Relations between the levels of moderate to vigorous physical activity, BMI, dietary habits, cognitive functions and attention problems in 8 to 9 years old pupils: network analysis (PACH Study).

BACKGROUND: Physical activity (PA) and dietary habits (DH) play a crucial role on quality of life and health outcomes from various aspects. METHODS: This study aims to investigate the relations between recommended daily levels of moderate to vigorous physical activity (MVPA) in 8 to 9 year old pupils, and their body mass index (BMI), DH, cognitive functions and attention problem scores by network analysis. Study participants were split into two groups based on their MVPA levels on weekdays. RESULTS: Our findings suggest that children who reach recommended MVPA levels consume more vegetables and fruits, eat breakfast more frequently, have better motor speed and lower impulsivity score. CONCLUSIONS: The number of interlinkages between various parameters in network structure for children who do not reach recommended MVPA levels is greater and more intense, highlighting the differences between the groups and suggesting that different interventions and approaches to improve/change lifestyle habits might be used.

Retinal venular vessel diameters are smaller during ten days of bed rest.

Older individuals experience cardiovascular dysfunction during extended bedridden hospital or care home stays. Bed rest is also used as a model to simulate accelerated vascular deconditioning occurring during spaceflight. This study investigates changes in retinal microcirculation during a ten-day bed rest protocol. Ten healthy young males (22.9 ± 4.7 years; body mass index: 23.6 ± 2.5 kg·m-2) participated in a strictly controlled repeated-measures bed rest study lasting ten days. High-resolution images were obtained using a hand-held fundus camera at baseline, daily during the 10 days of bed rest, and 1 day after re-ambulation. Retinal vessel analysis was performed using a semi-automated software system to obtain metrics for retinal arteriolar and venular diameters, central retinal artery equivalent and central retinal vein equivalent, respectively. Data analysis employed a mixed linear model. At the end of the bed rest period, a significant decrease in retinal venular diameter was observed, indicated by a significantly lower central retinal vein equivalent (from 226.1 µm, CI 8.90, to 211.4 µm, CI 8.28, p = .026), while no significant changes in central retinal artery equivalent were noted. Prolonged bed rest confinement resulted in a significant (up to 6.5%) reduction in retinal venular diameter. These findings suggest that the changes in retinal venular diameter during bedrest may be attributed to plasma volume losses and reflect overall (cardio)-vascular deconditioning.

A pilot study: Exploring the influence of COVID-19 on cardiovascular physiology and retinal microcirculation.

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects the cardiovascular system. The current study investigated changes in heart rate (HR), blood pressure (BP), pulse wave velocity (PWV), and microcirculation in patients recovering from Coronavirus disease 2019 (COVID-19) infection. METHODOLOGY: Out of 43 initially contacted COVID-19 patients, 35 (30 males, 5 females; age: 60 ± 10 years; and body mass index (BMI): 31.8 ± 4.9) participated in this study. Participants were seen on two occasions after hospital discharge; the baseline measurements were collected, either on the day of hospital discharge if a negative PCR test was obtained, or on the 10th day after hospitalization if the PCR test was positive. The second measurements were done 60 days after hospitalization. The vascular measurements were performed using the VICORDER® device and a retinal blood vessel image analysis. RESULTS: A significant increase in systolic BP (SBP) (from 142 mmHg, SD: 15, to 150 mmHg, SD: 19, p = 0.041), reduction in HR (from 76 bpm, SD: 15, to 69 bpm, SD: 11, p = 0.001), and narrower central retinal vein equivalent (CRVE) (from 240.94 µm, SD: 16.05, to 198.05 µm, SD: 17.36, p = 0.013) were found. Furthermore, the trends of increasing PWV (from 11 m/s, SD: 3, to 12 m/s, SD: 3, p = 0.095) and decreasing CRAE (from 138.87 µm, SD: 12.19, to 136.77 µm, SD: 13.19, p = 0.068) were recorded. CONCLUSION: The present study investigated cardiovascular changes following COVID-19 infection at two-time points after hospital discharge (baseline measurements and 60 days post-hospitalization). Significant changes were found in systolic blood pressure, heart rate, and microvasculature indicating that vascular adaptations may be ongoing even weeks after hospitalization from COVID-19 infection. Future studies could involve conducting additional interim assessments during the active infection and post-infection periods.

