Associations Between Eating Speed, Diet Quality, Adiposity, and Cardiometabolic Risk Factors.

OBJECTIVE: To assess the associations between eating speed, adiposity, cardiometabolic risk factors, and diet quality in a cohort of Spanish preschool-children. STUDY DESIGN: A cross-sectional study in 1371 preschool age children (49% girls; mean age, 4.8 ± 1.0 years) from the Childhood Obesity Risk Assessment Longitudinal Study (CORALS) cohort was conducted. After exclusions, 956 participants were included in the analyses. The eating speed was estimated by summing the total minutes used in each of the 3 main meals and then categorized into slow, moderate, or fast. Multiple linear and logistic regression models were fitted to assess the ß-coefficient, or OR and 95% CI, between eating speed and body mass index, waist circumference, fat mass index (FMI), blood pressure, fasting plasma glucose, and lipid profile. RESULTS: Compared with participants in the slow-eating category, those in the fast-eating category had a higher prevalence risk of overweight/obesity (OR, 2.9; 95% CI, 1.8-4.4; P < .01); larger waist circumference (ß, 2.6 cm; 95% CI, 1.5-3.8 cm); and greater FMI (ß, 0.3 kg/m2; 95% CI, 0.1-0.5 kg/m2), systolic blood pressure (ß, 2.8 mmHg; 95% CI, 0.6-4.9 mmHg), and fasting plasma glucose levels (ß, 2.7 mg/dL, 95% CI, 1.2-4.2 mg/dL) but lower adherence to the Mediterranean diet (ß, -0.5 points; 95% CI, -0.9 to -0.1 points). CONCLUSIONS: Eating fast is associated with higher adiposity, certain cardiometabolic risk factors, and lower adherence to a Mediterranean diet. Further long-term and interventional studies are warranted to confirm these associations.

Methods recently used for the assessment of physical activity in children and adolescents.

PURPOSE OF REVIEW: The aim of this review is to summarize recent evidences and advances on the implementation and the use of new tools to assessing physical activity (PA) in children. RECENT FINDINGS: Technological advances provide, increasingly, new objective methods for the evaluation of PA in children. In addition to accelerometry, there are other objective methods for assessing PA in children such as new wearable monitoring and activity bracelets, smartphone and recording software applications, Global Positioning System or Inertial Sensors Devices. SUMMARY: Doubly labeled water and calorimetry are reference methods to assessing PA but with limitations of use. Accelerometry is an accurate method for measuring sedentary behavior and PA levels in children. In fact, it is a real alternative reference method for the validation of methods and tools of assessing PA. However, there is still no consensus about the most appropriate approach to analyze the duration and intensity of PA in children. Therefore, the implementation of other alternative objective methods, as well as complementation with PA questionnaires, can provide a more precise evaluation of different patterns and behaviors related with sedentarism and PA.

[Study of obesity in a rural children population and its relationship with anthropometric variables]. / Estudio de la obesidad en una población infantil rural y su relación con variables antropométricas.

GOALS: To know the prevalence of obesity in primary and secondary school students, and to evaluate the diagnostic accuracy of anthropometric variables for its detection. DESIGN: Cross-sectional study. LOCATION: Rural area of Córdoba. In the year 2014. PARTICIPANTS: Student population. A stratified sampling was performed according to age, gender and educational centers. A total of 323 students from 6 to 16 years were included in the study, all parents had signed informed consent. MAIN MEASUREMENTS: The prevalence of obesity was determined and sociodemographic, anthropometric, physical condition and dietary predictor variables were collected. A binary logistic regression was performed determining crude and adjusted Odds Ratio (OR) values, ROC curves were obtained and cut-off values were determined, calculating the sensitivity, specificity and Youden index. RESULTS: The prevalence of overweight and obesity was 26.2% and 22.3%, respectively. Only 15.2% of school children had an optimal Mediterranean diet. The waist-height ratio (WtHR) was the predictive variable with the highest adjusted OR 7.1 (4.3-11.6) and the largest area under the curve 0.954 (0.928-0.979), from a global cut-off value to discriminate obesity of 0.507. This gave a sensitivity of 90% and specificity of 87.2%. CONCLUSIONS: The high prevalence of obesity, the low-medium adherence to the Mediterranean diet and the low physical fitness make this population a priority target for the prevention of future cardiovascular events. The WtHR has been the best anthropometric predictor of obesity, recommending its use for the diagnosis of obesity in children at the expense of body mass index.

