction: The aging population emphasize the need for effective health promotion interventions. The workplace is a prioritized setting for health promotion to reach widely within a population. Body age can be used as a health-risk estimate and as a motivational tool to change health behavior. In this study we investigate body age-based interve...
Article
DICER is a key enzyme in microRNA (miRNA) biogenesis. Here we show that aerobic exercise training up-regulates DICER in adipose tissue of mice and humans. This can be mimicked by infusion of serum from exercised mice into sedentary mice and depends on AMPK-mediated signaling in both muscle and adipocytes. Adipocyte DICER is required for whole-body...
Article
Purpose To examine the exercise intensity and impact of 12 months of twice-weekly recreational football training on cardiorespiratory fitness (CRF), blood pressure (BP), resting heart rate (HRrest), body fat mass, blood lipids, inflammation, and health-related quality of life in women treated for early-stage breast cancer (BC). Methods Sixty-eight...
Article
Full-text available
Aims/hypothesis This study aimed to examine if beta-aminoisobutyric acid (BAIBA) is (i) secreted by skeletal muscle in humans during exercise, (ii) associated with insulin secretory function in vivo, and (iii) directly linked with acute glucose-mediated insulin release by pancreatic beta cells in vitro. Methods Following 2-weeks of single-leg immo...
Article
Full-text available
Macrophage infiltration in two subcutaneous adipose tissue depots and systemic low-grade inflammation were studied in post-obese (PO), obese (O), and control (C) subjects. Young males were recruited into PO: (n = 10, weight-loss avg. 26%, BMI: 26.6 ± 0.7, mean ±SEM kg/m2), O: (n = 10, BMI: 33.8 ± 1.0kg/m2) and C: (n = 10, BMI: 26.6 ± 0.6 kg/m2). PO...
Article
Introduction: The scientific outcome of Health Science PhD theses has been questioned by arguments suggesting that strategic motives are important for graduationamong clinical PhD graduates which may compromise scientific output and quality. This study aimed to investigate the scientific outcome of clinical PhD theses. Methods: A total of 841PhD...
Preprint
BACKGROUND Actions to improve healthy aging and delay morbidity are crucial, given the global aging population. We believe that biological age estimation can help promote the health of the general population. Biological age reflects the heterogeneity in functional status and vulnerability to disease that chronological age cannot. Thus, biological a...
Article
Female sex hormones fluctuate in a predictable manner throughout the menstrual cycle in eumenorrheic women. In studies conducted in both animal and humans, estrogen and progesterone have been found to exert individual metabolic effect during both rest and exercise, suggesting that estrogen may cause an increase in fat oxidation during exercise. How...
Article
Full-text available
Purpose: We tested the hypothesis that participation in small-sided team handball training could provide beneficial effects on cardiovascular and metabolic parameters in overweight premenopausal women with special focus on the importance of prior team handball experience. Methods: A 16-week RCT training intervention was conducted in overweight p...
Article
An attenuated ability to appropriately oxidize fat (metabolic inflexibility) has been associated with the development of obesity and type 2 diabetes. Previous studies have found that regular exercise training increases the body’s ability to oxidize fat during exercise, but also shown that fat oxidation at the same relative and absolute exercise int...
Article
Full-text available
Peak fat oxidation rate (PFO) and the intensity that elicits PFO (Fatmax) are commonly determined by a validated graded exercise test (GE) on a cycling‐ergometer with indirect calorimetry. However, for upper body exercise fat oxidation rates are not well elucidated and no protocol has been validated. Thus, our aim was to test validity and inter‐met...
Article
Objective To compare the dietary habits of children living in northern villages and in the capital of Greenland, given the reported transition from traditional to westernised diet in adults over recent decades, and to explore the association between consumption of marine mammals and fish (MMF) and the children’s metabolic profile and vitamin D stat...
Article
Full-text available
Maximal fat oxidation during exercise (MFO) and the exercise intensity eliciting MFO (Fatmax) are considered important factors related to metabolic health and performance. Numerous MFO and Fatmax data collection and analysis approaches have been applied, which may have influenced their estimation during an incremental graded exercise protocol. Desp...
Article
Full-text available
Maximal fat oxidation during exercise (MFO) and the exercise intensity eliciting MFO (Fatmax) are considered biological markers of metabolic health and performance. A wide range of studies have been performed to increase our knowledge about their regulation by exercise and/or nutritional intervention. However, numerous data collection and analysis...
Article
Full-text available
Abstract Aging decreases skeletal muscle mass and strength, but aerobic and resistance exercise training maintains skeletal muscle function. NAD+ is a coenzyme for ATP production and a required substrate for enzymes regulating cellular homeostasis. In skeletal muscle, NAD+ is mainly generated by the NAD+ salvage pathway in which nicotinamide phosph...
