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.

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.

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.

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.

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.

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.

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).

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.

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.

Anthropometric measures as fitness indicators in primary school children: The Health Oriented Pedagogical Project (HOPP).

AIMS: As children's fitness continues to decline, frequent and systematic monitoring of fitness is important. Easy-to-use and low-cost methods with acceptable accuracy are essential in screening situations. This study aimed to investigate how the measurements of body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR) relate to selected measurements of fitness in children. METHODS: A total of 1731 children from grades 1 to 6 were selected who had a complete set of height, body mass, running performance, handgrip strength and muscle mass measurements. A composite fitness score was established from the sum of sex- and age-specific z-scores for the variables running performance, handgrip strength and muscle mass. This fitness z-score was compared to z-scores and quartiles of BMI, WC and WHtR using analysis of variance, linear regression and receiver operator characteristic analysis. RESULTS: The regression analysis showed that z-scores for BMI, WC and WHtR all were linearly related to the composite fitness score, with WHtR having the highest R2 at 0.80. The correct classification of fit and unfit was relatively high for all three measurements. WHtR had the best prediction of fitness of the three with an area under the curve of 0.92 ( p < 0.001). CONCLUSIONS: BMI, WC and WHtR were all found to be feasible measurements, but WHtR had a higher precision in its classification into fit and unfit in this population.

The effects of a school-based physical activity intervention programme on children's executive control: The Health Oriented Pedagogical Project (HOPP).

AIMS: To assess the effects of a large school-based physical activity intervention on children's ability to resist distractions and maintain focus, known as executive control. METHODS: A quasi-experimental design with seven intervention and two control primary schools. The Health Oriented Pedagogical Project (HOPP) intervention consisted of 45 min of physical activity a day during school time for 6-8 months in addition to the regular weekly physical education lessons. A total of 1173 children, spanning from second grade (age 7 years) to sixth grade (age 12 years) were included in the analysis. Main outcome measures were executive control was measured at baseline and 1 year after using a modified Eriksen flanker task for the younger children (second and third grades) and a computerised Stroop task for the older children (fourth, fifth, and sixth grades). RESULTS: Both the intervention and control group showed improvements in executive control after 1 year. However, the children in the intervention group did not improve their performance more than those in the control group. CONCLUSIONS: No positive effect of the physical activity intervention programme on children's task performance was found, suggesting that the intervention did not affect children's executive control.

Waist circumference in 6-12-year-old children: The Health Oriented Pedagogical Project (HOPP).

AIMS: With overweight and obesity increasing worldwide, it has become ever more important to monitor the development and distribution of adiposity in children. This study investigated how the measurements of waist circumference (WC) and waist-to-height ratio (WHtR) in children 6-12 years old relate to earlier studies. METHODS: In 2015, 2271 children (boys, n = 1150) were measured for height, weight, and WC. Parental education level was used as a measure of socioeconomic status. RESULTS: A significant increase in WC with age was revealed for both sexes ( p < .0001). Boys at 10 and 12 years had a larger WC than girls; otherwise no difference between sexes was found. The WHtR decreased with age for girls ( p < .0001); 14% of the sample displayed a WHtR ≥ 0.50. Comparison with earlier studies showed a higher WC and WHtR despite no change in weight and body mass index. CONCLUSION: WC and WHtR are recommended as tools for identifying central obesity in children. The results indicate increased WC in 6-12-year-old children compared with earlier findings.

Objectively assessed moderate-to-vigorous physical activity levels among primary school children in Norway: The Health Oriented Pedagogical Project (HOPP).

AIMS: The objective was to investigate moderate-to-vigorous physical activity levels (MVPA) of primary school children at baseline of the Health Oriented Pedagogical Project (HOPP), Norway. METHODS: Data on 2123 children aged 6-12 years were included for analysis (75% participation rate). Average minutes per day in MVPA was objectively measured using accelerometry based on seven-day averages. The sample was analysed for age-, sex-, socioeconomic-, and season-related patterns. A linear regression investigated the moderating effect of these factors as well as body mass index and waist circumference. RESULTS: Some 86.5% of the sample had at least 60 min/day MVPA, averaging 90.7 min/day. The main differences in daily averages were between age groups 6½-9 and 10-12 ( p < .05). Boys (95.8 min/day, 95% CI: 94.1-97.5) were more active than girls (85.6 min/day, 95% CI: 83.9-87.2) in all age groups ( p < .0001). MVPA was lower by 3.5 min ( p < .0001) per additional year of age in the linear regression (R2 = 0.176) and was reduced by 20 min less per day in MVPA in the winter months compared with the summer months ( p < .0001). CONCLUSIONS: Physical activity levels are already in decline from 6-7 years old and are likely to continue to decline into adolescence. Interventions must therefore focus on primary school children.

