Influence of ambient temperature on resting energy expenditure in metabolically healthy men and women.

Background: It is not yet clear to what extent the physiological regulatory mechanisms that maintain core body temperature are reflected by changes in resting energy expenditure (REE). Particularly in indirect calorimetry with a canopy, the effects of short-term temperature exposures have not yet been investigated. This can be of relevance for the determination of REE in practice.

Determinants of increased muscle insulin sensitivity of exercise-trained versus sedentary normal weight and overweight individuals.

The athlete's paradox states that intramyocellular triglyceride accumulation associates with insulin resistance in sedentary but not in endurance-trained humans. Underlying mechanisms and the role of muscle lipid distribution and composition on glucose metabolism remain unclear. We compared highly trained athletes (ATHL) with sedentary normal weight (LEAN) and overweight-to-obese (OVWE) male and female individuals.

Harmonization of experimental procedures to assess mitochondrial respiration in human permeabilized skeletal muscle fibers.

Aim: High-resolution respirometry in human permeabilized muscle fibers is extensively used for analysis of mitochondrial adaptions to nutrition and exercise interventions, and is linked to athletic performance. However, the lack of standardization of experimental conditions limits quantitative inter- and intra-laboratory comparisons.

Methods: In our study, an international team of investigators measured mitochondrial respiration of permeabilized muscle fibers obtained from three biopsies (vastus lateralis) from the same healthy volunteer to avoid inter-individual variability.

Mitochondrial respiration in peripheral arterial disease depends on stage severity.

Peripheral arterial disease (PAD) is an increasing cause of morbidity and its severity is graded based on clinical manifestation. To investigate the influence of the different stages on myopathy of ischemic muscle we analysed severity-dependent effects of mitochondrial respiration in PAD. Eighteen patients with severe PAD, defined as chronic limb-threatening ischemia, 47 patients with intermittent claudication (IC) and 22 non-ischemic controls were analysed.

Immortalised murine R349P desmin knock-in myotubes exhibit a reduced proton leak and decreased ADP/ATP translocase levels in purified mitochondria.

Desmin gene mutations cause myopathies and cardiomyopathies. Our previously characterised R349P desminopathy mice, which carry the ortholog of the common human desmin mutation R350P, showed marked alterations in mitochondrial morphology and function in muscle tissue. By isolating skeletal muscle myoblasts from offspring of R349P desminopathy and p53 knock-out mice, we established an immortalised cellular disease model.

Dietary Intake of Athletes at the World Masters Athletics Championships as Assessed by Single 24 h Recall.

Proper dietary intake is important for masters athletes because of the physiological changes that occur with aging and the unique nutritional needs when competing at high levels. We evaluated the dietary intake of masters athletes competing at the World Masters Athletics Championships (outdoor games, Tampere, Finland, 2022, and indoor games, Torun, Poland, 2023). A total of 43 athletes (16 females and 27 males, mean age 59.

Loss of mitochondrial adaptation associates with deterioration of mitochondrial turnover and structure in metabolic dysfunction-associated steatotic liver disease.

Background: Obesity and type 2 diabetes frequently have metabolic dysfunction-associated steatotic liver disease (MASLD) including steatohepatitis (MASH). In obesity, the liver may adapt its oxidative capacity, but the role of mitochondrial turnover in MASLD remains uncertain.

Methods: This cross-sectional study compared individuals with class III obesity (n = 8/group) without (control, OBE CON; NAFLD activity score: 0.

Impact of physical fitness and exercise training on subcutaneous adipose tissue beiging markers in humans with and without diabetes and a high-fat diet-fed mouse model.

Aims: Exercise training induces white adipose tissue (WAT) beiging and improves glucose homeostasis and mitochondrial function in rodents. This could be relevant for type 2 diabetes in humans, but the effect of physical fitness on beiging of subcutaneous WAT (scWAT) remains unclear. This translational study investigates if beiging of scWAT associates with physical fitness in healthy humans and recent-onset type 2 diabetes and if a voluntary running wheel intervention is sufficient to induce beiging in mice.

Adjuvant pharmacological strategies for the musculoskeletal system during long-term space missions.

Despite 2 h of daily exercise training, muscle wasting and bone loss are still present after 6-month missions to the international space station. Some crew members lose bone much faster than others. In preparation for missions to the Moon and Mars, space agencies are therefore reviewing their countermeasure portfolios.

Oral fructose intake does not improve exercise, visual, or cognitive performance during acute normobaric hypoxia in healthy humans.

Introduction: The ability to metabolize fructose to bypass the glucose pathway in near-anaerobic conditions appears to contribute to the extreme hypoxia tolerance of the naked-mole rats. Therefore, we hypothesized that exogenous fructose could improve endurance capacity and cognitive performance in humans exposed to hypoxia.

Methods: In a randomized, double-blind, crossover study, 26 healthy adults (9 women, 17 men; 28.

Alterations of hepatic energy metabolism in murine models of obesity, diabetes and fatty liver diseases.

Background: Disturbed hepatic energy metabolism contributes to non-alcoholic fatty liver (NAFLD), but the development of changes over time and obesity- or diabetes-related mechanisms remained unclear.

Methods: Two-day old male C57BL/6j mice received streptozotocin (STZ) or placebo (PLC) and then high-fat (HFD) or regular chow diet (RCD) from week 4 (W4) to either W8 or W16, yielding control [CTRL = PLC + RCD], diabetes [DIAB = STZ + RCD], obesity [OBES = PLC + HFD] and diabetes-related non-alcoholic steatohepatitis [NASH = STZ + HFD] models. Mitochondrial respiration was measured by high-resolution respirometry and insulin-sensitive glucose metabolism by hyperinsulinemic-euglycemic clamps with stable isotope dilution.

