Health Oriented Pedagogical Project Research Articles

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.

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.

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

BackgroundOverweight 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.MethodsThe 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.ResultsBetween 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.ConclusionCombination 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.

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.

Daily and Weekly Variation in Children's Physical Activity in Norway: A Cross-Sectional Study of The Health Oriented Pedagogical Project (HOPP).

Background The purpose of the study was to examine differences in objectively measured moderate-to-vigorous physical activity (MVPA min/day) and sedentary time (SED min/day) between different time domains as school hours, leisure time, and weekends. An additional objective addressed causal association between body mass and MVPA. Methods. The study sample consisted of 2015 subjects (51% girls) aged 6–12 years (9.46 ± 1.76) from the Health Oriented Pedagogical Project (HOPP) in south-east Norway. Six days of MVPA min/day and SED min/day were measured using accelerometers and presented as daily averages. The differences in physical activity (PA) were investigated between the time domains of school-hours, leisure time and weekends by age and sex. Data were analyzed using one-and two-way ANOVA. Results. The relative contribution of the different time domains in overall PA was found. Daily average of MVPA min/day and SED min/day differed significantly across the three time domains. The average weekend SED was 56 ± 3.45 and 82 ± 4.12 min/day less when compared with school hours and leisure time, respectively. On average children spent 27 ± 2.74 min/day less in MVPA during school hours, compared with leisure time (p < 0.001), and spent by 38 ± 2.10 min/day more during weekends compared to school hours (p < 0.001). Boys were more physically active than girls, and less time was spent in MVPA with age. Conclusion. With the objective of increasing PA in a child population, the findings indicate that PA intervention programs should target children with higher body mass, girls more than boys, older children more than younger, and during school hours and leisure time more than on weekends.

Presenting Health Status in Children Using a Radar Plot.

Background: To try out the feasibility of presenting the health status of children 6 to 12 years old by using radar plots. Methods: With data from the Health Oriented Pedagogical Project (HOPP) we have described the health status for 1340 children aged 6 to 12 years. We collected or calculated: stature, body mass, waist circumference, waist to height ratio, high density lipoprotein (HDL) and total cholesterol concentration, blood pressure, accelerometer assessed physical activity, endurance interval running performance, and quality of life. Pertinent variables were presented through a radar plot for both individual cases and groups. Results: The boys showed better endurance and recorded more moderate to vigorous physical activity than the girls. The activity level dropped from age 6 to age 12 for both sexes. The girls showed a lower systolic blood pressure compared with boys. Self-rated quality of life was high among boys and girls. Conclusions: This cohort showed good health and the radar plot made it easy to visualise health status for groups and individuals.

The Weather Impact on Physical Activity of 6-12 Year Old Children: A Clustered Study of the Health Oriented Pedagogical Project (HOPP).

It is commonly known that children do not engage in a sufficient amount of physical activity. Weather conditions and day length may influence physical activity of children. Little is known about the relationship between physical activity and seasons. The purpose of this study was to investigate the relationships between weather conditions and physical activity in 6–12 year old children based on hip-worn Actigraph wGT3X–BT accelerometer data. The study sample consisted of 2015 subjects aged 6–12 years from the Health Oriented Pedagogical Project (HOPP) study carried out in Horten municipality and Akershus county, Norway. Six days of sedentary and moderate-to-vigorous physical activity data was gathered in January–June and September–October, 2015, presented as daily averages. The accelerometer-monitored physical activity of children grouped within nine schools was matched with regional weather conditions and assessed with the means of linear mixed models. Increased day length was associated with decreased sedentary behavior. Warmer temperature and dry weather were associated with increased moderate-to-vigorous physical activity after adjusting for age and sex. One-hour increase in daylight resulted in a decrease of sedentary time by, on average, 2 min (95% CI = (−2.577, −0.798)). For every 5 °C increase in temperature (range: −0.95 and 15.51 °C) and dry weather, average moderate-to vigorous physical activity increased by 72 and 67 min (males and females, respectively) (p < 0.001). Days with precipitation had, on average, 10 fewer minutes of moderate-to-vigorous physical activity compared with days without precipitation (95% CI = (−16.704, −3.259)). Higher temperatures and dry weather led to higher physical activity levels, seeing larger increases among boys than girls. A school-based physical activity intervention program should be adjusted regarding local weather conditions in line with the present findings.

