Correlation between skeletal muscle acetylcarnitine and phosphocreatine metabolism during submaximal exercise and recovery: interleaved 1H/31P MRS 7 T study

Acetylcarnitine is an essential metabolite for maintaining metabolic flexibility and glucose homeostasis. The in vivo behavior of muscle acetylcarnitine content during exercise has not been shown with magnetic resonance spectroscopy. Therefore, this study aimed to explore the behavior of skeletal muscle acetylcarnitine during rest, plantar flexion exercise, and recovery in the human gastrocnemius muscle under aerobic conditions. Ten lean volunteers and nine overweight volunteers participated in the study. A 7 T whole-body MR system with a double-tuned surface coil was used to acquire spectra from the gastrocnemius medialis. An MR-compatible ergometer was used for the plantar flexion exercise. Semi-LASER-localized 1H MR spectra and slab-localized 31P MR spectra were acquired simultaneously in one interleaved exercise/recovery session. The time-resolved interleaved 1H/31P MRS acquisition yielded excellent data quality. A between-group difference in acetylcarnitine metabolism over time was detected. Significantly slower τPCr recovery, τPCr on-kinetics, and lower Qmax in the overweight group, compared to the lean group was found. Linear relations between τPCr on-kinetics, τPCr recovery, VO2max and acetylcarnitine content were identified. In conclusion, we are the first to show in vivo changes of skeletal muscle acetylcarnitine during acute exercise and immediate exercise recovery with a submaximal aerobic workload using interleaved 1H/31P MRS at 7 T.

Thyroid hormone levels and BMI-SDS changes in adolescents with obesity

Background

Thyroid hormones play an important role in energy metabolism and weight control, explained mostly by inducing thermogenesis and increasing basal metabolic rate. It has recently been shown that FT4 levels are associated with food preferences, which might also play a role in modulating body weight. The aim of this longitudinal follow-up study was to analyze the relationship of thyroid hormones levels (FT4, TSH) at baseline with weight/BMI-SDS changes in children and adolescents with obesity.

Methods

Three hundred seventy-seven children and adolescents have been enrolled to this study and followed up without a systematic intervention program for 5.59 ± 1.85months. Children and adolescents were divided into three subgroups: 1) 144 adolescents with obesity (15-19 years), 2) 213 children with obesity (10-14.9 years), and 3) 20 lean adolescents (15-19 years). Thyroid hormones were measured at the baseline, and anthropometry was performed at the baseline and during the follow-up. For further analyses, participants were divided according to the BMI-SDS change into two groups: 1. with BMI-SDS decrease, and 2. with BMI-SDS increase.

Results

Adolescents with obesity from the BMI-SDS decrease group had significantly lower baseline serum levels of TSH compared to the BMI-SDS increase group (2.4 ± 1.0 vs. 3.2 ± 2.0mIU/l; p=0.005). Similar difference was found for FT4 levels (14.7 ± 2.2 in the BMI-SDS decrease group vs. 15.5 ± 2.7pmol/l in the BMI-SDS increase group, p=0.048). Moreover, the BMI-SDS decrease was present in significantly higher percentage of adolescents with obesity with lower than median TSH level compared to those with higher than median TSH level at baseline (61.1% vs 38.6%, p=0.011). Likewise, the BMI-SDS decrease was present in significantly higher percentage of adolescent females with obesity and lower than median FT4 compared to those with higher than median FT4 level at baseline (70.6% vs. 23.5%, p<0.001). No associations of baseline thyroid hormones with the BMI-SDS change were observed in children with obesity or lean adolescents.

Conclusion

Adolescents with obesity and increased BMI-SDS during the follow-up had significantly higher baseline levels of both TSH and FT4 compared to BMI-SDS decrease group. These results support the previous findings that higher FT4 in individuals with obesity may influence weight gain.

Habitual physical activity modulates cardiometabolic health in long-term testicular cancer survivors

PURPOSES

Physical activity (PA) may mitigate late cardiometabolic toxicity of cisplatin-based chemotherapy in testicular germ cell tumor (TGCT) long-term survivors. In this cross-sectional study, we evaluated the effects of habitual PA on metabolic syndrome (MetS) prevalence, and on the markers of cardiometabolic health and chronic inflammation in a population of long-term TGCT survivors.

METHODS

MetS prevalence was evaluated, and habitual PA was assessed using Baecke's habitual PA questionnaire in TGCT survivors (n=195, age=41.1±8.1years, 11.7±5.2years post-therapy) and healthy male controls (n=41, age=38.2±8.8years). Participants were stratified into low- and high-PA groups based on median values. Differences were examined between low- and high-PA groups (in the entire sample, TGCT survivor sub-samples differing in disease stage, and healthy controls), and between TGCT survivors and controls. Next, TGCT survivors were stratified into age- and BMI-matched sub-groups based on post-treatment time (5-15/15/30years) and number of chemotherapy cycles (≤3/>3), allowing us to detect age- and BMI-independent effects of habitual PA on cardiometabolic health in the given TGCT survivor sub-populations. A correlation matrix of habitual PA and sport activity with cardiometabolic and pro-inflammatory markers was generated.

RESULTS

TGCT survivors had higher MetS prevalence than controls. Patients with high habitual PA had lower waist circumference and Systemic Inflammation Index. Habitual PA scores correlated positively with HDL-cholesterol and negatively with waist circumference and atherogenic risk. Furthermore, cardiometabolic benefits of habitual PA were more pronounced in patients with disease stages 1 and 2. Effects of habitual PA on patients sub-populations stratified by chemotherapy dose and post-treatment time clearly showed that higher levels of habitual PA were associated with lower numbers of MetS components, except for patients who received more than 3 chemotherapy cycles and were examined more than15 years post-therapy.

CONCLUSIONS

Higher levels of habitual PA effectively mitigated cardiometabolic toxicity in TGCT survivors. Patients with higher cumulative doses of chemotherapy may need structured exercise interventions involving higher-intensity physical activity to achieve significant improvements in cardiometabolic health.

Activation of PDGF Signaling in the Adult Muscle Stem Cell Niche in Patients With Type 2 Diabetes Mellitus

CONTEXT

Type 2 diabetes mellitus (T2D) negatively affects muscle mass and function throughout life. Whether adult muscle stem cells contribute to the decrease in muscle health is not clear and insights into the stem cell niche are difficult to obtain.

OBJECTIVE

To establish the upstream signaling pathway of microRNA (miR)-501, a marker of activated myogenic progenitor cells, and interrogate this pathway in muscle biopsies from patients with T2D.

METHODS

Analysis of primary muscle cell cultures from mice and 4 normoglycemic humans and muscle biopsies from 7 patients with T2D and 7 normoglycemic controls using gene expression, information on histone methylation, peptide screening, and promoter assays.

RESULTS

miR-501 shares the promoter of its host gene, isoform 2 of chloride voltage-gated channel 5 (CLCN5-2), and miR-501 expression increases during muscle cell differentiation. We identify platelet-derived growth factor (PDGF) as an upstream regulator of CLCN5-2 and miR-501 via Janus kinase/signal transducer and activator of transcription. Skeletal muscle biopsies from patients with T2D revealed upregulation of PDGF (1.62-fold, P = .002), CLCN5-2 (2.85-fold, P = .03), and miR-501 (1.73-fold, P = .02) compared with normoglycemic controls. In addition, we observed a positive correlation of PDGF and miR-501 in human skeletal muscle (r = 0.542, P = .045, n = 14).

CONCLUSIONS

We conclude that paracrine signaling in the adult muscle stem cells niche is activated in T2D. Expression analysis of the PDGF-miR-501 signaling pathway could represent a powerful tool to classify patients in clinical trials that aim to improve muscle health and glucose homeostasis in patients with diabetes.

Supplementation-induced change in muscle carnosine is paralleled by changes in muscle metabolism, protein glycation and reactive carbonyl species sequestering

Carnosine is a performance-enhancing food supplement with a potential to modulate muscle energy metabolism and toxic metabolites disposal. In this study we explored interrelations between carnosine supplementation (2 g/day, 12 weeks) induced effects on carnosine muscle loading and parallel changes in (i) muscle energy metabolism, (ii) serum albumin glycation and (iii) reactive carbonyl species sequestering in twelve (M/F=10/2) sedentary, overweight-to-obese (BMI: 30.0+/-2.7 kg/m2) adults (40.1+/-6.2 years). Muscle carnosine concentration (Proton Magnetic Resonance Spectroscopy; 1H-MRS), dynamics of muscle energy metabolism (Phosphorus Magnetic Resonance Spectroscopy; 31P-MRS), body composition (Magnetic Resonance Imaging; MRI), resting energy expenditure (indirect calorimetry), glucose tolerance (oGTT), habitual physical activity (accelerometers), serum carnosine and carnosinase-1 content/activity (ELISA), albumin glycation, urinary carnosine and carnosine-propanal concentration (mass spectrometry) were measured. Supplementation-induced increase in muscle carnosine was paralleled by improved dynamics of muscle post-exercise phosphocreatine recovery, decreased serum albumin glycation and enhanced urinary carnosine-propanal excretion (all p<0.05). Magnitude of supplementation-induced muscle carnosine accumulation was higher in individuals with lower baseline muscle carnosine, who had lower BMI, higher physical activity level, lower resting intramuscular pH, but similar muscle mass and dietary protein preference. Level of supplementation-induced increase in muscle carnosine correlated with reduction of protein glycation, increase in reactive carbonyl species sequestering, and acceleration of muscle post-exercise phosphocreatine recovery.