Case Report: Muscle Wasting during Severe Sustained Hypoxia in Two Professional Mountaineers.

Purpose: Chronic exposure to hypoxia can induce muscle wasting in unaccustomed individuals. Detailed assessment of the effects of hypoxia on muscle tissue adaptation in elite mountaineers has not been performed. This study aims to assess muscle volume after exposure to normobaric hypoxia.

Comparison of trunk muscle exercises in supine position during short arm centrifugation with 1 g at centre of mass and upright in 1 g.

Spaceflight is associated with reduced antigravitational muscle activity, which results in trunk muscle atrophy and may contribute to post-flight postural and spinal instability. Exercise in artificial gravity (AG) performed short-arm human centrifugation (SAHC) is a promising multi-organ countermeasure, especially to mitigate microgravity-induced postural muscle atrophy. Here, we compared trunk muscular activity (mm.

Mitochondrial respiration is decreased in visceral but not subcutaneous adipose tissue in obese individuals with fatty liver disease.

Background & Aims: Adipose tissue dysfunction is involved in the development of insulin resistance and is responsible for excessive lipid delivery to other organs such as the liver. We tested the hypothesis that impaired mitochondrial function is a common feature of subcutaneous (SAT) and visceral adipose tissue (VAT), but may differently contribute to adipose tissue insulin resistance (IR) in obesity, non-alcoholic fatty liver (NAFL) and steatohepatitis (NASH).

Methods: In this cross-sectional study, we analyzed tissue-specific insulin sensitivity using stable isotope dilution and hyperinsulinemic-normoglycemic clamp tests.

Dietary lipid droplet structure in postnatal life improves hepatic energy and lipid metabolism in a mouse model for postnatal programming.

Early-life diets may have a long-lasting impact on metabolic health. This study tested the hypothesis that an early-life diet with large, phospholipid-coated lipid droplets (Concept) induces sustained improvements of hepatic mitochondrial function and metabolism. Young C57BL/6j mice were fed Concept or control (CTRL) diet from postnatal day 15 (PN15) to PN42, followed by western style (WSD) or standard rodent diet (AIN) until PN98.

INDY as a Therapeutic Target for Cardio-Metabolic Disease.

Decreased expression of the plasma membrane citrate transporter INDY (acronym I'm Not Dead, Yet) promotes longevity and protects from high-fat diet- and aging-induced metabolic derangements. Preventing citrate import into hepatocytes by different strategies can reduce hepatic triglyceride accumulation and improve hepatic insulin sensitivity, even in the absence of effects on body composition. These beneficial effects likely derive from decreased hepatic de novo fatty acid biosynthesis as a result of reduced cytoplasmic citrate levels.

High-intensity interval training for 12 weeks improves cardiovascular autonomic function but not somatosensory nerve function and structure in overweight men with type 2 diabetes.

Aims/hypothesis: It remains unclear whether and which modality of exercise training as a component of lifestyle intervention may exert favourable effects on somatosensory and autonomic nerve tests in people with type 2 diabetes.

Methods: Cardiovascular autonomic and somatosensory nerve function as well as intraepidermal nerve fibre density (IENFD) were assessed in overweight men with type 2 diabetes (type 2 diabetes, n = 20) and male glucose-tolerant individuals (normal glucose tolerance [NGT], n = 23), comparable in age and BMI and serving as a control group, before and after a supervised high-intensity interval training (HIIT) intervention programme over 12 weeks. Study endpoints included clinical scores, nerve conduction studies, quantitative sensory testing, IENFD, heart rate variability, postural change in systolic blood pressure and spontaneous baroreflex sensitivity (BRS).

Impaired Hepatic Mitochondrial Capacity in Nonalcoholic Steatohepatitis Associated With Type 2 Diabetes.

Objective: Individuals with type 2 diabetes are at higher risk of progression of nonalcoholic fatty liver (steatosis) to steatohepatitis (NASH), fibrosis, and cirrhosis. The hepatic metabolism of obese individuals adapts by upregulation of mitochondrial capacity, which may be lost during the progression of steatosis. However, the role of type 2 diabetes with regard to hepatic mitochondrial function in NASH remains unclear.

Physical Fitness and Cardiovascular Risk Factors in Novel Diabetes Subgroups.

Context: Physical inactivity promotes insulin resistance and increases the risk of diabetes and cardiovascular disease. Recently introduced clustering based on simple clinical measures identified diabetes subgroups (clusters) with different risks of diabetes-related comorbidities and complications.

Objective: This study aims to determine differences in physical fitness and cardiovascular risk between diabetes subgroups and a glucose-tolerant control group (CON).

Dietary palmitate and oleate differently modulate insulin sensitivity in human skeletal muscle.

Aims/hypothesis: Energy-dense nutrition generally induces insulin resistance, but dietary composition may differently affect glucose metabolism. This study investigated initial effects of monounsaturated vs saturated lipid meals on basal and insulin-stimulated myocellular glucose metabolism and insulin signalling.

Methods: In a randomised crossover study, 16 lean metabolically healthy volunteers received single meals containing safflower oil (SAF), palm oil (PAL) or vehicle (VCL).

Polymorphism Is Associated With Physical Activity-Mediated Metabolic Changes in Type 2 Diabetes.

Unlabelled: The rs540467 SNP in the gene, encoding a mitochondrial complex I subunit, has been shown to modulate adaptations to exercise training. Interaction effects with diabetes mellitus remain unclear. We assessed associations of habitual physical activity (PA) levels with metabolic variables and examined a possible modifying effect of the rs540467 SNP.