Article
Introduction: High intensity interval training (HIIT) has shown to be as effective as moderate intensity endurance training to improve metabolic health. However, the current knowledge on the effect of HIIT in older individuals is limited and it is uncertain whether the adaptations are sex specific. The aim was to investigate effects of HIIT on mito...
Article
Full-text available
Ceramide and diacylglycerol are linked to insulin resistance in rodents, but in humans the data are inconsistent. Insulin resistance is frequently observed with aging, but the role of ceramide and diacylglycerol is not clarified. Training improves metabolic health and, therefore, we aimed to elucidate the influence of age and high-intensity interva...
Article
The maximal fat oxidation (MFO), and the exercise intensity that elicits MFO (Fatmax), are considered excellent markers of fat metabolism during exercise. Besides individual’s biological characteristics (e.g. fed state, physical fitness level, sex, or age), data selection and analysis can affect MFO and Fatmax estimations, yet the effect is unknown...
Article
Plasma Free Fatty Acids (FFA) are a major contributor to whole body fat oxidation during exercise. However, to what extent, manipulating plasma FFA concentrations will influence whole body peak fat oxidation rate (PFO) during exercise remains elusive. In this study we aimed to increase plasma FFA concentrations through a combination of fasting and...
Article
Full-text available
Purpose The prevalence of lifestyle diseases has escalated, and effective exercise training programmes are warranted. This study tested the hypothesis that regular participation in small-sided team handball training could provide beneficial health effects on cardiovascular, skeletal, and muscular parameters in young adult untrained men. Method Twe...
Article
Full-text available
The author would like to correct the errors in the publication of the original article. The corrected details are given below for your reading.
Article
Introduction: Statins are widely used in both primary and secondary prevention of cardiovascular disease. The treatment increases the risk of muscle pain (myalgia) which can affect muscle function and levels of physical activity. We investigated whether statin-associated myalgia is coupled to impaired aerobic exercise performance including fat oxi...
Article
Purpose To analyze the diurnal variation of maximal fat oxidation (MFO) and the intensity that elicit MFO (Fat max ) in trained male athletes. Methods A total of 12 endurance-trained male athletes aged 24.7±4.1 participated in the study. We measured MFO, Fat max , maximum oxygen uptake (VO 2 max) and oxygen uptake percentage at ventilatory thresho...
Article
Sustaining a weight loss after a lifestyle intervention is challenging. The objective of the present study was to investigate if mitochondrial function is associated with the ability to maintain a weight loss. Sixty-eight former participants in an 11-12-week lifestyle intervention were recruited into 2 groups; weight loss maintenance (WLM; body mas...
Article
Aim To examine the effect of high‐intensity interval training (HIIT) on glucose clearance rates in skeletal muscle and explore the mechanism within the muscle. Methods Ten males with type 2 diabetes mellitus (T2DM) and ten matched healthy subjects performed 2 weeks of one‐legged HIIT (total of eight sessions, each comprised of 10 x 1 min ergometer...
Article
Background Myalgia is a common side effect to statin therapy, but the underlying mechanism is unknown. Statins may reduce Coenzyme Q10 (CoQ10) which is an essential electron carrier in the mitochondrial electron transport system, thereby impairing mitochondrial respiratory function potential leading to myalgia. Objectives To investigate whether st...
Article
Full-text available
Little is known about the combined associations of cardiorespiratory fitness (CRF) and hand grip strength (GS) with mortality in general adult populations. The purpose of this study was to compare the relative risk of mortality for CRF, GS, and their combination. In UK Biobank, a prospective cohort of > 0.5 million adults aged 40–69 years, CRF was...
Article
Simvastatin is a cholesterol-lowering drug that is prescribed to lower the risk of cardiovascular disease following high levels of blood cholesterol. There is a possible risk of new onset diabetes mellitus with statin treatment but the mechanisms behind are unknown. Coenzyme Q10 (CoQ10) supplementation has been found to improve glucose homeostasis...
Article
Purpose: Atherosclerosis is a major risk factor for cardiovascular disease (CVD) and is known to be an inflammatory process. Statin therapy decreases both cholesterol and inflammation and is used in primary and secondary prevention of CVD. However, a statin induced decrease of plasma concentrations of the antioxidant coenzyme Q10 (CoQ10), may prev...
Article
Reduced insulin sensitivity is observed with aging and often explained by decreased physical activity. The mechanisms involved are not clarified, but bioactive lipids may play a role. We aimed to evaluate the influence of age and cardiorespiratory fitness on ceramide and diacylglycerol content in muscle and key proteins in lipid metabolism and insu...
Article
The aim of the present study was to investigate if peak fat oxidation rate (PFO) is related to Ironman performance in female athletes. Thirty-six female Ironman athletes (age: 34±1 yrs, [21–45 yrs.] SEM [Range]) with a BMI of 22.1±2.0 kg/m2 [18.8–28.4 kg/m2], a body fat percentage of 24.8±1.0% [9.0–37.0%] and a V̇O2peak of 53.0±1.3 ml/min/kg [36.5–...