Changes in Quality of Life in Elementary School Children-The Health Oriented Pedagogical Project (HOPP).

Background: Quality of life (QoL) studies may provide information of change in health status in the population. Few studies have followed up previous cross-sectional studies to investigate any change in the QoL status of healthy children. The aim of the current study is to compare QoL in children 6–12 years old in two large cross-sectional studies of healthy children completed a decade apart. Methods: In the current study children and parents from nine elementary schools (n = 2816) were included in a cross-sectional study investigating children’s QoL. Using the Life Quality in Children and Adolescents (ILC), completed by both children and parents, the global QoL-score was estimated for 2297 children and 1639 parental reports. These results were compared to a similar study performed in 2004. The scores from both studies were divided into categories of below average, average and above average QoL. The percentage change of QoL between the two studies is presented. Results: Our results show that parents report that more children have below and above average QoL in 2015 compared to 2004. In contrast, more children scored in the average and above average QoL category in 2015 than in 2004. Conclusion: Parents reported lower QoL and children higher QoL in 2015 compared to 2004.

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

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. 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. 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 (β = 0.18) and reciprocal friendship (β = 0.25) were associated with children's QoL with 95% CIs of 0.12-0.27 and 0.17-0.31, respectively. 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.

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

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. 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. 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). 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.

Quality of life in primary school children: The Health Oriented Pedagogical Project (HOPP).

The primary aim of the present study was to evaluate the association between parents' level of education, measurements of physical attributes, and quality of life in a general sample of primary school children. The children's and the parents' versions of the Inventory of Life Quality in Children and Adolescents (ILC) were used to measure health-related quality of life (QOL) in 2140 school children (response rate 93%) and 1639 parents (response rate 71%) recruited from nine primary schools in Norway. A set of physical characteristics were also measured in the children: body mass index (BMI), waist circumference, average daily minutes of physical activity, aerobic fitness, and handgrip strength. The regression analysis showed stronger relationships between the covariates and QOL for the parents' assessments than for the children's. Parents' level of education was significantly related to children's QOL, with the strongest association for parental QOL assessment. Among the physical variables, aerobic fitness ( B = 0.01, p > .001 in both samples), and handgrip strength in the parents' sample ( B = 0.21, p < .05) were significantly related to the children's QOL. The present study replicated the well-known finding that parents' sociodemographic status is important for children's QOL. Our new contribution is to show that the physiological variables aerobic fitness and muscular strength also contributed significantly to explain variance in QOL. This opens up interesting perspectives on how to improve QOL among children through more emphasis on physical activity and physical fitness in schools.

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

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. 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. 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%. 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.

Development of weight and height in Norwegian children: The Health Oriented Pedagogical Project (HOPP).

High prevalence of overweight and obesity increases the disease burden with higher risk for an expanding set of chronic diseases, including cardiovascular disease, diabetes mellitus, chronic kidney disease, certain types of cancers and an array of musculoskeletal disorders. Over the last decades, trends in children's weight have changed worldwide. Anthropometric measurements of height and weight and calculations of body mass index (BMI) were recorded for 2297 children, aged 6-12 years. Percentiles for weight and height are presented, as well as overweight and obesity cut-off points according to International Obesity Task Force guidelines for each age group. Children's BMI is higher compared to older studies; however, a levelling-off of weight is evident, as 14-15% of the children are overweight in the present study. Children within the 90th and 97.5th percentiles display a higher annual increase in weight/height ratio compared to other percentiles. Parental level of education shows association with children's BMI. A levelling-off of weight gain among children is evident; however, overweight children tend to gain more weight than normal-weight children.