Vascular Responses following Light Therapy: A Pilot Study with Healthy Volunteers.

(1) Background: Studies have reported the effectiveness of light therapy in various medical conditions. Our pilot study aimed to assess the effect of Maharishi light therapy (MLT) on physiological parameters, such as the heart rate (HR), HR variability (HRV), blood pressure (BP), BP variability (BPV), and the retinal microvasculature of healthy participants; (2) Methodology: Thirty (14 males and 16 females) healthy, non-smoking participants between 23 and 71 years old (46 ± 18 years) were included in this randomized crossover study. Each participant was tested with a placebo (using LED light) and gem lights, 24 h apart. Hemodynamic parameters were recorded during the session, and 24 h heart rate and BP levels were assessed via mobile devices. Retinal vascular responses were captured with fundus images and the subsequent analysis of retinal vessel widths. A linear model, using repeated measures ANOVA, was used to compare the responses across the sexes and to assess the effect of the MLT; (3) Results: Changes in the central retinal artery equivalent (CRAE) (p < 0.001) and central retinal vein equivalent (CRVE) (p = 0.002) parameters were observed. CRAE and CRVE decreased under MLT and increased under the placebo condition from before to after. However, the baseline values of the participants already differed significantly before the application of any therapy, and the variation in the retinal vessel diameters was already large in the baseline measurements. This suggests that the observed effect results may only reflect naturally occurring fluctuations in the microcirculation and not the effect of MLT. Furthermore, no significant effects were observed in any other investigated parameters; (4) Conclusion: Our study with healthy participants finds significant changes in retinal parameters, but the biological variation in the baseline measurements was large to begin with. This suggests that the observed effect results only reflect naturally occurring fluctuations in the microcirculation and not the effect of MLT. However, in the future, larger studies in which MLT is applied for longer periods and/or in patients with different diseases could discover the physiological impacts of this type of therapy.

A school-based physical activity intervention on psychosocial health outcomes among 11- and 12-year-olds - HOPP-project.

The purpose was to investigate the effect of a school-based physical activity (PA)-intervention among 11- and 12-year-olds (6th- and 7th graders) across 4 years. Seven primary schools in Horten municipality in Norway received 45 min daily extra PA as part of the curriculum. The intervention started in 2015 with follow-up in 2016-2019. The effect was measured after 1-4 years of participation, among the same children (6th to 7th grade) and among new children starting in 6th grade. Two control schools received no additional PA beyond the regular PA at school. The Self-reported Strength and Difficulties Questionnaire (SDQ-S) focusing on internalizing and externalizing difficulties were administrated. A statistical model for repeated measurements was used and adjusted for parents' educational level, sex, age, and waist-to-height ratio (WHtR). The significance level was p ≤ 0.01. In total, 1221 children completed the SDQ-S. SDQ-S scores were stable, and difficulties were relatively low. The control group had significantly lower SDQ-S scores than the intervention group at start, indicating fewer difficulties. The adjusted effect within the intervention schools showed a borderline significant increase in total difficulty scores between 2018 and 2019 (mean difference: 1.02, 95% CI: -1.82, -0.23, p ≤ 0.01). Educational level showed a weak negative correlation with total difficulty score (r = -0.1). No significant change was reported within the control schools. Few psychosocial health problems among 11- and 12-year-olds were detected. The borderline increase in total difficulty score that was seen for the intervention schools, is believed to be of limited clinical relevance.

Increase in peak oxygen uptake and Andersen test performance in children from age six to ten: The Health Oriented Pedagogical Project (HOPP).

