European fitness landscape for children and adolescents: updated reference values, fitness maps and country rankings based on nearly 8 million test results from 34 countries gathered by the FitBack network.

OBJECTIVES: (1) To develop reference values for health-related fitness in European children and adolescents aged 6-18 years that are the foundation for the web-based, open-access and multilanguage fitness platform (FitBack); (2) to provide comparisons across European countries. METHODS: This study builds on a previous large fitness reference study in European youth by (1) widening the age demographic, (2) identifying the most recent and representative country-level data and (3) including national data from existing fitness surveillance and monitoring systems. We used the Assessing Levels of PHysical Activity and fitness at population level (ALPHA) test battery as it comprises tests with the highest test-retest reliability, criterion/construct validity and health-related predictive validity: the 20 m shuttle run (cardiorespiratory fitness); handgrip strength and standing long jump (muscular strength); and body height, body mass, body mass index and waist circumference (anthropometry). Percentile values were obtained using the generalised additive models for location, scale and shape method. RESULTS: A total of 7 966 693 test results from 34 countries (106 datasets) were used to develop sex-specific and age-specific percentile values. In addition, country-level rankings based on mean percentiles are provided for each fitness test, as well as an overall fitness ranking. Finally, an interactive fitness platform, including individual and group reporting and European fitness maps, is provided and freely available online (www.fitbackeurope.eu). CONCLUSION: This study discusses the major implications of fitness assessment in youth from health, educational and sport perspectives, and how the FitBack reference values and interactive web-based platform contribute to it. Fitness testing can be conducted in school and/or sport settings, and the interpreted results be integrated in the healthcare systems across Europe.

Adherence to the Mediterranean Diet and Successful aging in Greeks living in Greece and abroad: the epidemiological Mediterranean Islands Study (MEDIS).

Background: Whether older immigrant populations from the Mediterranean region, continue to follow the MD long after they immigrated is not known. Aim: Compare adherence to the MD and successful aging levels between Greeks living in Greece (GG) and Greeks living abroad (GA). Methods: Anthropometrical, clinical, psychological, sociodemographic, dietary and lifestyle parameters were assessed in a cross-sectional manner in a sample of 252 GG and 252 GA. Mediterranean Diet Score (MedDietScore range 0-55) was used to assess adherence to the MD. Successful aging was evaluated with the validated successful aging index (SAI range 0-10). Results: GA presented higher adherence to MD (p < 0.001); they were consuming significantly more cereals, legumes, vegetables, and fruits compared to GG. GG consumed significantly more dairy (3.8 ± 2.9 vs. 1.9 ± 2.2, p < 0.001) and potatoes (2.4 ± 1.6 vs. 1.9 ± 1.5, p < 0.001) compared to GA. Meat (p = 0.27), poultry (p = 0.72), fish (p = 0.68), olive oil (p = 0.16) and alcohol consumption (p = 0.05) were comparable between the two groups (all p's > 0.05). MedDietScore was positively associated with SAI among both groups after adjusting for possible confounders (0.041 ± 0.014, p = 0.003 GG and 0.153 ± 0.035, p < 0.001 GA). Also, legumes, cereals, fruits and vegetables were found to be beneficial for successful aging. Conclusion: Adherence to the MD is associated with higher levels of successful aging among people of the same genetic background living in different environments. However, traditional dietary habits are gradually abandoned in their native countries, when, at the same time, are considered cultural heritage and preserved accordingly among immigrants.

Recommended dairy intake is associated with healthy dietary habits, better physical fitness, less obesity and a healthier lifestyle profile in school age children.