Physical Activity Level Using Doubly-Labeled Water in Relation to Body Composition and Physical Fitness in Preschoolers.

Background and objectives: There is a lack of studies investigating associations of physical activity level (PAL) and activity energy expenditure (AEE) using the doubly-labeled water (DLW) method with body composition and physical fitness in young children. Thus, we aimed to examine cross-sectional associations of PAL and AEE with body composition indices and physical fitness components in Swedish preschool children. Materials and methods: PAL was calculated as total energy expenditure measured using DLW divided by the predicted basal metabolic rate in 40 children aged 5.5 (standard deviation 0.2) years. AEE was calculated as total energy expenditure minus basal metabolic rate and the thermic effect of food, and divided by fat-free mass. Body composition was assessed using the 3-component model by combining measurements based on isotope dilution and air-displacement plethysmography. Physical fitness (muscular strength, motor fitness, and cardiorespiratory fitness) was evaluated using the PREFIT test battery. Multiple linear regression models were conducted. Results: PAL and AEE were negatively associated with body mass index, percent body fat, and fat mass index (PAL: standardized ß -0.35, -0.41, and -0.45, all p < 0.036; AEE: standardized ß -0.44, -0.44, and -0.47, all p < 0.006, respectively). Furthermore, PAL and AEE were positively associated with the standing long jump test (PAL: standardized ß 0.37, p = 0.017; AEE: standardized ß 0.38, p = 0.014). There were no statistically significant associations found regarding PAL or AEE with fat-free mass index or any other physical fitness test. Conclusions: Greater PAL and AEE at the age 5.5 were significantly associated with body fatness and improved lower-body muscular strength. Therefore, increasing physical activity, and thus energy expenditure, at young ages may be beneficial for preventing overweight/obesity. However, further studies with larger sample sizes are needed to confirm the results.

A Clustering Study of Dietary Patterns and Physical Activity among Workers of the Uruguayan State Electrical Company.

Recent studies have shown that certain nutrients, specific food groups, or general dietary patterns (DPs) can promote health and prevent noncommunicable chronic diseases (NCCDs). Both developed and developing countries experience a high prevalence of NCCDs due to poor lifestyle habits, DPs, and low physical activity levels. This study aims to examine the dietary, physical activity, sociodemographic, and lifestyle patterns of Uruguayan State Electrical Company workers (the IN-UTE study). A total of 2194 workers participated in the study, providing information about their sociodemographics, lifestyles, and dietary habits through different questionnaires. To identify DPs from 16 food groups, principal component analysis (PCA) was performed. A hierarchical cluster algorithm was used to combine food groups and sociodemographic/lifestyle variables. Four DPs were extracted from the data; the first DP was related to the intake of energy-dense foods, the second DP to the characteristics of the job, the third DP to a Mediterranean-style diet, and the fourth DP to age and body mass index. In addition, cluster analysis involving a larger number of lifestyle variables produced similar results to the PCA. Lifestyle and sociodemographic factors, including night work, working outside, and moderate and intense PA, were significantly correlated with the dietary clusters, suggesting that working conditions, socioeconomic status, and PA may play an important role in determining DPs to some extent. Accordingly, these findings should be used to design lifestyle interventions to reverse the appearance of unhealthy DPs in the UTE population.

Non-traditional markers of metabolic risk in prepubertal children with different levels of cardiorespiratory fitness.