The increased prevalence of non-communicable disease risk factors among children because of lack of physical activity is concerning. The Health Oriented Pedagogical Project was set up to combine learning activities and physical activity, thus reducing sedentariness during school time. The current study aimed to measure and describe the longitudinal and cross-sectional development of oxygen uptake and running performance in children at ages six and ten. The validity of the Andersen Test in predicting V̇O2peak in these age groups was also evaluated. Eighty-six children (53 boys, 33 girls) with complete datasets at ages 6 and 10 years were included in the longitudinal study, while 192 children (106 boys, 86 girls) were included in the cross-sectional analysis because they missed data from 1 year. Oxygen uptake was measured using a metabolic analyser and maximal treadmill running, while the distance covered during the AT determined running performance. Body mass, height, and waist-to-height ratios were recorded. Multiple regression analysis was used to assess the association between oxygen uptake and running performance. The cross-sectional results did not differ from the longitudinal data for anthropometrical data, oxygen uptake and running performance. Height, body mass and waist-to-height ratio did not differ between the sexes at ages six or ten. Boys had significantly higher peak oxygen uptake than girls at 6 years of age, irrespective of how oxygen uptake was expressed. Allometric scaling of oxygen uptake revealed differences between sexes at both ages. Longitudinal running performance increased in both sexes from 6 to 10 years. Boys ran significantly longer only at age ten. The association between oxygen uptake and running performance varied according to how the oxygen uptake was expressed and with sex and age. Ten-year-old girls had the highest correlations in the longitudinal investigation, from r 2 = 0.48 (fV̇O2peak) to 0.65 (rV̇O2peak) between AT and V̇O2peak. The AT was found to be as valid as the 20-m shuttle run test in estimating peak oxygen uptake, with a random measurement error of approximately 11% of mean values.

Hematology reference intervals in 6-12-year-old children: the health-oriented pedagogical project (HOPP).

Reference intervals are essential for correct interpretation of laboratory test results, supporting clinicians in distinguishing between healthy and sick individuals. The present study aims to establish pediatric reference intervals for hematological parameters based on a large population of healthy schoolchildren. Blood samples were obtained from 1351 children 6-12 years of age participating in the Health-Oriented Pedagogical Project (HOPP). Reference intervals for hematological parameters were estimated by the nonparametric method following the CLSI C28-A3 guidelines. Reference intervals were estimated as 2.5th and 97.5th percentiles with corresponding 90% confidence intervals. While hematocrit and MCV required age and sex partitioning, hemoglobin and erythrocytes were partitioned for age. The remaining parameters, MCH, MCHC, platelets and white blood cell counts did not require partitioning. While red blood cell parameters exhibited an increasing trend with age, there was a slight decrease in leukocytes, lymphocytes, basophils and platelets with age. The remaining parameters were stable across our age span.

Health and Academic Performance With Happy Children: A Controlled Longitudinal Study Based on the HOPP Project.

Background: Overweight/obesity in children and adolescents, largely arising due to increased food intake and reduced physical activity, is a major health concern. Physical activity (PA) integrated into learning has been shown to not only lead to improved health outcomes and wellbeing but also positively affect academic performance. The Health and Academic Performance with Happy Children (HAPHC) project aims at enhancing health and academic performance in elementary school children via implementation of a daily unit of Physical Activity Across the Curriculum (PAAC), which is carried out within the school setting. In this project, PA as an integrated part of learning will be evaluated and the learning material adapted for a large scale implementation across several European countries. Methods: In three European countries (Austria, Slovenia, and Belgium), 12 primary schools in total will be recruited to act as either intervention or control school in a large intervention study, which applies the PAAC pedagogy during lectures. It is estimated that, at least 3,000+ children across the three countries will be recruited in this study. All teachers of intervention schools will receive training and materials/teaching equipment that will allow them to integrate a daily PA unit of 45 min over 3 years across the curriculum. In response to the daily PA intervention, the following primary outcomes will be assessed: changes in health related physiological factors, academic achievement, psycho-social aspects and wellbeing. Impact of Project: The HAPHC project aims at promoting public health by increasing PA at an early age within the school setting and therewith preventing the increasing risk of non-communicable diseases across Europe. HAPHC project aims to develop knowledge and materials, which will ensure that the PAAC can be scalable to other European countries. Trial Registration Number: ClinicalTrials.gov, identifier: NCT04956003.

Variation in Child Serum Cholesterol and Prevalence of Familiar Hypercholesterolemia: The Health Oriented Pedagogical Project (HOPP).

Early stages of atherosclerosis may develop in childhood due to hyperlipidemia. The aims are to investigate the prevalence of familiar hypercholesterolemia in 6 to 12-year-old children and to study the deviation in cholesterol measures. Anthropometric data and venous blood were collected from children participating in the Health Oriented Pedagogical Project (HOPP). Out of 18 children with TC > 6.0 mmol/L, 15 were tested genetically and none diagnosed with FH. The prevalence of TC > 6.0 mmol/L declined from 1.3% in 2015 to 0.5% in 2016. The mean TC was 4.30 mmol/L both years, which is lower than in earlier studies. Usage of a single TC measurement and a threshold of TC > 6.0 mmol/L in screening children for FH, may not be a good screening strategy. While lipid values have a good reliability across 2 measurements, there are variations in individual TC levels across 1 year.