Acute endurance exercise modulates growth differentiation factor 11 in cerebrospinal fluid of healthy young adults

OBJECTIVE

Strong evidence supports the benefits of exercise for healthy ageing, including reduced risk of neurodegenerative diseases. Recent studies suggested interorgan crosstalk as a key element of systemic adaptive response, however, the role of specific molecules in mediating exercise effects on the human brain are not fully understood. In the present study, we explored the exercise-related regulation of Growth Differentiation Factor 11 (GDF11) in cerebrospinal fluid (CSF) and blood.

METHODS

The samples of serum, plasma and CSF were obtained before and 60min after acute exercise (90min run) from twenty healthy young individuals. Additional serum and plasma samples were collected immediately after run. GDF11 protein content (immunoblotting), body composition (bioelectrical impedance), physical fitness (VO₂max, cycle spiroergometry) and cognitive functions (standardized computerized tests, Cogstate) were evaluated.

RESULTS

Running decreased GDF11 protein content in CSF (-20.6%. p=0.046), while GDF11 in plasma and serum were not regulated. Two GDF11-specific antibodies of different origin were used to corroborate this result. Individuals with higher physical fitness displayed greater exercise-induced decrease of GDF11 in CSF than those with lower physical fitness (p=0.025). VO₂max correlated positively with GDF11 in serum (r=0.63, p=0.020) as well as with the exercise-induced change in GDF11 levels in CSF (r=0.59, p=0.042). Indirect measure of blood-brain barrier permeability (i.e. CSF/serum albumin ratio) tended to positively correlate with CSF/serum GDF11 ratio (p=0.060). CSF levels of GDF11 correlated positively with cognitive functions, including working memory, both before and after run (p<0.05).

CONCLUSION

Running-induced down-regulation of the GDF11 protein in the cerebrospinal fluid of healthy young individuals indicates the potential role of GDF11 in the exercise-induced cross-talk between periphery and the brain.

Cerebrospinal fluid and plasma metabolomics of acute endurance exercise

Metabolomics has emerged as a powerful new tool in precision medicine. No studies have yet been published on the metabolomic changes in cerebrospinal fluid (CSF) produced by acute endurance exercise. CSF and plasma were collected from 19 young active adults (13 males and 6 females) before and 60 min after a 90-min monitored outdoor run. The median age, BMI, and VO₂ max of subjects was 25 years (IQR 22-31), 23.2 kg/m² (IQR 21.7-24.5), and 47 ml/kg/min (IQR 38-51), respectively. Targeted, broad-spectrum metabolomics was performed by liquid chromatography, tandem mass spectrometry (LC-MS/MS). In the CSF, purines and pyrimidines accounted for 32% of the metabolic impact after acute endurance exercise. Branch chain amino acids, amino acid neurotransmitters, fatty acid oxidation, phospholipids, and Krebs cycle metabolites traceable to mitochondrial function accounted for another 52% of the changes. A narrow but important channel of metabolic communication was identified between the brain and body by correlation network analysis. By comparing these results to previous work in experimental animal models, we found that over 80% of the changes in the CSF correlated with a cascade of mitochondrial and metabolic changes produced by ATP signaling. ATP is released as a co-neurotransmitter and neuromodulator at every synapse studied to date. By regulating brain mitochondrial function, ATP release was identified as an early step in the kinetic cascade of layered benefits produced by endurance exercise.

POS0912 THE EFFECT OF A 24-WEEK TRAINING ON METABOLIC PARAMETERS OF SKELETAL MUSCLE CELLS DERIVED FROM PATIENTS WITH ESTABLISHED IDIOPATHIC INFLAMMATORY MYOPATHIES

Background

Persistent muscle weakness after reduction of inflammation and resistance to immunosuppressive therapy in some patients with idiopathic inflammatory myopathies (IIM) suggest that not only immune but also non-immune mechanisms, such as mitochondrial abnormalities and metabolic disturbance, contribute to the pathogenesis of myositis. Exercise improves muscle function in IIM patients.

Objectives

To evaluate the effect of activities-of-daily-living, resistance and stability training on metabolic parameters of primary tissue culture myotubes established from muscle biopsies obtained from patients with established IIM.

Methods

Seven patients with established IIM underwent a 24-week supervised training focused on activities of daily living, muscle-strengthening and stability. Muscle biopsy was performed before and after the 24-week program in patients, and in healthy controls (n=9). Isolated skeletal muscle cells were grown and differentiated into myotubes for 6 days. After differentiation, the myotubes were cultured for another 24 hours in fresh medium, and then the conditioned media were collected, and the cells were harvested in TRIzol. A relative number of mitochondria was quantified by the ratio between mitochondrial gene (NADH dehydrogenase subunit 1) and reference nuclear gene (lipoprotein lipase) and determined by qPCR. Glucose, pyruvate, lactate, citrate, and fumarate were assessed in a conditioned medium using the comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometer.

Results

Patients significantly improved their muscle strength and endurance during the 24-week training [1]. There was no difference in the relative number of mitochondria in muscle tissue and myotubes between IIM patients and controls. A significant increase in the number of muscle tissue mitochondria was found in IIM patients after 24 weeks of training (p = 0.004), on average twofold. A similar effect was observed in cultured myotubes, with at least 4 of 7 IIM patients showing a twofold increase in mitochondria number.

Compared with myotubes from HC, myotubes derived from IIM patients consumed non-significantly more glucose and pyruvate from the culture medium; however, their glucose and pyruvate utilization were significantly reduced as a result of the 24-week training (p = 0.016 and p = 0.030, respectively). Skeletal muscle cells from IIM patients before training intervention did not differ from HC cells in the amount of released lactate; however, the lactate concentration in the conditioned medium from myotubes obtained from patients after the 24-week training was significantly lower (p = 0.016). When measuring citrate cycle products released into the culture medium, no difference in citrate and fumarate secretion was observed between myotubes of myositis patients and myotubes of healthy controls. In contrast, their release was significantly (p < 0.05) lower in myotubes from IIM patients after 24 weeks of training compared to muscle cells isolated prior to intervention.

Conclusion

In conclusion, 24 weeks of rehabilitation training in patients with IIM significantly increases the number of mitochondria in muscle tissue. Lower release of lactate and citrate cycle intermediates (citrate and fumarate) by myotubes obtained from patients after training intervention indicates an increase in mitochondrial functional capacity and confirms a positive response to exercise in muscles previously affected by the inflammatory process in IIM.

References

[1]Špiritović M, et al. Arthritis Res Ther. 2021;23(1):173.

Acknowledgements

This work was supported by the Ministry of Health of the Czech Republic grants nr. NU21-05-00322.

Disclosure of Interests

None declared

POS0480 VITAMIN D AND ITS RECEPTOR (VDR) GENE EXPRESSION IN SKELETAL MUSCLE ASSOCIATE WITH DISEASE AND MUSCLE FUNCTION PARAMETERS IN IDIOPATHIC INFLAMMATORY MYOPATHIES

Background

Idiopathic inflammatory myopathies (IIM) are chronic inflammatory disorders characterised, apart from extramuscular manifestations, by symmetrical progressive muscle weakness that may persist even after pharmacological suppression of inflammation, suggesting a significant involvement of nonimmune mechanisms. Low levels of vitamin D have been associated with several autoimmune diseases. Vitamin D is essential for the maintenance of skeletal muscle, and mounting evidence supports its relation to muscle damage, regeneration, and energy metabolism.

Objectives

The aim was to analyse vitamin D and the mediators of its function in muscle tissue of IIM patients, and to associate it with muscle health parameters.