Cardiovascular risk factors in a child population: The Health Oriented Pedagogical Project (HOPP).

The main aim of the present study was to investigate the clustering of risk factors for cardiovascular diseases and metabolic syndrome in a large, healthy representative Norwegian child population. From a population of 2817, parents of 2297 children agreed to participate. Values of waist circumference (WC), total cholesterol (TC), high-density lipoprotein (HDL), systolic blood pressure (sysBP), haemoglobin-A1c (HbA1c) and Andersen aerobic fitness test were used to test clustering of cardiometabolic risk factors in this sample. Expected distributions of probability for zero to five risk factors are, respectively, 23.7%, 39.6%, 26.4%, 8.8%, 1.5% and 0.1%. A cardiometabolic risk score from zero to five for each individual was derived by adding the number of variables in the least desirable quartile (highest for WC, sysBP, TC and HbA1c; lowest for aerobic fitness and HDL). A risk ratio of 5.8 (95% confidence interval 0.7-46.9) was found for five risk factors, though the small sample size rendered the results non-significant. An explorative analysis combining children with four and five risk factors did not reveal any significant clustering either. No clustering of risk factors was found among Norwegian children aged 6-12 years.

Factors affecting running performance in 6-12-year-olds: The Health Oriented Pedagogical Project (HOPP).

The purpose of this study was to examine factors affecting running performance in children. A cross-sectional study exploring the relationships between height, weight, waist circumference, muscle mass, body fat percentage, relevant biomarkers, and the Andersen intermittent running test in 2272 children aged 6 to 12 years. Parental education level was used as a non-physiological explanatory variable. Mean values (SD) and percentiles are presented as reference values. Height (β = 6.4, p < .0001), high values of haemoglobin (β = 18, p = .013) and low percentage of body fat (β = -7.5, p < .0001) showed an association with results from the running test. In addition, high parental education level showed a positive association with the running test. Boys display better running performance than girls at all age ages, except 7 years old, probably because of additional muscle mass and less fatty tissue. Height and increased level of haemoglobin positively affected running performance. Lower body fat percentage and high parental education level correlated with better running performance.

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

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. 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. 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). 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.

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

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. 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. 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. 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.

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

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. 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. 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. 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.

The health Oriented pedagogical project (HOPP) - a controlled longitudinal school-based physical activity intervention program

BackgroundThe prevalence of non-communicable diseases (NCDs) is increasing worldwide, also among children. Information about primary prevention of NCD’s is increasing; however, convincing strategies among children is needed. The present paper describes the design and methods in the Health Oriented Pedagogical Project (HOPP) study. The main objective is to evaluate the effects of a school-based physical activity intervention program on cardio-metabolic risk factors. Secondary objectives include assessment of physical, psychological and academic performance variables.MethodsThe HOPP study is a 7 years longitudinal large-scale controlled intervention in seven elementary schools (n = 1545) with two control schools (n = 752); all aged 6–11 years at baseline. The school-based physical activity intervention program includes an increase in physical activity (PA) of 225 min/week as an integrated part of theoretical learning, in addition to the curriculum based 90 min/week of ordinary PA. Primary outcomes include cardio-metabolic risk factors measured as PA level, BMI status, waist circumference, muscle mass, percent fat, endurance test performance, total serum cholesterol, high-density lipoprotein (HDL), non-HDL, micro C-reactive protein (mCRP) and long-term blood sugar (HbA1c). In addition, secondary outcomes include anthropometric growth measures, physical fitness, quality of life (QoL), mental health, executive functions, diet and academic performance.DiscussionHOPP will provide evidence of effects on cardio-metabolic risk factors after a long-term PA intervention program in elementary schoolchildren. School-based PA intervention programs may be an effective arena for health promotion and disease prevention.Trial registrationThe study is registered in Clinical trials (ClinicalTrials.gov Identifier: NCT02495714) as of June 20th – 2015, retrospectively registered. The collection of baseline values was initiated in mid-January 2015.