This study aimed to identify the association of recommended dairy intake with several dietary habits, obesity, physical fitness (PF), physical activity (PA), screen time and sleep. Population data were derived from a health survey on a representative sample of 177 091 children aged 8-17 years. Dairy intake and dietary habits were evaluated using questionnaires (KIDMED index). Participants were characterised as 'dairy products consumers' based on whether they met current recommendations for milk or dairy consumption (e.g. if they consumed two yogurts and/or 40 g cheese and a cup of milk daily). Participants who did not consume the above-mentioned quantities were characterised as 'non-consumers.' Anthropometric and PF data were obtained by trained investigators. PA status, screen time and sleeping habits were assessed through self-completed questionnaires. Boys and girls consuming recommended dairy products were 25 % (95 % CI: 0·71, 0·79) and 43 % (95 % CI: 0·51, 0·64) less likely to have low performances in cardiorespiratory fitness tests, Participants from both sexes classified as dairy products consumers had lower odds of central obesity by 10 % (95 % CI: 0·86, 0·95), as compared with non-consumers. Moreover, recommended dairy products consumers had lower odds for insufficient sleep by 8 % (95 % CI: 0·89, 0·96) in boys and 14 % (95 % CI: 0·83-0·90) in girls, for inadequate PA levels by 15 % (95 % CI: 0·77, 0·93) in boys and 16 % (95 % CI: 0·76, 0·90) in girls and for increased screen time by 11 % (95 % CI: 0·83, 0·95) in boys and 9 % (95 % CI: 0·85, 0·97) in girls than no-consumers. In conclusion, recommended dairy intake is associated with less obesity, better PF and a healthier lifestyle profile.

The Association of Dietary Habits and Lifestyle Characteristics with Successful Aging among Older Greek Origin Individuals Living in France, Canada, and Greece: The Epidemiological Mediterranean Islands Study (MEDIS).

The aim of the present work was to investigate the association of dietary habits and lifestyle characteristics with successful aging among native Greeks and Greeks of Diaspora (Canada and France). During 2005-2019, 2,434 Greek men and women, living in Greece, in France, and in Canada, over 65 years of age were enrolled voluntarily in the study. Anthropometric, clinical and socio-demographic characteristics, dietary habits, and lifestyle parameters were derived through standard procedures, while successful aging was evaluated using the validated Successful Aging Index (SAI, range 0-10). The SAI of the overall sample was 2.8 ± 1.4. Greeks of Diaspora had higher SAI levels compared to their counterparts in Greece (p's < .001). However, there was no difference between Greeks of Canada and these of France (p > .05). Actually, Greeks of Diaspora had almost 1.9 units higher SAI compared to native Greeks (p < .001). Work and financial status, dietary and lifestyle behaviors (i.e., physical activity, smoking habits), and several clinical characteristics (i.e., history of hypertension and hypercholesterolemia) were statistically different between the three groups (all p's < .05). Greeks of Diaspora had higher SAI levels, probably because of their healthier lifestyle practices, which mainly depend on their traditions and cultural background of their homelands and living conditions in the host countries.

The association of animal and plant protein with successful ageing: a combined analysis of MEDIS and ATTICA epidemiological studies.

OBJECTIVE: The aim of the present study was to investigate the differences between the consumption of plant-based v. animal-based protein-rich diets on successful ageing, as well as to identify the optimal combination of dietary protein intake for facilitating successful ageing in people aged >50 years. DESIGN: A combined analysis was conducted in older adults of the ATTICA and MEDIS population-based cross-sectional studies. Anthropometrical, clinical and sociodemographic characteristics, lifestyle parameters, dietary habits and level of protein intake were derived through standard procedures. Successful ageing was evaluated using the validated Successful Aging Index (SAI) composed of ten health-related social, lifestyle and clinical characteristics. SETTING: Athens area and twenty Greek islands. PARTICIPANTS: A total of 3349 Greek women and men over 50 years old. RESULTS: Participants with high consumption of plant proteins were more likely to be male, physically active, with higher daily energy intake, higher adherence to the Mediterranean diet and higher level of SAI (P < 0·001). Participants with 'Low animal & High plant' and 'High animal & High plant' protein consumption had a 6 and 7 % higher SAI score, respectively, compared with the other participants (P < 0·001). In contrast, 'Low animal & Low plant' and 'High animal & Low plant' protein intake was negatively associated with SAI as compared to the combination of all other consumption categories (P < 0·02). CONCLUSIONS: The consumption of a plant-based protein-rich diet seems to be a beneficial nutritional choice that should be promoted and encouraged to older people since it may benefit both individual's health and prolong successful ageing.

Students Living in the Islands are Heavier and have Lower Fitness Levels Compared to their Mainland Counterparts; Results from the National Action for Children's Health (EYZHN) Program.