Methods

A total of 46 IIM patients (40 females, 6 males; mean age 56.7±12.4; disease duration 6.5±6.0 years; dermatomyositis (21), polymyositis (18), necrotizing myopathy (7)) and 67 healthy controls (HC) (56 females, 11 males; mean age 50.9±14.7) were recruited. In total, 27 IIM patients participated in a 24-week intervention combining activities-of-daily-life, resistance and stability training [1]. Muscle biopsies from m. vastus lateralis (by Bergström needle) were obtained from 7 IIM patients before/after the 24-week training program, and from 13 control IIM patients, and 21 HC. Primary muscle cell cultures were established from these samples. Disease-associated parameters were evaluated by MYOACT/MITAX, MDI, VAS, HAQ, MMT8, FI-2 and CK, myoglobin, LD, ALT, AST, and CRP levels. Myostatin, as a myokine involved in muscle atrophy, was determined from serum samples by ELISA. Circulating concentrations of 25(OH) vitamin D (calcidiol) and active 1,25(OH) vitamin D (calcitriol) were measured by routine biochemistry techniques. Gene expression of vitamin D receptor (VDR) and 25-hydroxyvitamin D 1-alpha-hydroxylase (CYP27B1), an enzyme catalysing calcidiol conversion to hormonally active calcitriol, was determined by real-time PCR in muscle tissue and primary muscle cell cultures. Data are presented as mean ± standard deviation.

Results

Decreased levels of active 1,25(OH)D were observed in IIM patients compared to HC (125.0±45.4 vs. 164.7±49.2 pmol/l; p<0.0001). No difference was found for 25(OH)D. The 24-week training program did not have an effect on 25(OH)D or 1,25(OH)D serum levels. 25(OH)D was significantly associated with CRP (r=-0.322, p=0.040), MITAX (r=-0.380, p=0.021) and HAQ (r=-0.370, p=0.017) in IIM patients, even after correction for BMI, gluccocorticoid (GC) and vitamin D daily supplementation dose. After 24 weeks of exercise, active 1,25(OH)D was positively associated with MMT8 (r=0.866, p<0.0001), FI2 (r=0.608, p=0.013) and HAQ (r=-0.537, p=0.032) (corrected for BMI, GC and vit.D supplementation). Numerically higher gene expression of VDR and CYP27B1 was found in muscle tissue and primary muscle cells in IIM compared to HC. After the 24-week training, gene expression of both VDR and CYP27B1 in primary muscle cells decreased (p=0.031 and p=0.078, respectively). Associations of VDR gene expression with myoglobin (IIM: r=0.510, p=0.026; HC: r=0.473, p=0.035), MMT8 (IIM: r=-0.559, p=0.013), myostatin (IIM: r=-0.519, p=0.023; HC: r=0.586, p=0.005), and CK (HC: r=0.484, p=0.031) were observed in muscle tissue. CYP27B1 gene expression in the muscle was also associated with myoglobin (HC: r=0.501, p=0.024), MMT8 (IIM: r=-0.555, p=0.011) and VDR (IIM: r=0.561, p=0.012; HC: r=0.632, p=0.002).

Conclusion

Decrease of the biologically active form of vitamin D in circulation suggests an impairment of its metabolism in IIM. Vitamin D serum levels and gene expression of its receptor and activating enzyme in muscle tissue associate with disease activity and muscle function parameters indicating an important role of vitamin D in physical fitness and disease manifestations in IIM patients.

References

[1]Špiritović M, et al. Arthritis Res Ther. 2021;23(1):173.

Acknowledgements

This work was supported by the Ministry of Health of the Czech Republic grant nr. NU21-05-00322.

Disclosure of Interests

None declared.

Food preferences and thyroid hormones in children and adolescents with obesity

BACKGROUND

Thyroid hormones profoundly affect energy metabolism but their interrelation with food preference, which might contribute to childhood obesity development, are much less understood. In this study, we investigated if thyroid hormone levels are associated with specific modulation of food preference and potentially linked to the level of obesity in children and adolescents.

METHODS

Interrelations between food preference and peripheral thyroid activity were examined in a population of 99 non-obese and 101 obese children and adolescents (12.8 ± 3.6 years of age, 111/89 F/M) randomly selected from the patients of the Obesity and Metabolic Disease Out-patient Research Unit at National Institute for Children's Diseases in Bratislava in a period between December 2017 and March 2020.

RESULTS

Children and adolescents with obesity had a lower preference for food rich in high sucrose and high-complex carbohydrates, while the preference for protein and fat-containing food and that for dietary fibers did not differ between obese and nonobese. In adolescents with obesity, free thyroxine (FT4) correlated positively with the preference for a high protein and high fat-rich diet, irrespective of the fatty acid unsaturation level. Moreover, FT4 correlated negatively with the preference for dietary fibers, which has been also exclusively found in obese adolescents. Individuals with obesity with higher FT4 levels had higher systemic levels of AST and ALT than the population with lower FT4. Multiple regression analysis with age, sex, BMI-SDS, and FT4 as covariates revealed that FT4 and male gender are the major predictors of variability in the preference for a diet high in protein, fat, and monounsaturated fatty acids. FT4 was the sole predictor of the preference for a diet containing saturated and polyunsaturated fatty acids as well as for a diet low in fiber.

CONCLUSION

The link between free thyroxin levels and dietary preference for food rich in fat and protein is present exclusively in individuals with obesity. Higher serum FT4 was linked with elevated AST and ALT in children and adolescents with obesity, and FT4 was the best predictor for preference for food rich in fat and low in fiber. This may indicate that FT4 could contribute to the development of childhood obesity and its complications by modulating food preference.

Acute Effects of Different Exercise Intensities on Executive Function and Oculomotor Performance in Middle-Aged and Older Adults: Moderate-Intensity Continuous Exercise vs. High-Intensity Interval Exercise

A wealth of evidence has shown that a single bout of aerobic exercise can facilitate executive function. However, none of current studies on this topic have addressed whether the magnitude of the acute-exercise benefit on executive function and oculomotor performance is influenced by different aerobic exercise modes. The present study was thus aimed toward an investigation of the acute effects of high-intensity interval exercise (HIIE) vs. moderate-intensity continuous exercise (MICE) on executive-related oculomotor performance in healthy late middle-aged and older adults. Using a within-subject design, twenty-two participants completed a single bout of 30 min of HIIE, MICE, or a non-exercise-intervention (REST) session in a counterbalanced order. The behavioral [e.g., reaction times (RTs), coefficient of variation (CV) of the RT], and oculomotor (e.g., saccade amplitude, saccade latency, and saccadic peak velocity) indices were measured when participants performed antisaccade and prosaccade tasks prior to and after an intervention mode. The results showed that a 30-min single-bout of HIIE and MICE interventions shortened the RTs in the antisaccade task, with the null effect on the CV of the RT in the late middle-aged and older adults. In terms of oculomotor metrics, although the two exercise modes could not modify the performance in terms of saccade amplitudes and saccade latencies, the participants’ saccadic peak velocities while performing the oculomotor paradigm were significantly altered only following an acute HIIE intervention. The present findings suggested that a 30-min single-bout of HIIE and MICE interventions modulated post-exercise antisaccade control on behavioral performance (e.g., RTs). Nevertheless, the HIIE relative MICE mode appears to be a more effective aerobic exercise in terms of oculomotor control (e.g., saccadic peak velocities) in late middle-aged and older adults.

Chemotherapy-induced toxicity in patients with testicular germ cell tumors: The impact of physical fitness and regular exercise

BACKGROUND

Testicular germ cell tumors (TGCTs) represent ∼95% of testicular malignancies and are the most common type of malignancy in young male adults. While the incidence of TGCTs has increased during the last decades, the advances in treatment, namely introducing cisplatin into the chemotherapy regimen, have made TGCTs highly curable with the 10-year survival rate exceeding 95%. However, in parallel with increased cure rates, survivors may experience acute and late adverse effects of treatment, which increase morbidity, reduce the quality of life, and can be potentially life-threatening. Chemotherapy-related toxicities include cardiovascular and metabolic diseases, secondary cancer, avascular necrosis, cognitive impairment, cancer-related fatigue, poor mental health-related quality of life, nephrotoxicity, hypogonadism, neurotoxicity, pulmonary toxicity, anxiety, and depression. These treatment-related adverse effects have emerged as important survivorship dilemmas in TGCT cancer survivors. Recently, regular physical exercise has increasingly attracted research and clinical attention as an adjunct therapy for cancer patients.

PURPOSE

Herein, we review the most common chemotherapy-related adverse effects in TGCT survivors and clinical relevance of exercise and increased cardio-respiratory fitness in modulating chemotherapy-related toxicity and quality of life in this population.

RESULTS AND CONCLUSION

Exercise has positive effects on a spectrum of physical and psychosocial outcomes during and after cancer treatment, and current guidelines on exercise prescription in chronic diseases define the recommended dose (volume and intensity) of regular exercise for cancer survivors, highlighting regular, sufficiently intensive physical activity as an essential part of patients' care.