OBJECTIVE: To assess classical and non-classical metabolic risk biomarkers in prepubertal children with different levels of cardiorespiratory fitness (CRF). DESIGN: CRF was assessed by the 20 m shuttle run test. To estimate physical activity, participants were observed while engaged in an after-school programme. Additionally, a short test based on a validated questionnaire was used to obtain information about physical activity practice and sedentary habits. Anthropometric parameters, blood pressure, and classical and non-traditional metabolic risk biomarkers--plasma lipid profile, glucose and insulin, homeostasis model assessment-insulin resistance index (HOMA-IR), plasma uric acid, transaminases and C-reactive protein (CRP)--were measured. SETTING: The study was conducted in local elementary schools in Córdoba, Spain. SUBJECTS: One hundred and forty-one healthy children (eighty-eight boys, fifty-three girls) aged 7-12 years, in Tanner stage I, were recruited. They were divided into two groups after they performed the 20 m shuttle run test: equal or higher cardiovascular fitness (EHCF) group and low cardiovascular fitness (LCF) group. RESULTS: The LCF group displayed significantly higher TAG (P = 0.004) and lower HDL cholesterol levels (P = 0.001), as well as significantly lower values for the non-traditional lipid marker apo-A1 (P = 0.001) compared with the EHCF group. The LCF children displayed higher plasma glucose (P = 0.003) and insulin levels, higher HOMA-IR scores (P < 0.001) and higher plasma uric acid and CRP levels (P < 0.05). After adjustment for BMI, age and sex, no statistically significant differences were found between groups for the biomarkers analysed. CONCLUSIONS: The study provides new information to understand the role not only of weight status but also of the level of CRF on the metabolic health profile of prepubertal children.

Fitness Levels and Gender Are Related With the Response of Plasma Adipokines and Inflammatory Cytokines in Prepubertal Children.

Background and Aim: Changes in adipokines have been related with the development of metabolic syndrome, frequently associated with obesity, and other risk factors. Fitness seems to promote a healthy cardiovascular status and could be a protector factor, just from childhood. Therefore, the present study aimed to evaluate the relationship between fitness levels with plasma adipokines and inflammatory biomarkers in prepubertal children. Methods: One hundred and thirty-seven healthy normal-weight prepubertal children were recruited from local schools and divided after performing the fitness tests, into two groups according to fitness level-low cardiovascular fitness group (LF) and equal or higher cardiovascular fitness group (HF). Anthropometric variables, blood pressure (BP) and plasma insulin, and leptin, resistin, adiponectin, tumor necrosis factor-alpha, hepatic growth factor, interleukin (IL)-8, monocyte chemoattractant protein-1, nerve growth factor (NGF), and plasminogen activator inhibitor-1 (PAI-1) were measured fasting in both groups to be compared. Univariate analysis of variance, comparative analysis, binary logistic regression, stepwise linear regression, and principal component analysis were conducted to evaluate the association between fitness, BMI, gender, and the biochemical parameters. Results: Girls and boys with HF presented lower waist circumference Z-score, BMI Z-score, systolic BP (only boys) as well as lower levels of leptin and NGF compared with their respective LF group. Regarding the association between variables, fitness showed an inverse relationship with BMI Z-score, leptin, PAI-1, HOMA-IR, resistin, IL-8, and NGF. Conclusion: An adequate level of fitness seems to protect against risk factors related to low-grade inflammation and altered adipokines that are related to the onset of obesity just from the prepubertal stage.

Beetroot Juice Produces Changes in Heart Rate Variability and Reduces Internal Load during Resistance Training in Men: A Randomized Double-Blind Crossover.

Beetroot juice (BJ) has been used as a sport supplement, improving performance in resistance training (RT). However, its effect on the modulation of the autonomic nervous system has not yet been widely studied. Therefore, the objective of this randomized double-blind crossover study was to assess the effect of acute BJ supplementation compared to placebo in blood pressure (BP), heart rate (HR), heart rate variability (HRV) and internal load during RT measure as Root Mean Square of the Successive Differences between adjacent RR intervals Slope (RMSSD and RMSSD-Slope, respectively). Eleven men performed an incremental RT test (three sets at 60%, 70% and 80% of their repetition maximum) composed by back squat and bench press with. HR, HRV and RMSSD-Slope were measured during and post exercise. As the main results, RMSSD during exercise decrease in the BJ group compared to placebo (p = 0.023; ES = 0.999), there were no differences in RMSSD post-exercise, and there were differences in RMSSD-Slope between groups in favor of the BJ group (p = 0.025; ES = 1.104) with a lower internal load. In conclusion, BJ supplementation seems to be a valuable tool for the reduction in the internal load of exercise during RT measured as RMSSD-Slope while enhancing performance.

Prepubertal Children With Metabolically Healthy Obesity or Overweight Are More Active Than Their Metabolically Unhealthy Peers Irrespective of Weight Status: GENOBOX Study.