Few studies have examined variations in obesity by geographic location in youth and its relation with fitness levels. The present study investigated the association between geographic status (islands versus mainland), excess of body weight and fitness levels among 335.810 schoolchildren (male: 51.3%, 6-18 y, during the school year 2014-2015). Students' anthropometric parameters and fitness levels - accessed via the Euro-fit test - were measured by trained physical education teachers and evaluated according to published norms. Prevalence of overweight (23.0 Vs 21.8%) and obese (10.1 Vs 8.0%) was significantly higher for students living in the islands contrary to their mainland counterparts. A significant difference was also observed for centrally obese children (33.5 Vs 28.2%). Except for speed test .408), in all other four fitness tests, the students from the islands presented significantly lower performance (≤25th percentile of published age- and sex-specific normative values) versus their mainland counterparts. Boys and girls living in the islands had 48% and 37% increased odds of low physical fitness (as a total), respectively, compared to their mainland counterparts. Likewise, children living in islands presented increased odds of being overweight or obese by 19% and 15% in boys and girls, respectively, as compared to those living in the mainland. Increased general and abdominal adiposity have a direct negative impact on students' performance in Physical Fitness tests. Our data highlight the problem of excessive body weight that children living in rural areas, face.

Exclusive olive oil consumption was favorably associated with metabolic indices and lifestyle factors in schoolchildren.

BACKGROUND AND AIM: Olive oil consumption has been suggested to favorably impact children's health. The present study aimed to identify possible associations between exclusive olive oil consumption and metabolic indices and lifestyle factors. METHODS AND RESULTS: Cross-sectional, observational study. Population data derived from a health survey on a sample of 177 091 children aged 8-17 years. Olive oil consumption and dietary habits were evaluated using questionnaires (KIDMED index). Anthropometric and physical fitness measurements were obtained by trained investigators. Physical activity (PA) status, screen time and sleeping habits were assessed through self-completed questionnaires. Exclusive olive oil consumption decreased the odds of obesity and increased the odds of healthy cardiorespiratory fitness (CRF) by 15% (95% confidence interval (CI): 0.75-0.95) and 13% (95% CI: 1.04-1.22), respectively, after adjusting for several covariates. Moreover, exclusive olive oil consumption was associated with increased odds of having sufficient dietary habits (average/optimal adherence to the Mediterranean Diet) by almost four times (95% CI: 3.65-4.45) and decreased odds of insufficient sleep (<8-9 h/d) and increased screen time (>2 h/d) by 20% (95% CI: 0.73-0.87) and 40% (95% CI: 0.48-0.72), respectively. CONCLUSIONS: Exclusive olive oil consumption was associated with metabolic indices such as obesity and CRF and a healthy lifestyle profile. The exclusive consumption of olive oil as part of a balanced MD does seem to provide favorable health benefits and should be further promoted.

Associations of Maternal Prepregnancy Body Mass Index and Gestational Weight Gain With Physical Fitness in Childhood.

PURPOSE: To investigate the potential associations of maternal prepregnancy body mass index (mppBMI) and gestational weight gain (GWG) with physical fitness in children. METHODS: A random sample of 5125 children and their mothers was evaluated. The mothers provided data contained in their medical booklets and pregnancy ultrasound records. The data from 5 physical fitness tests (eg, 20-m shuttle run, 30-m sprint, vertical jump, standing long jump, and small ball throw) were used to assess children's cardiorespiratory fitness, speed, explosive power, and lower and upper body strength, respectively. RESULTS: MppBMI was inversely associated with cardiorespiratory fitness (b = -0.02), lower body strength (b = -1.01), upper body strength (b = -0.07), and speed (b = 0.04). Also, GWG was unfavorably associated with cardiorespiratory fitness (b = -0.02), lower body strength (b = -1.12), upper body strength (b = -0.03), and speed (b = 0.03), after adjusting for sex, birth weight, and children's BMI (all P values < .05). Children of mothers with an mppBMI ≥ 25 kg/m2 and excess GWG had almost 30% and 20% increased odds for low performances in physical fitness tests than those of mothers with an mppBMI < 25 kg/m2 and adequate GWG, respectively. CONCLUSIONS: Antenatal factors such as increased mppBMI and excess GWG could play an unfavorable role in the future health of the offspring.

Screen time and its effect on dietary habits and lifestyle among schoolchildren.