Effects of Short- and Long-Term Aerobic-Strength Training and Determinants of Walking Speed in the Elderly

BACKGROUND/AIMS

Walking speed (WS) is an objective measure of physical capacity and a modifiable risk factor of morbidity and mortality in the elderly. In this study, we (i) determined effects of 3-month supervised aerobic-strength training on WS, muscle strength, and habitual physical activity; (ii) evaluated capacity of long-term (21 months) training to sustain higher WS; and (iii) identified determinants of WS in the elderly.

METHODS

Volunteers (F 48/M 14, 68.4 ± 7.1 years) completed either 3-month aerobic-strength (3 × 1 h/week, n = 48) or stretching (active control, n = 14) intervention (study A). Thirty-one individuals (F 24/M 7) from study A continued in supervised aerobic-strength training (2 × 1 h/week, 21 months) and 6 (F 5/M 1) became nonexercising controls.

RESULTS

Three-month aerobic-strength training increased preferred and maximal WS (10-m walk test, p < 0.01), muscle strength (p < 0.01) and torque (p < 0.01) at knee extension, and 24-h habitual physical activity (p < 0.001), while stretching increased only preferred WS (p < 0.03). Effect of training on maximal WS was most prominent in individuals with baseline WS between 1.85 and 2.30 m·s-1. Maximal WS measured before intervention correlated negatively with age (r = -0.339, p = 0.007), but this correlation was weakened by the intervention (r = -0.238, p = 0.06). WS progressively increased within the first 9 months of aerobic-strength training (p < 0.001) and remained elevated during 21-month intervention (p < 0.01). Cerebellar gray matter volume (MRI) was positively associated with maximal (r = 0.54; p < 0.0001) but not preferred WS and explained >26% of its variability, while age had only minor effect.

CONCLUSIONS

Supervised aerobic-strength training increased WS, strength, and dynamics of voluntary knee extension as well as habitual physical activity in older individuals. Favorable changes in WS were sustainable over the 21-month period by a lower dose of aerobic-strength training. Training effects on WS were not limited by age, and cerebellar cortex volume was the key determinant of WS.

Alterations in activin A-myostatin-follistatin system associate with disease activity in inflammatory myopathies

OBJECTIVES

The aim of this study was to investigate the systemic and skeletal muscle levels of atrophy-associated myokines in patients with idiopathic inflammatory myopathies (IIM) and their association with clinical characteristics of myositis.

METHODS

A total of 94 IIM patients and 162 healthy controls were recruited. Of those, 20 IIM patients and 28 healthy controls underwent a muscle biopsy. Circulating concentrations of myostatin, follistatin, activin A and TGF-β1 were assessed by ELISA. The expression of myokines and associated genes involved in the myostatin signalling pathway in muscle tissue was determined by real-time PCR.

RESULTS

We report decreased levels of circulating myostatin (median 1817 vs 2659 pg/ml; P = 0.003) and increased follistatin (1319 vs 1055 pg/ml; P = 0.028) in IIM compared with healthy controls. Activin A levels were also higher in IIM (414 vs 309 pg/ml; P = 0.0005) compared with controls. Myostatin was negatively correlated to muscle disease activity assessed by physician on visual analogue scale (MDA) (r = -0.289, P = 0.015) and positively to manual muscle testing of eight muscles (r = 0.366, P = 0.002). On the other hand, follistatin correlated positively with MDA (r = 0.235, P = 0.047). Gene expression analysis showed higher follistatin (P = 0.003) and myostatin inhibitor follistatin-like 3 protein (FSTL3) (P = 0.008) and lower expression of activin receptor type 1B (ALK4) (P = 0.034), signal transducer SMAD3 (P = 0.023) and atrophy marker atrogin-1 (P = 0.0009) in IIM muscle tissue compared with controls.

CONCLUSION

This study shows lower myostatin and higher follistatin levels in circulation and attenuated expression of myostatin pathway signalling components in skeletal muscle of patients with myositis, a newly emerging pattern of the activin A-myostatin-follistatin system in muscle wasting diseases.

Altered dynamics of lipid metabolism in muscle cells from patients with idiopathic inflammatory myopathy is ameliorated by 6 months of training

KEY POINTS

Regular exercise improves muscle functional capacity and clinical state of patients with idiopathic inflammatory myopathy (IIM). In our study, we used an in vitro model of human primary muscle cell cultures, derived from IIM patients before and after a 6-month intensive supervised training intervention to assess the impact of disease and exercise on lipid metabolism dynamics. We provide evidence that muscle cells from IIM patients display altered dynamics of lipid metabolism and impaired adaptive response to saturated fatty acid load compared to healthy controls. A 6-month intensive supervised exercise training intervention in patients with IIM mitigated disease effects in their cultured muscle cells, improving or normalizing their capacity to handle lipids. These findings highlight the putative role of intrinsic metabolic defects of skeletal muscle in the pathogenesis of IIM and the positive impact of exercise, maintained in vitro by yet unknown epigenetic mechanisms.

ABSTRACT

Exercise improves skeletal muscle function, clinical state and quality of life in patients with idiopathic inflammatory myopathy (IIM). Our aim was to identify disease-related metabolic perturbations and the impact of exercise in skeletal muscle cells of IIM patients. Patients underwent a 6-month intensive supervised training intervention. Muscle function, anthropometric and metabolic parameters were examined and muscle cell cultures were established (m. vastus lateralis; Bergström needle biopsy) before and after training from patients and sedentary age/sex/body mass index-matched controls. [¹⁴ C]Palmitate was used to determine fat oxidation and lipid synthesis (thin layer chromatography). Cells were exposed to a chronic (3 days) and acute (3 h) metabolic challenge (the saturated fatty acid palmitate, 100 μm). Reduced oxidative (intermediate metabolites, -49%, P = 0.034) and non-oxidative (diglycerides, -38%, P = 0.013) lipid metabolism was identified in palmitate-treated muscle cells from IIM patients compared to controls. Three days of palmitate exposure elicited distinct regulation of oxidative phosphorylation (OxPHOS) complex IV and complex V/ATP synthase (P = 0.012/0.005) and adipose triglyceride lipase in patients compared to controls (P = 0.045) (immunoblotting). Importantly, 6 months of training in IIM patients improved lipid metabolism (CO₂ , P = 0.010; intermediate metabolites, P = 0.041) and activation of AMP kinase (P = 0.007), and nearly normalized palmitate-induced changes in OxPHOS proteins in myotubes from IIM patients, in parallel with improvements of patients' clinical state. Myotubes from IIM patients displayed altered dynamics of lipid metabolism and impaired response to metabolic challenge with saturated fatty acid. Our observations suggest that metabolic defects intrinsic to skeletal muscle could represent non-immune pathomechanisms, which can contribute to muscle weakness in IIM. A 6-month training intervention mitigated disease effects in muscle cells in vitro, indicating the existence of epigenetic regulatory mechanisms.

Cold Exposure Distinctively Modulates Parathyroid and Thyroid Hormones in Cold-Acclimatized and Non-Acclimatized Humans

Cold-induced activation of thermogenesis modulates energy metabolism, but the role of humoral mediators is not completely understood. We aimed to investigate the role of parathyroid and thyroid hormones in acute and adaptive response to cold in humans. Examinations were performed before/after 15 minutes of ice-water swimming (n = 15) or 120 to 150 minutes of cold-induced nonshivering thermogenesis (NST) applied to cold-acclimatized (n = 6) or non-acclimatized (n = 11) individuals. Deep-neck brown adipose tissue (BAT) was collected from non-acclimatized patients undergoing elective neck surgery (n = 36). Seasonal variations in metabolic/hormonal parameters of ice-water swimmers were evaluated. We found that in ice-water swimmers, PTH and TSH increased and free T3, T4 decreased after a 15-minute winter swim, whereas NST-inducing cold exposure failed to regulate PTH and free T4 and lowered TSH and free T3. Ice-water swimming-induced increase in PTH correlated negatively with systemic calcium and positively with phosphorus. In non-acclimatized men, NST-inducing cold decreased PTH and TSH. Positive correlation between systemic levels of PTH and whole-body metabolic preference for lipids as well as BAT volume was found across the 2 populations. Moreover, NST-cooling protocol-induced changes in metabolic preference for lipids correlated positively with changes in PTH. Finally, variability in circulating PTH correlated positively with UCP1/UCP1, PPARGC1A, and DIO2 in BAT from neck surgery patients. Our data suggest that regulation of PTH and thyroid hormones during cold exposure in humans varies by cold acclimatization level and/or cold stimulus intensity. Possible role of PTH in NST is indicated by its positive relationships with whole-body metabolic preference for lipids, BAT volume, and UCP1 content.

Multinuclear MRS at 7T Uncovers Exercise Driven Differences in Skeletal Muscle Energy Metabolism Between Young and Seniors

Purpose: Aging is associated with changes in muscle energy metabolism. Proton (¹H) and phosphorous (³¹P) magnetic resonance spectroscopy (MRS) has been successfully applied for non-invasive investigation of skeletal muscle metabolism. The aim of this study was to detect differences in adenosine triphosphate (ATP) production in the aging muscle by ³¹P-MRS and to identify potential changes associated with buffer capacity of muscle carnosine by ¹H-MRS.