Background and Aim: The association of a metabolically healthy status with the practice of physical activity (PA) remains unclear. Sedentarism and low PA have been linked to increased cardiometabolic risk. The aim of this study was to evaluate the PA levels in metabolically healthy (MH) or unhealthy (MU) prepubertal children with or without overweight/obesity. Methods: A total 275 children (144 boys) with 9 ± 2 years old were selected for the GENOBOX study. PA times and intensities were evaluated by accelerometry, and anthropometry, blood pressure, and blood biochemical markers were analyzed. Children were considered to have normal weight or obesity, and further classified as MH or MU upon fulfillment of the considered metabolic criteria. Results: Classification resulted in 119 MH children (21% with overweight/obesity, referred to as MHO) and 156 MU children (47% with overweight/obesity, referred to as MUO). Regarding metabolic profile, MHO showed lower blood pressure levels, both systolic and diastolic and biochemical markers levels, such as glucose, Homeostatic Model Assessment of Insulin Resistance, triglycerides and higher HDL-c levels than MUO (P < 0.001). In addition, MHO children spent more time in PA of moderate intensity compared with MUO children. In relation to vigorous PA, MH normal weight (MHN) children showed higher levels than MUO children. Considering sex, boys spent more time engaged in moderate, vigorous, and moderate-vigorous (MV) PA than girls, and the number of boys in the MH group was also higher. Conclusion: Prepubertal MHO children are less sedentary, more active, and have better metabolic profiles than their MUO peers. However, all children, especially girls, should increase their PA engagement, both in terms of time and intensity because PA appears to be beneficial for metabolic health status itself.

Evaluation of Sedentary Behavior and Physical Activity Levels Using Different Accelerometry Protocols in Children from the GENOBOX Study.

BACKGROUND: Physical activity (PA) has acquired a significant relevance due to the health benefits associated with its practice. Accelerometers are an effective tool to assess PA; however, the diversity of cut-off points used to define different PA intensities through accelerometry could interfere in the interpretation of the findings among studies. OBJECTIVES: The present study aimed to examine the sedentary behavior (SB) and physical activity (PA) levels in children using six selected accelerometry protocols based on diverse cut-off points. METHODS: Clinical examination, anthropometric measurements, and PA evaluation by accelerometry were assessed in 543 selected children (10 ± 2.4 years old) from the Spanish GENOBOX study. The ActiLife data scoring program was used to determine daily min spent in SB, and light, moderate, vigorous and moderate-vigorous PA using six validated accelerometry protocols differing in their cut-off points. RESULTS: Very different estimations for SB and PA intensity levels were found in children, independently of the non-wear-time algorithm selected, and considering puberty stages, age and body mass index. The time spent in daily SB varied from 471 to 663.7 min, PA ranged from 141 to 301.6 min, and the moderate-vigorous PA was reported between 20.7 and 180.2 min. CONCLUSION: The choice of a particular accelerometry protocol considering these factors is important to evaluate SB or PA intensities to suit the characteristics of the sample researched. It seems necessary to establish future lines of research that include different analytical approaches to measure SB and PA by accelerometry based on standardized and validated methodology.

Association of Diet, Physical Activity Guidelines and Cardiometabolic Risk Markers in Children.

The aim was to identify different dietary and physical activity (PA) patterns in 5- to 14-year-old children with a high prevalence of overweight and obesity using cluster analysis based on their adherence to the Spanish Society of Community Nutrition dietary guidelines and levels of PA, and to determine their associations with age, sex, body composition, and cardiometabolic risk markers. In 549 children, hierarchical cluster analysis was used to identify subgroups with similar adherence to dietary recommendations and level of PA. Three clusters were identified: Cluster 1, with the lowest level of vigorous PA and adherence to dietary recommendations; Cluster 2, with the lowest levels of moderate and vigorous PA and the highest adherence to dietary recommendations; and Cluster 3, with the highest level of PA, especially vigorous PA and a medium level adherence to dietary recommendations. Cluster 3 had lower total body fat and higher lean body mass percentages than Cluster 2. Cluster 2 had lower high-density lipoprotein cholesterol and higher low-density lipoprotein cholesterol levels than Cluster 1. The results from our study suggest that it is important to consider adherence to PA recommendations together with adherence to dietary guidelines to understand patterns of obesogenic habits in pediatric populations with high prevalence of overweight and obesity.

Relationship between Physical Activity, Oxidative Stress, and Total Plasma Antioxidant Capacity in Spanish Children from the GENOBOX Study.