OBJECTIVE: The aim of the study was to determine the associations between recreational screen time and dietary habits and lifestyle factors in a representative sample of schoolchildren. METHODS: Observational, cross-sectional study data were derived from 177,091 children aged 8 to 17 years participating in a health survey. Recreational screen time, physical activity (PA), and sleeping hours were assessed through self-completed questionnaires. Dietary habits were evaluated via the Mediterranean Diet Quality Index for children and adolescents (KIDMED) test. Anthropometric and physical fitness (PF) estimations were obtained by trained investigators. RESULTS: Binary logistic regression comparisons between screen time levels (e.g. < 2 vs. ≥ 2 - < 3 h/d, < 2 vs. ≥ 3 - < 4 h/d and < 2 vs. ≥ 4 h/d) and dietary habits showed that the longer the screen time the increased the odds of unhealthy dietary habits such as skipping breakfast, consuming fast food frequently, and eating sweets frequently, and the decreased the odds of healthy dietary habits such as consuming a second fruit every day, consuming fresh or cooked vegetables or/and fish regularly, in both genders, after adjusting for several covariates. Furthermore, the longer the screen time the increased the odds of total and central obesity, insufficient sleep (< 8-9 h/d), and inadequate PA, and the decreased the odds of healthy PF. CONCLUSIONS: The longer the screen time the unhealthier dietary habits and lifestyle profile among schoolchildren, after adjusting for several covariates.

From Mediterranean diet to Mediterranean lifestyle: a narrative review.

OBJECTIVE: To summarize the recent scientific evidence regarding the wellness-promoting capacity of the Mediterranean lifestyle (ML), with a special focus on physical, social and environmental wellness. DESIGN: Narrative review of English-language publications in PubMed, Scopus and Embase, from 1 January 2010 to 31 October 2018. SETTING: Prospective cohort studies, interventional studies, meta-analyses and reviews of those investigating the effect of at least one component of the ML on wellness parameters. PARTICIPANTS: General population. RESULTS: Although an explicit definition of ML is missing, compliance with various combinations of its components improves metabolic health and protects against or ameliorates disease state. However, there is heterogeneity in the healthy behaviours that the ML-focused studies include in their design and the way these are assessed. Also, despite that features of the ML could contribute to other wellness dimensions, there are no studies exploring the effect this healthy lifestyle could confer to them. CONCLUSIONS: Chronic lifestyle diseases are of multifactorial aetiology and they warrant multifaceted approaches targeting the general way of living. ML, if thoroughly evaluated, can provide a valuable tool to holistically promote health and wellness.

The Association between Green and Black Tea Consumption on Successful Aging: A Combined Analysis of the ATTICA and MEDiterranean ISlands (MEDIS) Epidemiological Studies.

Tea is one of the most-widely consumed beverages in the world with a number of different beneficial health effects, mainly ascribed to the polyphenolic content of the tea catechins. The aim of this study was to examine the consumption of green, black, or no tea, in relation to the previously validated successful ageing index (SAI; higher values "healthier" ageing) in a combined analysis of adults aged >50 years old from the ATTICA (n = 1128 adults from Athens, Greece metropolitan area) and the MEDiterranean Islands Study (MEDIS) (n = 2221 adults from various Greek island and Mani) studies. After adjusting for age, sex, smoking, and coffee consumption, green tea was positively associated with SAI (b ± SE: 0.225 ± 0.055, p < 0.001), while black tea was negatively associated with SAI (unstandardized b coefficient ± Standard error: -0.807 ± 0.054, p < 0.001). Green tea (vs black tea) consumption, had higher odds of a SAI of over 3.58 out of 10 (OR: 1.77, 95% CI: 1.38-2.28). Green tea consumption was also associated with higher levels of physical activity (p < 0.001) and reduced likelihood of hypertension (p = 0.006) compared with black tea. Two possible mechanisms are that green tea possesses high levels of catechins such as (-)-epigallocatechin 3-gallate and l-theanine compared with black tea. Therefore, the present analysis supports both the role of green tea constituents in successful ageing, as well as its role as an important component of an overall healthy diet in adults aged 50 years and over from these two epidemiological studies.

Anti-Inflammatory Nutrition and Successful Ageing in Elderly Individuals: The Multinational MEDIS Study.