Children's hair cortisol and hair testosterone concentrations in response to environmental changes: from summer holidays to school.

Elevated hair cortisol concentrations in children have been linked to several stress-related conditions, including school-related demands. However, little is known about changes in hair testosterone in children. The present study investigated changes in hair cortisol and hair testosterone concentrations in the time course of four months - from summer holidays until mid of autumn of the following school year - in 60, 10-12-year-old (11.31 ± 0.63) school children (29 girls). Children's mental health was assessed by the strengths and difficulties questionnaire (SDQ) and related to hair cortisol and hair testosterone levels. Body mass index, waist-to-height ratio, and parental education were evaluated as potential confounders. In girls, the expected increase of hair cortisol concentrations was observed during school as compared to summer holidays, partly accounted for by peer- and emotional problems and the increase of HTC. In boys, hair cortisol and testosterone concentrations were significantly higher. Hair cortisol increased only slightly, while hair testosterone decreased significantly during school. The findings suggest a reciprocal influence of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axis, differentially affecting girls' and boys' hormone production in response to environmental changes.

COVID-19 and its effects on endothelium in HIV-positive patients in sub-Saharan Africa: Cardiometabolic risk, thrombosis and vascular function (ENDOCOVID STUDY).

BACKGROUND: COVID-19 has affected almost every country in the world, especially in terms of health system capacity and economic burden. People from sub-Saharan Africa (SSA) often face interaction between human immunodeficiency virus (HIV) infection and non-communicable diseases such as cardiovascular disease. Role of HIV infection and anti-retroviral treatment (ART) in altered cardiovascular risk is questionable and there is still need to further carry out research in this field. However, thus far it is unclear, what impact the COVID-19 co-infection in people living with HIV (PLHIV), with or without therapy will have. The ENDOCOVID project aims to investigate whether and how HIV-infection in COVID-19 patients modulates the time course of the disease, alters cardiovascular risk, and changes vascular endothelial function and coagulation parameters/ thrombosis risk. METHODS: A total of 1026 patients will be included into this study. Cardiovascular research PLHIV with (n = 114 in each of the three recruiting centers) - or without - ART (n = 114 in each of the three recruiting centers) with COVID-19 and HIV-negative with COVID-19 (n = 114 in each of the three recruiting centers) will be carried out via clinical and biochemical measurements for cardiovascular risk factors and biomarkers of cardiovascular disease (CVD). Vascular and endothelial function will be measured by brachial artery flow-mediated dilatation (FMD), carotid intima-media thickness (IMT) assessments, and retinal blood vessel analyses, along with vascular endothelial biomarkers and cogualation markers. The correlation between HIV-infection in COVID-19 PLHIV with or without ART and its role in enhancement of cardiovascular risk and endothelial dysfunction will be assessed at admission, weekly, at discharge and, 4 weeks post-discharge (if possible). IMPACT OF PROJECT: The ENDOCOVID project aims to evaluate in the long-term the cardiovascular risk and vascular endothelial function in PLHIV thus revealing an important transitional cardiovascular phenotype in COVID-19. The study was registered under clinicaltrials.gov (NCT04709302).

Subcutaneous Adipose Tissue Measured by B-Mode Ultrasound to Assess and Monitor Obesity and Cardio-Metabolic Risk in Children and Adolescents.

Monitoring of children at heightened risk of cardio-metabolic diseases raises the need for accurate assessment of obesity. A standardized approach for measuring subcutaneous adipose tissue (SAT) by bright-mode ultrasound was evaluated in relation to body indices and anthropometry in a cross-sectional sample of 76 South African children (7-10 years) and 86 adolescents (13-17 years) to assess cardio-metabolic risk. SAT was higher in girls as compared to boys (children: 50.0 ± 21.7 mm > 34.42 ± 15.8 mm, adolescents: 140.9 ± 59.4 mm > 79.5 ± 75.6 mm, p < 0.001) and up to four times higher in adolescents than in children. In children, measures of relative body weight showed only a poor correlation to SAT (BMI: r = 0.607, p < 0.001), while in adolescents, BMI correlated high with SAT (r = 0.906, p < 0.001) based on high rates of overweight and obesity (41.8%). Children with identical BMIs may have large differences (>2-3-fold) in their amount of SAT. The moderate association to systolic (r = 0.534, r = 0.550, p < 0.001) and diastolic blood pressure (r = 0.402, r = 0.262, p < 0.001) further substantiates that SAT measured by ultrasound provides an accurate, safe and easy applicable approach for monitoring in children and adolescents at cardio-metabolic risk.