The World Health Organization has recommended performing at least 60 min a day of moderate-to-vigorous physical activity (MVPA) and reducing sedentarism in children and adolescents to offer significant health benefits and mitigate health risks. Physical fitness and sports practice seem to improve oxidative stress (OS) status during childhood. However, to our knowledge, there are no data regarding the influence of objectively-measured physical activity (PA) and sedentarism on OS status in children and adolescents. The present study aimed to evaluate the influence of moderate and vigorous PA and sedentarism on OS and plasma total antioxidant capacity (TAC) in a selected Spanish population of 216 children and adolescents from the GENOBOX study. PA (light, moderate, and vigorous) and sedentarism (i.e., sedentary time (ST)) were measured by accelerometry. A Physical Activity-Sedentarism Score (PASS) was developed integrating moderate and vigorous PA and ST levels. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and isoprostane F2α (F2-IsoPs), as markers of OS, were determined by ELISA; and TAC was estimated by colorimetry using an antioxidant kit. A higher PASS was associated with lower plasma TAC and urinary 8-OHdG and F2-IsoPs, showing a better redox profile. Reduced OS markers (8-OHdG and F2-IsoPs) in children with higher PASS may diminish the need of maintaining high concentrations of antioxidants in plasma during rest to achieve redox homeostasis.

Evaluation of Physical Activity and Lifestyle Interventions Focused on School Children with Obesity Using Accelerometry: A Systematic Review and Meta-Analysis.

Despite the existence of global recommendations for physical activity and lifestyle to avoid childhood obesity, there are no specific recommendations for school-age children. The aim of this meta-analysis was to measure the effects of current interventions with a physical activity component on body mass index (BMI) Z-score and on the moderate and vigorous physical activity (MVPA) time, measured by accelerometry, and focused on children with obesity. Randomized controlled trial studies (RCTs) based on physical activity interventions focused on children with obesity (6 to 12 years old) from January 1991 to August 2018 were included. The post-intervention mean and standard deviation of the BMI Z-score and MVPA engaged time were extracted to calculate the results using random effects models. Of a total of 229 studies considered potentially eligible, only 10 RCTs met the inclusion criteria. There were improvements in the BMI Z-score for physical activity intervention groups, compared with non-intervention children in addition to a significant increase in time engaged in MVPA. In conclusion, interventions with a physical activity component in school-children with obesity seem to be effective at reducing BMI and producing an increase in time spent engaged in physical activity. Therefore, interventions based on physical activity should be considered one of the main strategies in treating childhood obesity.

Cluster Analysis of Physical Activity Patterns, and Relationship with Sedentary Behavior and Healthy Lifestyles in Prepubertal Children: Genobox Cohort.

Sedentary habits during childhood are associated with adverse health outcomes. The aim of this work was to cluster lifestyle behaviors and metabolic biomarkers to establish different patterns in children. Their physical and sedentary activities were evaluated by accelerometry, and questionnaires that included lifestyle behaviors, such as adherence to a Mediterranean diet, anthropometry and blood biochemical markers. Cluster analysis was performed to establish different groups based on physical activity levels. A total of 489 children were finally selected. Cluster 1 included children with a mostly sedentary state, whereas Cluster 3 included the most active children and Cluster 2 included children that did not fit into either the sedentary or the highly active groups. In Cluster 3, 56% of children were in a sports club, and a lower percentage used electronic devices in their rooms compared to the other groups. Cluster 1 children exhibited higher insulin, HOMA-IR and triacylglycerides with respect to the other groups. No differences were found regarding adherence to a Mediterranean diet. The choice to practice an extracurricular sport could be an influencing factor to increase exercise and ensure an active lifestyle in children. Reducing or limiting screen time mainly in children's rooms could contribute to an active lifestyle.

Acute Effects of Beetroot Juice Supplements on Resistance Training: A Randomized Double-Blind Crossover.