BACKGROUND: The role of diet and inflammation in successful ageing is not transparent, and as such, is still being investigated. The aim of the present work was to evaluate the inflammatory potential of dietary habits in the successful ageing of a random sample of older adults living in the Mediterranean basin and who participated in the MEDIS (MEDiterranean ISlands) study. METHODS: During 2005-2016, 3,128 older adults (aged 65-100 years) from 24 Mediterranean islands and the rural Mani region (Peloponnesus) of Greece were enrolled in the study. A multidimensional successful ageing index consisting of 10 components was employed. A validated and reproducible Food Frequency Questionnaire (FFQ) was used to evaluate the dietary habits of the older adults. A nutrition anti-inflammatory (NAI) score based on the participants' specific dietary habits was assessed. RESULTS: Participants with high NAI scores (proinflammatory nutrition) had a higher prevalence of hypercholesterolemia and lower levels of successful ageing. After adjusting for several confounders, the NAI score was associated with successful ageing (-0.03, 95% CI -0.5 to -0.006). Stratified analysis by gender and advanced age revealed heterogeneity in the NAI score, predicting successful ageing. CONCLUSIONS: The inflammatory potential of nutrition was reported as an important factor for successful ageing, suggesting that further research is needed on the role of anti- and proinflammatory dietary habits in healthy and successful ageing.

Association between fast-food consumption and lifestyle characteristics in Greek children and adolescents; results from the EYZHN (National Action for Children's Health) programme.

OBJECTIVE: To examine the prevalence of fast-food consumption and the association between fast food and lifestyle factors in a representative sample of children and adolescents. DESIGN: Cross-sectional, observational study. Fast-food consumption and dietary habits were evaluated using questionnaires (KIDMED index). Anthropometric and physical fitness measurements were obtained by trained investigators. Physical activity (PA) status, sedentary activities and sleeping habits were assessed through self-completed questionnaires. SETTING: Greece. SUBJECTS: Population data derived from a school-based health survey (EYZHN programme) carried out in 2015 on 177 091 (51 % boys) children aged 8-17 years. RESULTS: A greater proportion of boys v. girls (23·3 v. 15·7 %, P1 time/week. Frequent fast-food consumption was strongly correlated with unhealthy dietary habits such as skipping breakfast and consuming sweets/candy regularly. Adjusting for several covariates, insufficient dietary habits, insufficient (<8-9 h/d) sleep, inadequate PA levels and increased screen time increased the odds (95 % CI) of being a frequent fast-food consumer by 77 % (0·218, 0·234), 30 % (1·270, 1·338), 94 % (1·887, 1·995) and 32 % (1·287, 1·357), respectively. Being overweight/obese or centrally obese did not correlate with frequency of fast-food consumption. CONCLUSIONS: Frequent fast-food consumption was associated with an unhealthy lifestyle profile among children and adolescents. The findings support the development of interventions to help children adopt healthier dietary habits.

Validity of Predictive Equations for Resting Energy Expenditure in Greek Adults.

AIM: To examine the validity of published resting energy expenditure (REE) equations in Greek adults, and if indicated, develop new cohort-specific predictive REE equations. METHODS: Indirect calorimetry and anthropometric data were obtained from 226 adult volunteers of diverse age groups and body mass index ranges (18-60 years, 16.6-67.7 kg·m-2). Measured REE was compared to preexisting prediction equations via correlation, regression, and Bland-Altman analysis. Then, cohort-specific REE equations were developed using curve estimation and nonlinear regression. To reduce type I error, presently derived equations were validated by splitting the sample into a training and validation group. RESULTS: Preexisting equations over-predicted in-cohort REE. Equations by Livigston and Kohlstadt were most accurate at the individual level (63% accuracy), while formulas by Owen and collaborators elicited highest accuracy at the group level (-1.8% bias). Bland-Altman analysis showed proportional bias for most equations. Currently developed equations showed highest overall accuracy with 70% at the individual and group level (1.0% bias), with small differences between measured and predicted REE values (mean, 95% CI 36 [-15 to 88] kcal·day-1). CONCLUSION: Data indicate currently developed equations to be the most accurate and valid for estimating REE in Greek adults. Further studies should examine the developed equations in an independent sample.

Similar Mediterranean diet adherence but greater central adiposity is observed among Greek diaspora adolescents living in Istanbul, compared to Athens.