Methods: Fifteen young and nineteen elderly volunteers were examined. ¹H and ³¹P-MRS spectra were acquired at high field (7T). The investigation included carnosine quantification using ¹H-MRS and resting and dynamic ³¹P-MRS, both including saturation transfer measurements of phosphocreatine (PCr), and inorganic phosphate (Pi)-to-ATP metabolic fluxes.

Results: Elderly volunteers had higher time constant of PCr recovery (τ_PCr) in comparison to the young volunteers. Exercise was connected with significant decrease in PCr-to-ATP flux in both groups. Moreover, PCr-to-ATP flux was significantly higher in young compared to elderly both at rest and during exercise. Similarly, an increment of Pi-to-ATP flux with exercise was found in both groups but the intergroup difference was only observed during exercise. Elderly had lower muscle carnosine concentration and lower postexercise pH. A strong increase in phosphomonoester (PME) concentration was observed with exercise in elderly, and a faster Pi:PCr kinetics was found in young volunteers compared to elderly during the recovery period.

Conclusion: Observations of a massive increment of PME concentration together with high Pi-to-ATP flux during exercise in seniors refer to decreased ability of the muscle to meet the metabolic requirements of exercise and thus a limited ability of seniors to effectively support the exercise load.

OP0138 CLUSTERIN ASSOCIATES WITH DISEASE MECHANISMS AND INFLAMMATION IN MYOSITIS PATIENTS

Background:

Idiopathic inflammatory myopathies (IIM, myositis) are a heterogeneous group of autoimmune muscle disorders characterized by skeletal muscle weakness and damage, inflammation and extramuscular manifestations. Recent findings suggest that immunological as well as nonimmunological processes, such as endoplasmic reticulum stress, hypoxia, mitochondrial and metabolic dysfunction are involved in the pathogenesis of IIMs [1]. Clusterin (CLU) has been reported to play a protective function in the development of tissue injury, inflammation and autoimmunity, and is involved in the maintenance of immune homeostasis [2].

Objectives:

This study aimed to explore a potential involvement of the circulating levels and skeletal muscle expression of CLU in pathogenic mechanisms of IIM.

Methods:

A total of 85 IIM patients and 86 healthy controls (HC) were recruited. In addition, 20 IIM patients and 21 HC underwent a muscle biopsy. Circulating concentrations of CLU were measured by ELISA. Serum cytokine profile of patients and HC was assessed by Cytokine 27-plex Assay. Immunohistochemical localisation of CLU was assessed in 10 IIM and 4 control muscle tissue specimens. The expression of CLU and myositis related cytokines in muscle tissue was determined by real-time PCR.

Results:

We observed a significant increase of circulating CLU in all IIM patients compared to HC (86.2 (71.6-99.0) vs. 59.6 (52.6-68.4) μg/mL, p < 0.0001). Moreover, CLU serum levels were positively correlated with myositis disease activity assessment (MYOACT) (r = 0.337, p = 0.008), myositis intention-to-treat activity index (MITAX) (r = 0.357, p = 0.004) and global disease assessment evaluated by physician (r = 0.309, p = 0.015). In addition to that, a multivariate redundancy analysis revealed a combined effect of serum CLU and cytokine profile (represented by cytokines and chemokines known to be involved in IIM) on disease activity measures. In muscle tissue, CLU mRNA was significantly increased in IIM patients compared to controls (p = 0.032) and correlated with IL-1β (r = 0.489, p = 0.034), IL-6 (r = 0.581, p = 0.009), TNF (r = 0.485, p = 0.035) and PGC-1α (r = 0.709, p = 0.001) mRNA. Immunohistochemistry revealed CLU accumulation in the cytoplasm of regenerating myofibers.

Conclusion:

Our results show an up-regulation of clusterin in circulation and skeletal muscle of IIM patients that associates with disease activity and inflammation, and its specific expression in regenerating myofibres. Based on our data and the known cytoprotective function of CLU we suggest an attempt of the organism to limit further muscle damage induced by myositis disease mechanisms.

References:

[1]Ernste FC, Reed AM. Idiopathic inflammatory myopathies: current trends in pathogenesis, clinical features, and up-to-date treatment recommendations. Mayo Clin Proc. 2013;88:83-105.

[2]Savkovic V, Gantzer H, Reiser U, Selig L, Gaiser S, Sack U, et al. Clusterin is protective in pancreatitis through anti-apoptotic and anti-inflammatory properties. Biochem Biophys Res Commun. 2007;356:431-7.

Acknowledgments:

This work was supported by GAUK 534217 and the Ministry of Health of the Czech Republic grants nr. 16-33746A and 16-33574A.

Disclosure of Interests:

None declared

OP0136 THE INFLUENCE OF LONG-TERM EXERCISE AND IN VITRO EXERCISE-MIMICKING STIMULATION ON THE PRODUCTION OF MYOKINES AND CYTOKINES IN MYOTUBES OF PATIENTS WITH CHRONIC IDIOPATHIC INFLAMMATORY MYOPATHIES

Background:

It has been demonstrated several times that endurance exercise has beneficial effects on the condition of patients with idiopathic inflammatory myopathies (IIM). Muscle contraction during exercise is a major stimulus for the release of myokines that are supposed to take part in the beneficial adaption to exercise.

Objectives:

The aim of this study was to find out how a six-month physiotherapy andin vitroexercise-mimicking treatment affect myokine and cytokine production in myotubes of IIM patients.

Methods:

Seven patients with chronic IIM took part in a six-month physiotherapy (stretching and strengthening), which significantly improved their muscle strength and endurance. IIM patients (n=7) before and after the six months exercise and their respective healthy counterparts (HC, n=9) underwent amusculus vastus lateralisbiopsy. Isolated skeletal muscle cells were grown, differentiated into myotubes, which were treated with a pharmacological cocktail: palmitate, forskolin and ionomycin (PFI) to mimic exercise-stimulated contractions in vitro. Myokine and cytokine concentrations produced by myotubes to the culture medium were analyzed with ELISA and the multiplex immunoassay, respectively. RT-PCR was used for the evaluation of myokine gene expression in the cultured myotubes.

Results:

Compared to myotubes of healthy controls, myotubes of IIM patient released more myostatin and activin A into the medium. The myostatin gene was expressed significantly more in muscle cells of patients than in healthy controls’ cells (p<0.05). After a six-month rehabilitation program, activin A secretion was four-fold reduced in myotubes of patients with IIM, while myostatin release and gene expression remained unchanged. In myotubes of IIM patients, less follistatin and more follistatin like 3 were detected in the culture medium compared to HC myotubes. Myotubes derived from IIM patients after six months of rehabilitation secreted twice as much follistatin and half the amount of follistatin like 3 into the medium than myotubes derived from IIM patients prior to rehabilitation (p<0.05). There was no difference in secretion of interleukin (IL) 6, IL-17, tumor necrosis factor (TNF) and vascular endothelial growth factor (VEGF) between myotubes of IIM patients and myotubes of HC. However, six-month exercise significantly (p<0.05) reduced release of IL-6, TNF and VEGF in myotubes of IIM patients. Contrary to our expectation, stimulation of PFI had no effect on the release of myostatin, activin A, follistatin and follistatin like 3, or the expression of their genes. PFI treatment significantly (p<0.05) increased IL-6 secretion in myotubes from HC and IIM patients prior to six months of rehabilitation. On the other hand, it was observed that myotubes of HC and IIM patients exposed to the PFI cocktail secreted significantly less inflammatory cytokines IL-17, TNF and VEGF into the medium compared to unstimulated myotubes (p<0.05).

Conclusion:

In conclusion, long-term exercise influenced the production of myokines and decreased release of inflammatory cytokines in myotubes of IIM patients.In vitroexercise-mimicking treatment increased the secretion of IL-6 and decreased the release of inflammatory cytokines as IL-17, TNF-α and VEGF in myotubes of patients with IIM and healthy individuals.

Acknowledgments:

This work was supported by the Ministry of Health of the Czech Republic grants nr. 16-33746A and donation 140.0000008.