The ingestion of beetroot juice (BJ) has been associated with improvements in physical performance in endurance sports, however the literature on resistance training (RT) is scarce. The aim of this study was to investigate the acute effects of BJ compared to a placebo (PLA) on muscular endurance and movement concentric velocity during RT. Twelve healthy men performed an incremental RT test (back squat and bench press) with three sets, at 60%, 70%, and 80% of their repetition maximum (1-RM). Movement velocity variables, total number of repetitions performed until concentric failure, blood lactate, and ratings of perceived effort post-training were measured. A higher number of repetitions were recorded with BJ compared to those with PLA (13.8 ± 14.4; p < 0.01; effect size (ES) = 0.6). Differences were found at 60% 1-RM (9 ± 10; p < 0.05; ES = 0.61) and 70% 1-RM (3.1 ± 4.8; p < 0.05; ES = 0.49), however, no differences were found at 80% 1-RM (1.7 ± 1; p = 0.12; ES = 0.41). A greater number of repetitions was performed in back squat (13.4 ± 13; p < 0.01; ES = 0.77), but no differences were observed in bench press (0.4 ± 5.1; p = 0.785; ES = 0.03). No differences were found for the rest of the variables (p > 0.05). Acute supplementation of BJ improved muscular endurance performance in RT.

Changes in Physical Activity Patterns from Childhood to Adolescence: Genobox Longitudinal Study.

Longitudinal changes of physical activity (PA) from childhood into adolescence have not been accurately described yet for the Spanish population. The aim of this study is to evaluate the changes of PA, assessed by accelerometry and anthropometric measures in a cohort of 213 children from the prepubertal to pubertal period, focusing on those with valid data from both time points (n = 75). Sedentary time (ST) increased about 50%, while all PA intensities declined from the pre-pubertal to pubertal period. Light PA (LPA) was the major contributor, decreasing by about 30%. Boys were more active than girls in both periods, but they showed a higher decline in PA, especially moderate-to-vigorous PA (MVPA). The proportion who reached the recommendation of 60 min of MVPA decreased by 33.3% in boys and 4.6% in girls. Children with obesity or overweight had lower MVPA than those with normal-weight in the pre-pubertal period, but no differences were found in the pubertal period. This study shows a decrease of PA and an increase of sedentarism in the transition from childhood to adolescence, particularly in boys. Regardless of body weight, adolescents tend to be less active. Therefore, prevention programs should be implemented to achieve optimal PA and reduce sedentarism during infancy considering the differences found by sex.

Evaluation of the Predictive Ability, Environmental Regulation and Pharmacogenetics Utility of a BMI-Predisposing Genetic Risk Score during Childhood and Puberty.

Polygenetic risk scores (pGRSs) consisting of adult body mass index (BMI) genetic variants have been widely associated with obesity in children populations. The implication of such obesity pGRSs in the development of cardio-metabolic alterations during childhood as well as their utility for the clinical prediction of pubertal obesity outcomes has been barely investigated otherwise. In the present study, we evaluated the utility of an adult BMI predisposing pGRS for the prediction and pharmacological management of obesity in Spanish children, further investigating its implication in the appearance of cardio-metabolic alterations. For that purpose, we counted on genetics data from three well-characterized children populations (composed of 574, 96 and 124 individuals), following both cross-sectional and longitudinal designs, expanding childhood and puberty. As a result, we demonstrated that the pGRS is strongly associated with childhood BMI Z-Score (B = 1.56, SE = 0.27 and p-value = 1.90 × 10-8), and that could be used as a good predictor of obesity longitudinal trajectories during puberty. On the other hand, we showed that the pGRS is not associated with cardio-metabolic comorbidities in children and that certain environmental factors interact with the genetic predisposition to the disease. Finally, according to the results derived from a weight-reduction metformin intervention in children with obesity, we discarded the utility of the pGRS as a pharmacogenetics marker of metformin response.

Oxidative stress and inflamatory plasma biomarkers in respiratory syncytial virus bronchiolitis.