OBJECTIVE: The aim of this case-control study was to compare Mediterranean diet (MD) adherence and anthropometry between Greek diaspora adolescents living in Istanbul and Greek adolescents, inhabitants of Athens. DESIGN: A total of 206 adolescents (103 from each site), aged 10.0-19.0 years old, all of Greek origin, were recruited from schools in Athens and minority schools in Istanbul, for the present case-control study. Participants at each site were age and sex-matched. Anthropometric measurements were performed, and diet adherence was assessed with the KIDMED score. RESULTS: Breakfast skipping, decreased dairy and increased commercially baked good/pastries consumption for breakfast, fast-food intake and consumption of several sweets each day was more prevalent in Istanbul, but, on the other hand, students from Athens reported eating fewer fruit, vegetables and nuts. The adoption of unhealthy eating habits in each site was counterbalanced by a more 'healthy' dietary element, resulting in an overall similar MD adherence between both sites. Additionally, although weight status was indifferent between the two cities, higher rates of abdominal obesity were recorded in Istanbul, when the weight-to-height ratio was used for diagnosis. CONCLUSIONS: Differences in several domains of the KIDMED score were recorded among cities, possibly as results of food availability and prices. However, MD adherence and weight status appeared similar, indicating that the dietary transition and acculturation experienced by the remnants is actually very slow and minimal during the 93 years since population exchange.

Progressive Dehydration in Junior Laser Class Sailors During World Championship.

The purpose of this article is to assess the hydration status of elite young sailing athletes during World Championship competition. Twelve young, elite, male, Laser Class sailors (age: 15.8 ± 1.1 y, height: 1.74 ± 0.1 m, weight: 65.1 ± 1.5 kg, body fat: 12.5 ± 3.1%, training experience: 7.0 ± 1.2 y) participated in this descriptive study. After three-day baseline bodyweight measurements, hydration status was assessed via pre- and post-race body weights, urine-specific gravity, and thirst ratings via a visual analog scale during four consecutive days of racing. Measurements and data collection took place at the same time each racing day, with mean environmental temperature, humidity, and wind speed at 23.0 ± 0.8°C, 64-70%, and 9 ± 1 knots, respectively. Average racing time was 130 ± 9 min. Body weight was significantly decreased following each race-day as compared to prerace values (Day 1: -1.1 ± 0.2, Day 2: -2.5 ± 0.1, Day 3: -2.8 ± 0.1, and Day 4: -3.0 ± 0.1% of body weight; p < 0.05). The participants exhibited dehydration of -2.9 ± 0.2 and -5.8 ± 0.2% of body weight before and after the fourth racing day as compared to the three-day baseline body weight. Urine-specific gravity (pre-post → Day 1: 1.014-1.017; Day 2: 1.019-1.024; Day 3: 1.021-1.026; Day 4: 1.022-1.027) and thirst (pre-post → Day 1: 2.0-5.2; Day 2: 3.2-5.5; Day 3: 3.7-5.7; Day 4: 3.8-6.8) were also progressively and significantly elevated throughout the four days of competition. The data revealed progressive dehydration throughout four consecutive days of racing as indicated by decreased body weight, elevated urine concentration, and high thirst.

The metabolic stress response to burn trauma: current understanding and therapies.

Major burns provoke a profound stress response, which is unrivalled in terms of its magnitude and duration. Evidence suggests that the pathophysiological stress response to severe burn trauma persists for several years after injury. Thus, there is a pressing need for novel strategies that mitigate this response and restore normal metabolic function in patients with burns. This is the first in a Series of three papers about the care of people with burns. In this paper, we review the current knowledge of the stress response to burn trauma, with a focus on hypermetabolism, muscle wasting, and stress-induced diabetes. We highlight recent developments and important knowledge gaps that need to be pursued to develop novel therapeutic strategies to improve outcomes in burn survivors.

The effect of hypohydration on endothelial function in young healthy adults.

PURPOSE: Hypohydration has been suggested as a predisposing factor for several pathologies including cardiovascular diseases (CVD). While CVD are the leading cause of death worldwide, no study has investigated whether acute hypohydration affects endothelial function and cardiovascular function. METHODS: Ten young, healthy males participated in this crossover study (age: 24.3 ± 2.3 year; weight: 80.8 ± 5.3 kg; BMI: 24.3 ± 0.4 kg m-2). Each subject completed two measurements of endothelial function by flow-mediated dilation (FMD) in euhydrated and hypohydrated state separated by 24 h. Following baseline assessment of hydration status and FMD, the subjects completed 100 min of low-intensity intermittent walking exercise to achieve hypohydration of -2 % of individual body mass. For the rest of the day, a standardized, low water content diet was provided. The following morning, hydration markers and endothelial function were recorded. RESULTS: Hypohydration by -1.9 ± 0.1 % of body mass resulted in decreased plasma volume by -3.5 ± 1.8 % and increased plasma osmolality by 9 ± 2 mmol kg-1 (P < 0.001). FMD as a response to hypohydration decreased by -26.8 ± 3.9 % (P < 0.05). CONCLUSION: The data suggested that a small degree of hypohydration induced by moderate exercise and fluid restriction significantly impaired endothelial function.