Disclosure of Interests:

None declared

The effectiveness of two different multimodal training modes on physical performance in elderly

The study compared the effect of 12-week multimodal training programme performed twice a week at the regular exercise facility (REF) with the 12-week multimodal training programme performed three times per week as a part of the research programme (EX). Additionally, the study analysed how the experimental training programme affect the physical performance of cognitive healthy and mild cognitive impaired elderly (MCI). The REF training group included 19 elderly (65.00±3.62 years). The experimental training programme combined cognitively healthy (EXH: n=16; 66.3±6.42 years) and age-matched individuals with MCI (EXMCI: n=14; 66.00±4.79 years). 10m maximal walking speed (10mMWS), Five Times Sit-to-Stand Test (FTSS), maximal and relative voluntary contraction (MVC & rel. MVC) were analysed. The REF group improved in 10mMWS (t=2.431, p=.026), the MVC (t=-3.528, p=.002) and relative MVC (t=3.553, p=.002). The EXH group improved in FTSS (t=5.210, P=.000), MVC (t=2.771, p=.018) and relative MVC (t=-3.793, p=.004). EXMCI improved in FTSS (t=2.936, p=.012) and MVC (t=-2.276, p=.040). According to results, both training programmes sufficiently improved walking speed and muscle strength in cognitively healthy elderly. Moreover, the experimental training programme improved muscle strength in MCI elderly.

Relation between testosterone levels and body composition, physical functioning and selected biochemical parameters in adult males

INTRODUCTION

The objective of the study was to examine the relationship between the values of selected parameters of physical function, body composition, body mass index (BMI) and biochemical markers of metabolic health with the total testosterone (TT) levels in adult males. We aimed to analyse the correlation between these values and variations in the TT levels.

METHODS

A total of 17 subjects (age = 50.2 ± 8.1 years, TT = 11.4 ± 3.8nmol/l) were included in the study. Subjects were tested on physical function (1RM on leg press, bench-press, handgrip, VO2max), body composition (DXA), biochemical parameters (morning fasting blood samples).

RESULTS

TT was inversely correlated with abdominal circumference (AC) (p.

Acute and regular exercise distinctly modulate serum, plasma and skeletal muscle BDNF in the elderly

Brain-derived neurotrophic factor (BDNF) participates in orchestrating the adaptive response to exercise. However, the importance of transient changes in circulating BDNF for eliciting whole-body and skeletal muscle exercise benefits in humans remains relatively unexplored. Here, we investigated effects of acute aerobic exercise and 3-month aerobic-strength training on serum, plasma and skeletal muscle BDNF in twenty-two sedentary older individuals (69.0 ± 8.0 yrs., 9 M/13F). BDNF response to acute exercise was additionally evaluated in young trained individuals (25.1 ± 2.1 yrs., 3 M/5F). Acute aerobic exercise transiently increased serum BDNF in sedentary (16%, p = .007) but not in trained elderly or young individuals. Resting serum or plasma BDNF was not regulated by exercise training in the elderly. However, subtle training-related changes of serum BDNF positively correlated with improvements in walking speed (R = 0.59, p = .005), muscle mass (R = 0.43, p = .04) and cognitive performance (R = 0.41, p = .05) and negatively with changes in body fat (R = -0.43, p = .04) and triglyceridemia (R = -0.53, p = .01). Individuals who increased muscle BDNF protein in response to 3-month training (responders) displayed stronger acute exercise-induced increase in serum BDNF than non-responders (p = .006). In addition, muscle BDNF protein content positively correlated with type II-to-type I muscle fiber ratio (R = 0.587, p = .008) and with the rate of post-exercise muscle ATP re-synthesis (R = 0.703, p = .005). Contrary to serum, acute aerobic exercise resulted in a decline of plasma BDNF 1 h post-exercise in both elderly-trained (-34%, p = .002) and young-trained individuals (-48%, p = .034). Acute circulating BDNF regulation by exercise was dependent on the level of physical fitness and correlated with training-induced improvements in metabolic and cognitive functions. Our observations provide an indirect evidence that distinct exercise-induced changes in serum and plasma BDNF as well as training-related increase in muscle BDNF protein, paralleled by improvements in muscle and whole-body clinical phenotypes, are involved in the coordinated adaptive response to exercise in humans.

Ultralong TE In Vivo 1 H MR Spectroscopy of Omega-3 Fatty Acids in Subcutaneous Adipose Tissue at 7 T

BACKGROUND

Omega-3 (n-3) fatty acids (FA) play and important role in neural development and other metabolic diseases such as obesity and diabetes. The knowledge about the in vivo content and distribution of n-3 FA in human body tissues is not well established and the standard quantification of FA is invasive and costly.

PURPOSE

To detect omega-3 (n-3 CH3 ) and non-omega-3 (CH3 ) methyl group resonance lines with echo times up to 1200 msec, in oils, for the assessment of n-3 FA content, and the n-3 FA fraction in adipose tissue in vivo.

STUDY TYPE

Prospective technical development.

POPULATION

Three oils with different n-3 FA content and 24 healthy subjects.

FIELD STRENGTH/SEQUENCE

Single-voxel MR spectroscopy (SVS) with a point-resolved spectroscopy (PRESS) sequence with an echo time (TE) of 1000 msec at 7 T.

ASSESSMENT

Knowledge about the J-coupling evolution of both CH3 resonances was used for the optimal detection of the n-3 CH3 resonance line at a TE of 1000 msec. The accuracy of the method in oils and in vivo was validated from a biopsy sample with gas chromatography analysis.

STATISTICAL TESTS

SVS data were compared to gas chromatography with the Pearson correlation coefficient.

RESULTS

T2 relaxation times in oils were assessed as follows: CH2 , 65 ± 22 msec; CH3 , 325 ± 7 msec; and n-3 CH3 , 628 ± 34 msec. The n-3 FA fractions from oil phantom experiments (n = 3) were in agreement with chromatography analysis and the comparison of in vivo obtained data with the results of chromatography analysis (n = 5) yielded a significant correlation (P = 0.029).

DATA CONCLUSION

PRESS with ultralong-TE can detect and quantify the n-3 CH3 signal in vivo at 7 T.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:71-82.

The Potential of Carnosine in Brain-Related Disorders: A Comprehensive Review of Current Evidence

Neurological, neurodegenerative, and psychiatric disorders represent a serious burden because of their increasing prevalence, risk of disability, and the lack of effective causal/disease-modifying treatments. There is a growing body of evidence indicating potentially favourable effects of carnosine, which is an over-the-counter food supplement, in peripheral tissues. Although most studies to date have focused on the role of carnosine in metabolic and cardiovascular disorders, the physiological presence of this di-peptide and its analogues in the brain together with their ability to cross the blood-brain barrier as well as evidence from in vitro, animal, and human studies suggest carnosine as a promising therapeutic target in brain disorders. In this review, we aim to provide a comprehensive overview of the role of carnosine in neurological, neurodevelopmental, neurodegenerative, and psychiatric disorders, summarizing current evidence from cell, animal, and human cross-sectional, longitudinal studies, and randomized controlled trials.

Distinctive Effects of Aerobic and Resistance Exercise Modes on Neurocognitive and Biochemical Changes in Individuals with Mild Cognitive Impairment

Background:

Decreased levels of the neuroprotective growth factors, low-grade inflammation, and reduced neurocognitive functions during aging are associated with neurodegenerative diseases, such as Alzheimer’s disease. Physical exercise modifies these disadvantageous phenomena while a sedentary lifestyle promotes them.

Purpose:

The purposes of the present study included investigating whether both aerobic and resistance exercise produce divergent effects on the neuroprotective growth factors, inflammatory cytokines, and neurocognitive performance, and further exploring whether changes in the levels of these molecular biomarkers are associated with alterations in neurocognitive performance.

Methods:

Fifty-five older adults with amnestic MCI (aMCI) were recruited and randomly assigned to an aerobic exercise (AE) group, a resistance exercise (RE) group, or a control group. The assessment included neurocognitive measures [e.g., behavior and event-related potential (ERP)] during a task-switching paradigm, as well as circulating neuroprotective growth factors (e.g., BDNF, IGF-1, VEGF, and FGF-2) and inflammatory cytokine (e.g., TNF-α, IL-1β, IL-6, IL-8, and IL-15) levels at baseline and after either a 16-week aerobic or resistance exercise intervention program or a control period.

Results:

Aerobic and resistance exercise could effectively partially facilitate neurocognitive performance [e.g., accuracy rates (ARs), reaction times during the heterogeneous condition, global switching cost, and ERP P3 amplitude] when the participants performed the task switching paradigm although the ERP P2 components and P3 latency could not be changed. In terms of the circulating molecular biomarkers, the 16-week exercise interventions did not change some parameters (e.g., leptin, VEGF, FGF-2, IL-1β, IL-6, and IL-8). However, the peripheral serum BDNF level was significantly increased, and the levels of insulin, TNF-α, and IL-15 levels were significantly decreased in the AE group, whereas the RE group showed significantly increased IGF-1 levels and decreased IL-15 levels. The relationships between the changes in neurocognitive performance (AR and P3 amplitudes) and the changes in the levels of neurotrophins (BDNF and IGF-1)/inflammatory cytokines (TNF-α) only approached significance.