Peer relationships and quality of life in 11-12-year-old children: The Health Oriented Pedagogical Project (HOPP).

AIMS: Social interactions play an important role in our everyday life. Studies on children's quality of life (QoL) show that peer relations are associated with both positive and negative outcomes. Popularity defines the degree to which a child is liked by his or her peers, whereas reciprocal friendship occurs when two children mutually nominate each other as friends. The overall aim was to examine associations between peer relations and children's QoL. METHODS: Baseline data were from the Health Oriented Pedagogical Project (HOPP). From a sample of 2297, 691 children aged 11-12 years participated. QoL was measured using the Norwegian version of the Inventory of Life Quality in Children and Adolescents (ILC). Popularity and friendship variables were based on number of nominations and represent quantitative features of peer relationships. RESULTS: Both popularity and reciprocal friendship had a positive association with children's QoL. Number of nominations (both for popularity and reciprocal friendship) played a significant role for the above-mentioned associations. Consequently, popularity (ß = 0.18) and reciprocal friendship (ß = 0.25) were associated with children's QoL with 95% CIs of 0.12-0.27 and 0.17-0.31, respectively. CONCLUSIONS: Findings from the current study contribute to contemporary research focused on children's QoL. Being able to rank reciprocal friendships, as well as recognizing that having more than one reciprocal friendship increases QoL, is important and could be beneficial for developing programs that promote high QoL, hence preventing possible maladjustments in a long-term perspective.

Reference intervals for serum lipids and prevalence of dyslipidaemia in 6-12-year-old children: The Health Oriented Pedagogical Project (HOPP).

AIMS: Elevated serum lipid concentrations in childhood are thought to be risk factors for the development of cardiovascular disease later in life. The present study aims to provide age- and gender-related reference intervals for total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, and non-HDL cholesterol in healthy school children. We also investigated the prevalence of dyslipidaemia using the published criteria for these biomarkers. METHODS: Venous blood and anthropometric data were collected from 1340 children in the HOPP study, aged between 6 and 12 years. Age- and gender-related reference intervals (2.5th and 97.5th percentiles) were established according to the IFCC recommendations, using the software RefVal 4.10. RESULTS: Gender differences were observed for total cholesterol and non-HDL cholesterol, but not for HDL cholesterol. Age differences were observed for total cholesterol. The reference intervals were in the range of 3.1-5.9 mmol/L for total cholesterol, 1.0-2.4 mmol/L for HDL cholesterol and 1.4-4.2 mmol/L for non-HDL cholesterol. Dyslipidaemia prevalence was as follows: increased TC 9.6%, decreased HDL 1.6%, and increased non-HDL 5.6%. CONCLUSIONS: Age- and gender-related reference intervals in a Norwegian population are similar to those reported in other countries. The prevalence of dyslipidaemia among Norwegian children is significant, emphasising the importance of appropriate reference intervals in clinical practice.

Handgrip strength in 6-12-year-old children: The Health Oriented Pedagogical Project (HOPP).

AIMS: The aim of the study was to describe the natural course of handgrip strength development in primary school children and to establish a reference material to be used in future screening studies. In addition, the study aims to investigate a possible association between handgrip strength and cardiovascular risk factors. METHODS: Anthropometric measures along with results for handgrip strength, endurance tests, blood pressure and cholesterol were measured on 2272 children of both sexes. An ROC analysis was used to estimate the suitability of handgrip strength as a predictor for known cardiometabolic risk factors. RESULTS: A reference material for handgrip strength is presented for boys and girls aged 6-12 years. The results indicate that handgrip strength is unsuitable as a predictor for cardiometabolic risk factors in children. CONCLUSIONS: The results may be used as reference values for handgrip strength in 6-12-year-old children of both sexes. Handgrip strength may not be used as a screening tool for cardiometabolic risk factors in pre-pubertal children.