The effect of physical activity intervention and nutritional habits on anthropometric measures in elementary school children: the health oriented pedagogical project (HOPP).

BACKGROUND: Overweight and obesity are a burden of the modern world that requires urgent action. Prevention has proven to be efficient in the fight against overweight and obesity. As many children gain excessive weight at an early age, intervention during school years are important. While daily physical activity (PA) is known to have an influence on overweight and obesity prevention, the importance of a healthy lifestyle, including dietary habits, should not be underestimated. The aim of this study was to assess how a combination of daily PA and healthy/unhealthy diet affect the anthropometric measures of 4th graders in Norway. METHODS: The Health Oriented Pedagogical Project (HOPP) is a longitudinal intervention in primary school children, which includes increased amount of daily physical activity during teaching- active learning. Assessed were weight, muscle and bone mass, as well as fat mass, using a bio-impedance Tanita scale. A dietary survey, Ungkost 2000, with 18 multiple-choice questions was used to evaluate the overall nutrition characteristics of the children. RESULTS: Between 2015 and 2018, a total of 917 (intervention group n = 614, control group n = 303) 4th graders from nine different schools from the south-east part of Norway participated. We observed that daily PA and a regular healthy diet increases-while an unhealthy diet decreases-muscle and bone mass despite daily PA. Daily PA appears to counteract some of the effects of an unhealthy diet on weight and fat mass. In addition, daily PA and a regular intake of fruits and berries lowers weight and fat mass in children with overweight. CONCLUSION: Combination of daily 45-minute of PA and a healthy diet leads to reductions in body weight and incease in muscle and bone mass in elementary school children.

Relative Performance of Machine Learning and Linear Regression in Predicting Quality of Life and Academic Performance of School Children in Norway: Data Analysis of a Quasi-Experimental Study.

BACKGROUND: Machine learning techniques are increasingly being applied in health research. It is not clear how useful these approaches are for modeling continuous outcomes. Child quality of life is associated with parental socioeconomic status and physical activity and may be associated with aerobic fitness and strength. It is unclear whether diet or academic performance is associated with quality of life. OBJECTIVE: The purpose of this study was to compare the predictive performance of machine learning techniques with that of linear regression in examining the extent to which continuous outcomes (physical activity, aerobic fitness, muscular strength, diet, and parental education) are predictive of academic performance and quality of life and whether academic performance and quality of life are associated. METHODS: We modeled data from children attending 9 schools in a quasi-experimental study. We split data randomly into training and validation sets. Curvilinear, nonlinear, and heteroscedastic variables were simulated to examine the performance of machine learning techniques compared to that of linear models, with and without imputation. RESULTS: We included data for 1711 children. Regression models explained 24% of academic performance variance in the real complete-case validation set, and up to 15% in quality of life. While machine learning techniques explained high proportions of variance in training sets, in validation, machine learning techniques explained approximately 0% of academic performance and 3% to 8% of quality of life. With imputation, machine learning techniques improved to 15% for academic performance. Machine learning outperformed regression for simulated nonlinear and heteroscedastic variables. The best predictors of academic performance in adjusted models were the child's mother having a master-level education (P<.001; ß=1.98, 95% CI 0.25 to 3.71), increased television and computer use (P=.03; ß=1.19, 95% CI 0.25 to 3.71), and dichotomized self-reported exercise (P=.001; ß=2.47, 95% CI 1.08 to 3.87). For quality of life, self-reported exercise (P<.001; ß=1.09, 95% CI 0.53 to 1.66) and increased television and computer use (P=.002; ß=-0.95, 95% CI -1.55 to -0.36) were the best predictors. Adjusted academic performance was associated with quality of life (P=.02; ß=0.12, 95% CI 0.02 to 0.22). CONCLUSIONS: Linear regression was less prone to overfitting and outperformed commonly used machine learning techniques. Imputation improved the performance of machine learning, but not sufficiently to outperform regression. Machine learning techniques outperformed linear regression for modeling nonlinear and heteroscedastic relationships and may be of use in such cases. Regression with splines performed almost as well in nonlinear modeling. Lifestyle variables, including physical exercise, television and computer use, and parental education are predictive of academic performance or quality of life. Academic performance is associated with quality of life after adjusting for lifestyle variables and may offer another promising intervention target to improve quality of life in children.