Conclusion:

These findings suggested that in older adults with aMCI, not only aerobic but also resistance exercise is effective with regard to increasing neurotrophins, reducing some inflammatory cytokines, and facilitating neurocognitive performance. However, the aerobic and resistance exercise modes likely employed divergent molecular mechanisms on neurocognitive facilitation.

An acute bout of aerobic or strength exercise specifically modifies circulating exerkine levels and neurocognitive functions in elderly individuals with mild cognitive impairment

Although exercise is an effective way to decrease the risk of developing Alzheimer's disease, the biological basis for such benefits from the different exercise modes remains elusive. The present study thus aimed (i) to investigate the effects of acute aerobic or resistance exercise on neurocognitive performances and molecular markers when performing a cognitive task involving executive functioning in older adults with amnestic mild cognitive impairment (aMCI), and (ii) to explore relationships of acute exercise-induced neurocognitive changes with changes in circulating levels of neuroprotective growth factors (e.g., BDNF, IGF-1, VEGF, and FGF-2, collectively termed 'exerkines'), elicited by different acute exercise modes. Sixty-six older adults with aMCI were recruited and randomly assigned to an aerobic exercise (AE) group, a resistance exercise (RE) group, or a non-exercise-intervention (control) group. The behavioral [i.e., accuracy rate (AR) and reaction time (RT)] and electrophysiological [i.e., event-related potential (ERP) P3 latency and amplitude collected from the Fz, Cz, and Pz electrodes] indices were simultaneously measured when participants performed a Flanker task at baseline and after either an acute bout of 30 min of moderate-intensity AE, RE or a control period. Blood samples were taken at three time points, one at baseline (T1) and two after an acute exercise intervention (T2 and T3: before and after cognitive task test, respectively). The results showed that the acute AE and RE not only improved behavioral (i.e., RTs) performance but also increased the ERP P3 amplitudes in the older adults with aMCI. Serum FGF-2 levels did not change with acute aerobic or resistance exercise. However, an acute bout of aerobic exercise significantly increased serum levels of BDNF and IGF-1 and tended to increase serum levels of VEGF in elderly aMCI individuals. Acute resistance exercise increased only serum IGF-1 levels. However, the exercise-induced elevated levels of these molecular markers returned almost to baseline levels in T3 (about 20 min after acute exercise). In addition, changes in the levels of neurotrophic and angiogenic factors were not correlated with changes in RTs and P3 amplitudes. The present findings of changes in neuroprotective growth factors and neurocognitive performances through acute AE or RE suggest that molecular and neural prerequisites for exercise-dependent plasticity are preserved in elderly aMCI individuals. However, the distinct pattern of changes in circulating molecular biomarkers induced by two different exercise modes in aMCI elderly individuals and the potentially interactive mechanisms of the effects of BDNF, IGF-1, and VEGF on amyloid-β provide a basis for future long-term exercise intervention to investigate whether AE relative to RE might be more effective in prevention/treatment of an early stage neurodegenerative disease.

Muscular Power during a Lifting Task Increases after Three Months of Resistance Training in Overweight and Obese Individuals

Background: This study evaluates the effect on power produced during a modified lifting task in the overweight and obese after three months of either resistance or aerobic training. Methods: Seventeen male subjects divided randomly into two groups performed deadlift and deadlift high pull, both with increasing weights up to maximal power, prior to and after the training programs (three sessions per week). Results: Their mean power increased significantly during the deadlift at 20 kg (14.3%, p = 0.026), 30 kg (17.7%, p = 0.008), 40 kg (16.5%, p = 0.011), 50 kg (14.5%, p = 0.020), and 60 kg (14.3%, p = 0.021) and during the deadlift high pull at 30 kg (9.9%, p = 0.037), 40 kg (10.1%, p = 0.035), and 50 kg (8.2%, p = 0.044) after the resistance training. However, the group that participated in the aerobic training failed to show any significant changes in power performance during either the deadlift or deadlift high pull. Conclusion: Three months of resistance training enhances power outputs during a lifting task with weights from 30 to 50 kg (~40–60% of 1-repetition maximum) in the overweight and obese. Because this test was sensitive in revealing pre-post training changes in lifting performance, it should be implemented in the functional diagnostics for overweight and obese individuals and also complement existing testing methods.

Three months of resistance training in overweight and obese individuals improves reactive balance control under unstable conditions

BACKGROUND

Contrary to static and dynamic balance, there is a lack of scientific evidence on the training induced changes in reactive balance control in response to unexpected perturbations in overweight and obese individuals.

OBJECTIVE

This study evaluates the effect of 3 months of resistance and aerobic training programs on postural responses to unexpected perturbations under stable and unstable conditions in the overweight and obese.

METHODS

A group of 17 overweight and obese subjects, divided into two groups, underwent either resistance or aerobic training for a period of 3 months (3 sessions per week). Prior to and after completing the training, they performed the load release balance test while standing on either a stable or unstable surface, with eyes open and closed.

RESULTS

Peak posterior center of pressure (CoP) displacement, and the time to peak posterior CoP displacement during a bipedal stance on a foam surface with eyes open (17.3%, p = 0.019 and 15.4%, p = 0.029) and eyes closed (15.0%, p = 0.027 and 13.2%, p = 0.034), decreased significantly. In addition, the total anterior to posterior CoP displacement, and the time from peak anterior to peak posterior CoP displacement, both with eyes open (18.1%, p = 0.017 and 12.2%, p = 0.040) and eyes closed (16.3%, p = 0.023 and 11.7%, p = 0.044), also significantly decreased. However, after completing the resistance training, the parameters registered while standing on a stable platform, both with eyes open and closed, did not change significantly. The group that underwent an aerobic training also failed to show any significant changes in parameters of the load release balance test.

CONCLUSION

Three months of resistance training in overweight and obese subjects improves reactive balance control in response to unexpected perturbations under unstable conditions, both with and without visual cues. Due to the fact that this unstable load release balance test was found to be sensitive in revealing post-training changes, it would be suitable for implementing in the functional diagnostic for this group, in addition to complementing existing testing methods.

Unilateral Stability and Visual Feedback Body Control Improves After Three-Month Resistance Training in Overweight Individuals

The authors evaluated the effect of 3 months of resistance and aerobic training (3 sessions/week) on body balance in a group of 25 overweight and obese individuals. Prior to and after the training, they performed static and task-oriented balance tests under various conditions. Mean center of pressure (CoP) velocity and mean trace length of the CoP in the y-axis registered during a one-legged stance significantly decreased after the resistance training (19.1%, p = .024; 29.3%, p = .009). Mean trace length of the CoP in the y-axis decreased significantly also during a bipedal stance on a foam surface with eyes open and closed (10.9%, p = .040; 18.2%, p = .027). In addition, mean CoP distance and mean squared CoP distance in the anteroposterior direction during a visually guided center of mass (CoM) tracking task significantly improved (14.7%, p = .033; 28.2%, p = .016). However, only mean trace length of the CoP in the y-axis during a bipedal stance on a foam surface with eyes open and closed significantly decreased after the aerobic training (10.3%, p = .047; 16.5%, p = .029). It may be concluded that resistance training is more efficient for the improvement of the anteroposterior unilateral stability and the accuracy of the regulation of the CoM anteroposterior position than aerobic training in overweight and obese individuals.

Upper and Lower Body Muscle Power Increases After 3-Month Resistance Training in Overweight and Obese Men

This study evaluates the effect of 3 months resistance and aerobic training on muscle strength and power in 17 male overweight and obese men. Subjects underwent either a resistance or aerobic training for a period of 3 months (three sessions per week). Peak isometric force, rate of force development, peak power and height of countermovement and squat jumps, reactive strength index, and mean power in the concentric phase of bench presses were all assessed prior to and after completing the training program. Results identified a significant increase of mean power during both countermovement bench presses at 30 kg (18.6%, p = .021), 40 kg (14.6%, p = .033), and 50 kg (13.1%, p = .042) and concentric-only bench presses at 30 kg (19.6%, p = .017) and 40 kg (13.9%, p = .037) after the resistance training. There was also a significant increase in the height of the jump (12.8%, p = .013), peak power (10.1%, p = .026), and peak velocity (9.7%, p = .037) during the countermovement jump and height of the jump (11.8%, p = .019), peak power (9.6%, p = .032), and peak velocity (9.5%, p = .040) during the squat jump. There were no significant changes in the reactive strength index, peak force, and the rate of force development after the resistance training. The aerobic group failed to show any significant improvements in these parameters. It may be concluded that 3 months of resistance training without caloric restriction enhances upper and lower body muscle power in overweight and obese men.