Satellite cell activation and apoptosis in skeletal muscle from severely burned children.

KEY POINTS: Severe burns result in profound skeletal muscle atrophy that hampers recovery. The activity of skeletal muscle stem cells, satellite cells, acutely following a severe burn is unknown and may contribute to the recovery of lean muscle. Severe burn injury induces skeletal muscle regeneration and myonuclear apoptosis. Satellite cells undergo concurrent apoptosis and activation acutely following a burn, with a net reduction in satellite cell content compared to healthy controls. The activation and apoptosis of satellite cells probably impacts the recovery of lean tissue following a severe burn, contributing to prolonged frailty in burn survivors. ABSTRACT: Severe burns result in profound skeletal muscle atrophy; persistent muscle loss and weakness are major complications that hamper recovery from burn injury. Many factors contribute to the erosion of muscle mass following burn trauma and we propose that an impaired muscle satellite cell response is key in the aetiology of burn-induced cachexia. Muscle biopsies from the m. vastus lateralis were obtained from 12 male pediatric burn patients (>30% total body surface area burn) and 12 young, healthy male subjects. Satellite cell content, activation and apoptosis were determined via immunohistochemistry, as were muscle fibre regeneration and myonuclear apoptosis. Embryonic myosin heavy chain expression and central nucleation, indices of skeletal muscle regeneration, were elevated in burn patients (P < 0.05). Myonuclear apoptosis, quantified by TUNEL positive myonuclei and cleaved caspase-3 positive myonuclei, was also elevated in burn patients (P < 0.05). Satellite cell content was reduced in burn patients, with approximately 20% of satellite cells positive for TUNEL staining, indicating DNA damage associated with apoptosis (P < 0.05). Additionally, a significant percentage of satellite cells in burn patients expressed Ki67, a marker for cellular proliferation (P < 0.05). Satellite cell activation was also observed in burn patients with increased expression of MyoD compared to healthy controls (P < 0.05). Robust skeletal muscle atrophy occurs after burn injury, even in muscles located distally to the site of injury. The activation and apoptosis of satellite cells probably impacts the recovery of lean tissue following a severe burn, contributing to prolonged frailty in burn survivors.

Hypermetabolism and hypercatabolism of skeletal muscle accompany mitochondrial stress following severe burn trauma.

Burn trauma results in prolonged hypermetabolism and skeletal muscle wasting. How hypermetabolism contributes to muscle wasting in burn patients remains unknown. We hypothesized that oxidative stress, cytosolic protein degradation, and mitochondrial stress as a result of hypermetabolism contribute to muscle cachexia postburn. Patients (n = 14) with burns covering >30% of their total body surface area were studied. Controls (n = 13) were young healthy adults. We found that burn patients were profoundly hypermetabolic at both the skeletal muscle and systemic levels, indicating increased oxygen consumption by mitochondria. In skeletal muscle of burn patients, concurrent activation of mTORC1 signaling and elevation in the fractional synthetic rate paralleled increased levels of proteasomes and elevated fractional breakdown rate. Burn patients had greater levels of oxidative stress markers as well as higher expression of mtUPR-related genes and proteins, suggesting that burns increased mitochondrial stress and protein damage. Indeed, upregulation of cytoprotective genes suggests hypermetabolism-induced oxidative stress postburn. In parallel to mtUPR activation postburn, mitochondrial-specific proteases (LONP1 and CLPP) and mitochondrial translocases (TIM23, TIM17B, and TOM40) were upregulated, suggesting increased mitochondrial protein degradation and transport of preprotein, respectively. Our data demonstrate that proteolysis occurs in both the cytosolic and mitochondrial compartments of skeletal muscle in severely burned patients. Increased mitochondrial protein turnover may be associated with increased protein damage due to hypermetabolism-induced oxidative stress and activation of mtUPR. Our results suggest a novel role for the mitochondria in burn-induced cachexia.