Cardiometabolic risk factors and early indicators of vascular dysfunction: a cross-sectional cohort study in South African adolescents.

OBJECTIVES: Prevalence of child and adolescents' overweight and obesity in low- and middle-income countries has increased dramatically. Simultaneously, the incidence of pre-hypertension/hypertension is also increasing in children, which, in turn, predisposes these children to the risk of cardiovascular disease (CVD) in later life. The present study assessed cardiometabolic risk factors and early indicators of vascular dysfunction in adolescents from a low socio-economic rural area in South Africa. DESIGN: Cross-sectional cohort study. SETTING: The study was conducted in public schools in Mthatha, OR Tambo district municipality, Eastern Cape Province, South Africa. PARTICIPANTS: A total of 244 adolescents (188 females) of African ancestry aged 13-16 years were enrolled. PRIMARY AND SECONDARY OUTCOME MEASURES: Anthropometric and haemodynamic measures and pulse wave velocity (PWV) were related to overweight/obesity and hypertension. Blood markers of cardiometabolic syndrome were assessed as well as vascular function (via PWV). RESULTS: One-third (33.0%) of the adolescents exceeded the age and sex-specific body mass index percentiles for overweight (≥85th) or obesity (>95th) with a prevalence of 61.1% pre-hypertensives in this group. Overweight/obesity and hypertension were associated with higher triglycerides (lean:overweight: 0.79<1.01 mmol/L; normotensive:hypertensive: 0.82<0.89 mmol/L). Fasting glucose was higher in hypertensive as compared to normotensive adolescents (4.85>4.69 mmol/L, p<0.05). PWV was elevated in 25.9% of the children and significantly correlated with asymmetric dimethylarginine and systolic blood pressure (p<0.001). CONCLUSION: Overweight/obesity and hypertension show a high prevalence in rural South African youth. Almost half of the studied adolescents are at risk for developing CVD. The high association between cardiometabolic risk factors and PWV further suggests that hypertension in adolescents may promote the progression of CVD in adulthood. Early detection of those at risk and the implementation of preventive strategies in underprivileged young people is urgently needed to stop the progression of vascular damage and manifestation of CVD in rural African children.

Distribution of creatinine and estimated glomerular filtration rate in healthy schoolchildren: The Health Oriented Pedagogical Project (HOPP).

Glomerular filtration rate (GFR) measured by urinary clearance of inulin is considered the gold standard for assessment of kidney function in both adults and children. Because the procedure is cumbersome, GFR is estimated (eGFR) using algorithms based on the observed relationship between measured GFR (mGFR) and more accessible biomarkers such as creatinine and cystatin C. In children, most of the data on this relationship is retrieved from patients with reduced kidney function. Nonetheless, eGFR equations are widely in use in healthy children to evaluate kidney status and diagnose kidney disease. The aim of the present study was to compare the distribution of eGFR using two established pediatric eGFR equations incorporating age, height and serum creatinine (Schwartz-Lyon and Full Age Spectrum-height) and two recently published equations restricted to age and serum creatinine (Lund-Malmö Revised 18 and European Kidney Function Consortium equation) in 1200 healthy schoolchildren age 6-12 years. In addition, we present 2.5th, median and 97.5th percentiles for serum creatinine stratified by age and gender. Depending on the equation used, mean eGFR ranged from 101.6 to 115.4 mL/min/1.73 m2. The lower 2.5th percentile ranged from 83.3 to 89.0 mL/min/1.73 m2 and the fraction of children with eGFR < 90 mL/min/1.73 m2 ranged from 2.9% to 9.8%. In conclusion, expected values of eGFR in healthy children are significantly dependent on the equation used. When decision limits for diagnosis or classification are applied to eGFR results, the related equation should be clearly stated.