Skeletal muscle alkaline Pi pool is decreased in overweight-to-obese sedentary subjects and relates to mitochondrial capacity and phosphodiester content

Defects in skeletal muscle energy metabolism are indicative of systemic disorders such as obesity or type 2 diabetes. Phosphorus magnetic resonance spectroscopy ((31)P-MRS), in particularly dynamic (31)P-MRS, provides a powerful tool for the non-invasive investigation of muscular oxidative metabolism. The increase in spectral and temporal resolution of (31)P-MRS at ultra high fields (i.e., 7T) uncovers new potential for previously implemented techniques, e.g., saturation transfer (ST) or highly resolved static spectra. In this study, we aimed to investigate the differences in muscle metabolism between overweight-to-obese sedentary (Ob/Sed) and lean active (L/Ac) individuals through dynamic, static, and ST (31)P-MRS at 7T. In addition, as the dynamic (31)P-MRS requires a complex setup and patient exercise, our aim was to identify an alternative technique that might provide a biomarker of oxidative metabolism. The Ob/Sed group exhibited lower mitochondrial capacity, and, in addition, static (31)P-MRS also revealed differences in the Pi-to-ATP exchange flux, the alkaline Pi-pool, and glycero-phosphocholine concentrations between the groups. In addition to these differences, we have identified correlations between dynamically measured oxidative flux and static concentrations of the alkaline Pi-pool and glycero-phosphocholine, suggesting the possibility of using high spectral resolution (31)P-MRS data, acquired at rest, as a marker of oxidative metabolism.

Improved spectral resolution and high reliability of in vivo (1) H MRS at 7 T allow the characterization of the effect of acute exercise on carnosine in skeletal muscle

The aims of this study were to observe the behavior of carnosine peaks in human soleus (SOL) and gastrocnemius (GM) muscles following acute exercise, to determine the relaxation times and to assess the repeatability of carnosine quantification by (1) H MRS at 7 T. Relaxation constants in GM and SOL were measured by a stimulated echo acquisition mode (STEAM) localization sequence. For T1 measurement, an inversion recovery sequence was used. The repeatability of the measurement and the absolute quantification of carnosine were determined in both muscles in five healthy volunteers. For absolute quantification, an internal water reference signal was used. The effect of acute exercise on carnosine levels and resonance lines was tested in eight recreational runners/cyclists. The defined carnosine measurement protocol was applied three times - before and twice after (approximately 20 and 40 min) a 1-h submaximal street run and additional toe-hopping. The measured T1 relaxation times for the C2-H carnosine peak at 7 T were 2002 ± 94 and 1997 ± 259 ms for GM and SOL, respectively, and the T2 times were 95.8 ± 9.4 and 81.0 ± 21.8 ms for GM and SOL, respectively. The coefficient of variation of the carnosine quantification measurement was 9.1% for GM and 6.3% for SOL, showing high repeatability, and the intraclass correlation coefficients (ICCs) of 0.93 for GM and 0.98 for SOL indicate the high reliability of the measurement. Acute exercise did not change the concentration of carnosine in the muscle, but affected the shape of the resonance lines, in terms of the shifting and splitting into doublets. Carnosine measurement by (1) H MRS at 7 T in skeletal muscle exhibits high repeatability and reliability. The observed effects of acute exercise were more prominent in GM, probably as a result of the larger portion of glycolytic fibers in this muscle and the more pronounced exercise-induced change in pH. Our results support the application of the MRS-based assessment of carnosine for pH measurement in muscle compartments.

Depth-resolved surface coil MRS (DRESS)-localized dynamic (31) P-MRS of the exercising human gastrocnemius muscle at 7 T

Dynamic (31) P-MRS with sufficiently high temporal resolution enables the non-invasive evaluation of oxidative muscle metabolism through the measurement of phosphocreatine (PCr) recovery after exercise. Recently, single-voxel localized (31) P-MRS was compared with surface coil localization in a dynamic fashion, and was shown to provide higher anatomical and physiological specificity. However, the relatively long TE needed for the single-voxel localization scheme with adiabatic pulses limits the quantification of J-coupled spin systems [e.g. adenosine triphosphate (ATP)]. Therefore, the aim of this study was to evaluate depth-resolved surface coil MRS (DRESS) as an alternative localization method capable of free induction decay (FID) acquisition for dynamic (31) P-MRS at 7 T. The localization performance of the DRESS sequence was tested in a phantom. Subsequently, two dynamic examinations of plantar flexions at 25% of maximum voluntary contraction were conducted in 10 volunteers, one examination with and one without spatial localization. The DRESS slab was positioned obliquely over the gastrocnemius medialis muscle, avoiding other calf muscles. Under the same load, significant differences in PCr signal drop (31.2 ± 16.0% versus 43.3 ± 23.4%), end exercise pH (7.06 ± 0.02 versus 6.96 ± 0.11), initial recovery rate (0.24 ± 0.13 mm/s versus 0.35 ± 0.18 mm/s) and maximum oxidative flux (0.41 ± 0.14 mm/s versus 0.54 ± 0.16 mm/s) were found between the non-localized and DRESS-localized data, respectively. Splitting of the inorganic phosphate (Pi) signal was observed in several non-localized datasets, but in none of the DRESS-localized datasets. Our results suggest that the application of the DRESS localization scheme yielded good spatial selection, and provided muscle-specific insight into oxidative metabolism, even at a relatively low exercise load. In addition, the non-echo-based FID acquisition allowed for reliable detection of ATP resonances, and therefore calculation of the specific maximum oxidative flux, in the gastrocnemius medialis using standard assumptions about resting ATP concentration in skeletal muscle.

Interrelation of 31P-MRS metabolism measurements in resting and exercised quadriceps muscle of overweight-to-obese sedentary individuals

Phosphorus magnetic resonance spectroscopy ((31)P-MRS) enables the non-invasive evaluation of muscle metabolism. Resting Pi-to-ATP flux can be assessed through magnetization transfer (MT) techniques, and maximal oxidative flux (Q(max)) can be calculated by monitoring of phosphocreatine (PCr) recovery after exercise. In this study, the muscle metabolism parameters of 13 overweight-to-obese sedentary individuals were measured with both MT and dynamic PCr recovery measurements, and the interrelation between these measurements was investigated. In the dynamic experiments, knee extensions were performed at a workload of 30% of maximal voluntary capacity, and the consecutive PCr recovery was measured in a quadriceps muscle with a time resolution of 2 s with non-localized (31)P-MRS at 3 T. Resting skeletal muscle metabolism was assessed through MT measurements of the same muscle group at 7 T. Significant linear correlations between the Q(max) and the MT parameters k(ATP) (r = 0.77, P = 0.002) and F(ATP) (r = 0.62, P = 0.023) were found in the study population. This would imply that the MT technique can possibly be used as an alternative method to assess muscle metabolism when necessary (e.g. in individuals after stroke or in uncooperative patients).

Adipokine protein expression pattern in growth hormone deficiency predisposes to the increased fat cell size and the whole body metabolic derangements

CONTEXT

GH deficiency (GHD) in adults is associated with central adiposity, dyslipidemia, and insulin resistance.

OBJECTIVE

The objective of the study was to test the hypothesis that GHD might change the spectrum of adipokines and thus influence the adipose tissue and the whole-body metabolic and inflammatory status leading to development of insulin resistance.

DESIGN

This was a single-center observational study with a cross-sectional design.

PARTICIPANTS AND METHODS

Protein arrays were used to characterize adipokines expressed in the sc adipose tissue obtained from young GHD adults and compared with age-, gender-, and body mass index (BMI)-matched group of healthy individuals. All subjects underwent an oral glucose tolerance test, euglycemic hyperinsulinemic clamp, and magnetic resonance imaging examination.

RESULTS

Presence of abdominal obesity, enlarged adipocytes, increased circulating high-sensitivity C-reactive protein, impaired glucose tolerance, and decreased insulin action were found in GHD. Changes in adipokine protein expression due to GHD were highly dependent on the obesity phenotype. Lean GHD individuals (BMI approximately 23 kg/m(2)) had decreased protein levels for stem cell factor and epithelial growth factor, indicating a possible defect in adipocyte differentiation and proliferation. Decrease of vascular endothelial growth factor, stromal cell-derived factor, angiopoietin-2, and brain-derived neurotrophic factor advocated for attenuated angiogenesis and neurogenesis. Presence of obesity (BMI approximately 31 kg/m(2)) eliminated these inhibitory effects. However, adipose tissue expansion in GHD individuals was paralleled by an elevation of adipose tissue proinflammatory cytokines (IL-1beta, interferon-gamma) and chemoattractants (interferon-inducible T cell alpha-chemoattractant, monocyte chemotactic protein-2, monocyte chemotactic protein-3, eotaxin).

CONCLUSION

Our data demonstrate that GHD modulates adipokine and cytokine protein expression pattern, which might influence the adipose tissue growth and differentiation and predispose to tissue hypoxia, inflammation, and a defect in the whole-body insulin action.