INTRODUCTION: Oxidative stress (OS) plays a crucial role in the pathogenesis of inflammatory lung diseases. OBJECTIVES: (i) We determined whether acute bronchiolitis (AB) caused by respiratory syncytial virus (RSV) induced OS; (ii) assessed whether OS biomarkers correlated with the severity of RSV-AB; and (iii) studied whether the levels of interleukins are associated with OS biomarkers. METHODS: We performed an observational study by comparing healthy infants (Group 1) with RSV-AB infants, classified as Group 2 (pulse oximetry (SpO2 ) >93%), and Group 3 (SpO2 ≤ 92%), which needed oxygen therapy. Blood samples were collected to determine the levels of lipid peroxidation (LPO) products (LPO), total glutathione (TG), oxidised glutathione (GSSG), reduced glutathione (GSH), glutathione peroxidase (GPx), interleukins (ILs) IL-10, IL-6, IL-8, interferon-gamma (IFNγ), tumour necrosis factor-alpha (TNFα) and macrophage inflammatory proteins (MIP α and MIP ß). RESULTS: Forty-six RSV-AB infants (47% needed oxygen therapy) and 27 healthy infants were included. The GSH/GSSG ratio was lower in RSV-AB infants than in Group 1 (P<0.001). GSSG and GPx were significantly higher in Group 3. GSSG predicted the need for oxygen therapy with an optimal cut-off point of 15 µM/g for haemoglobin. The GSH/GSSG ratio negatively correlated with IL-6 (P: 0.014), IL-8 (P: 0.014) and IL-10 (P: 0.033). Group 3 exhibited a direct correlation between GPx and IL-10 levels (P: 0.024) and between LPO and MIP ß (P: 0.003). CONCLUSIONS: RSV induced OS in AB. An increase in GSSG correlated with the disease severity in the infants. OS may contribute to the pathogenesis of RSV-AB.

Profile of oxidant and antioxidant activity in prepubertal children related to age, gender, exercise, and fitness.

Tissue damage resulting from oxidative stress induced by a pathological condition might have more serious consequences in children than in adults. Researchers have not yet identified particular markers - alone or in combination with others - of oxidative stress, or their role in pediatric diseases. The aim of this study was to identify gender-based biomarkers for measuring oxidative stress. Oxidative biomarkers were studied in 138 healthy Spanish children (85 boys, 53 girls) 7 to 12 years of age, at the prepubertal (Tanner I) stage, independent of body mass index (BMI), age, fitness (measured by 20-m shuttle run test), and physical activity (measured by participation in an after-school exercise program). The oxidative biomarkers measured were lipid peroxidation products, total nitrites, protein carbonyls, and oxidized glutathione (GSSG). The antioxidant biomarkers measured were total glutathione (TG), reduced glutathione (GSH), superoxide dismutase activity (SOD), and glutathione peroxidase activity. In the study population, height, weight, waist circumference, and BMI were lower in girls than in boys. For oxidative biomarkers, boys had higher levels of protein carbonyl than girls (p < 0.001). In spite of this, girls had higher levels of GSSG (p < 0.001) and TG (p = 0.001), and a lower GSH/GSSG ratio (p < 0.001) than boys. For the antioxidant response, girls had higher levels of SOD (p = 0.002) than boys. All analyses were adjusted for BMI, age, fitness, and physical activity. In conclusion, prepubertal girls had higher oxidative stress than boys, in addition to higher levels of SOD, independent of age, BMI, fitness, and physical activity.

Evaluation of metabolic risk in prepubertal girls versus boys in relation to fitness and physical activity.

BACKGROUND: Low levels of cardiorespiratory fitness (CRF) and physical activity (PA) are associated with a risk of the development of metabolic syndrome. Contradictory findings are reported in the literature regarding the influence of sex and CRF and PA on metabolic changes. OBJECTIVE: The aim of this study was to analyze the effects of CRF and PA on lipid and carbohydrate metabolism biomarkers in boys and girls. METHODS: A total of 82 prepubertal boys and 55 girls (7-12 years of age) were classified according to sex, low or high CRF, and performance or nonperformance of PA. Anthropometric and blood pressure (BP) measurements, plasma lipid profile values, glucose and insulin levels, and homeostasis model assessment for insulin resistance were analyzed. RESULTS: The percentage of boys with high CRF and performance of PA was higher than that of girls (P < 0.05). When children of the same sex were compared, higher values for body mass index and waist circumference z-scores were found for boys with low CRF compared with boys with high CRF (P < 0.001) without differences between girls, and in all groups classified by PA. Systolic and diastolic BPs were higher in boys than in girls, in both CRF and PA groups (P < 0.05). In the low CRF and no PA groups, girls had higher plasma glucose, total cholesterol, and low-density lipoprotein cholesterol levels than boys, with higher high-density lipoprotein cholesterol and apolipoprotein A levels (P < 0.05). CONCLUSIONS: Sex in relation to CRF and PA could affect the plasma lipid profile. These changes in girls are associated with low CRF and low levels of PA. Considering these results, we suggest the need to improve CRF and promote PA, especially in girls, to reduce metabolic risk.