Population-based reference intervals for ferritin, iron, transferrin and transferrin saturation and prevalence of iron deficiency in 6-12-year-old children: the Health Oriented Pedagogical Project (HOPP).

Appropriate reference intervals are important for correct interpretation of laboratory test results. The primary objective of the present study was to establish pediatric reference intervals for biochemical markers essential in the assessment of iron status. As a secondary objective we calculated the prevalence of iron deficiency according to WHO recommendations. Blood samples were obtained from 1355 healthy children 6-12 years of age participating in the Health Oriented Pedagogical Project (HOPP). For our primary objective, data from 1333 children were used to establish reference intervals for ferritin, iron, transferrin and transferrin saturation. Following the CLSI C28-A3 guidelines, the 2.5th and 97.5th percentiles with corresponding 90% confidence intervals, were estimated by the nonparametric method. None of the measured analytes required partitioning for age or sex. The prevalence of iron deficiency was 8.2%, which is higher than reported in other populations.

Cardiovascular effects of air pollution: current evidence from animal and human studies.

Air pollution is a global health concern. Particulate matter (PM)2.5, a component of ambient air pollution, has been identified by the World Health Organization as one of the pollutants that poses the greatest threat to public health. Cardiovascular health effects have been extensively documented, and these effects are still being researched to provide an overview of recent literature regarding air pollution-associated cardiovascular morbidity and mortality in humans. Additionally, potential mechanisms through which air pollutants affect the cardiovascular system are discussed based on human and additional animal studies. We used the strategy of a narrative review to summarize the scientific literature of studies that were published in the past 7 yr. Searches were carried out on PubMed and Web of Science using predefined search queries. We obtained an initial set of 800 publications that were filtered to 78 publications that were relevant to include in this review. Analysis of the literature showed significant associations between air pollution, especially PM2.5, and the risk of elevated blood pressure (BP), acute coronary syndrome, myocardial infarction (MI), cardiac arrhythmia, and heart failure (HF). Prominent mechanisms that underlie the adverse effects of air pollution include oxidative stress, systemic inflammation, endothelial dysfunction, autonomic imbalance, and thrombogenicity. The current review underscores the relevance of air pollution as a global health concern that affects cardiovascular health. More rigorous standards are needed to reduce the cardiovascular disease burden imposed by air pollution. Continued research on the health impact of air pollution is needed to provide further insight.

The prevalence of pediatric metabolic syndrome-a critical look on the discrepancies between definitions and its clinical importance.

INTRODUCTION: The Metabolic Syndrome (MetS) describes the clustering of cardio-metabolic risk factors-including abdominal obesity, insulin resistance, elevated blood pressure, high levels of triglycerides, and low levels of high-density lipoproteins-that increase the risk for developing cardiovascular diseases and type 2 diabetes mellitus. However, a generally accepted definition of MetS in pediatric patients is still lacking. OBJECTIVES: The aim was to summarize current prevalence data of childhood MetS as well as to discuss the continuing disagreement between different pediatric definitions and the clinical importance of such diagnosis. METHODOLOGY: A systematic literature search on the prevalence of pediatric MetS was conducted. Articles that were published during the past 5 years (2014-2019), using at least one of four predetermined classifications (International Diabetes Federation, Cook et al., Ford et al., and de Ferranti et al.), were included. RESULTS: The search resulted in 1167 articles, of which 31 publications met all inclusion criteria. DISCUSSION: The prevalence of MetS ranged between 0.3 and 26.4%, whereby the rising number of children and adolescents with MetS partly depended on the definition used. The IDF definition generally provided the lowest prevalences (0.3-9.5%), whereas the classification of de Ferranti et al. yielded the highest (4.0-26.4%). In order to develop a more valid definition, further research on long-term consequences of childhood risk factors such as abdominal obesity, insulin resistance, hypertension, and dyslipidemia is needed. There is also a temptation to suggest one valid, globally accepted definition of metabolic syndrome for pediatric populations but we believe that it is more appropriate to suggest definitions of MetS that are specific to males vs. females, as well as being specific to race/ethnicity or geographic region. Finally, while this notion of definitions of MetS specific to certain subgroups is important, it still needs to be tested in future research.