Impact of a nationwide school policy on body mass index in Danish school children: An interrupted time series analysis.

Objectives: A new school policy mandating 45 min physical activity daily during school was introduced in Denmark in 2014. We aimed to evaluate the effect of this policy on BMI in school-aged children. It was hypothesized that the school policy would decrease BMI, especially in the obese fraction of the population (90th percentile BMI). Study design: This register-based study was conducted as a natural experiment. Methods: Analyses were based on data from The National Child Health Register that contains nationwide data on height and weight from mandatory preventive health examinations completed by school nurses or medical doctors during pre-preparatory classes (0th-3rd grade) and lower secondary education (7th-9th grade). A total of 401,517 children were included in the analyses with annual repeated cross-sectional data covering the period from 2012 to 2018. The effect of the school policy was evaluated using an interrupted time series approach comparing pre- and post-policy slopes in BMI, stratified by sex and age-group. Results: In boys, no significant differences were observed in mean BMI slopes from pre-to post-policy in either age-group. In girls, post-policy slopes were significantly higher compared to pre-policy in both age-groups (0th-3rd grade: ß:0·034 kg/m2, 95%-CI: (0·024; 0·043), p-value: <0·001; 7th-9th grade: ß:0·066 kg/m2, 95%-CI: (0·028; 0·103), p-value: 0·001). No significant differences in slopes were observed in BMI at the 90th percentile from pre-to post-policy for both sexes and across both age-groups. Adjustment for leisure-time physical activity as a potential time-varying confounder did not alter the findings. Conclusions: In conclusion, we did not detect a significant decrease in BMI levels among school-aged children following the introduction of a nationwide school policy specifying daily physical activity in school. If anything, a small positive change in BMI was observed in girls. More research is needed to understand whether structural changes similar to this requirement are able to prevent overweight and obesity in children and adolescents.

The metabolic syndrome is frequent in children and adolescents with type 1 diabetes compared to healthy controls.

OBJECTIVE: There is a rise in overweight and obesity among children and adolescents with type 1 diabetes (T1D) in parallel with the rise in the metabolic syndrome (MetS) among children and adolescents. The aim of the study was to describe the prevalence and characteristics of MetS in children and adolescents with T1D compared to their healthy counterparts. RESEARCH DESIGN AND METHODS: The study includes two Danish cohorts; (i) the Copenhagen cross sectional cohort 2016 of 277 children and adolescents with T1D that attend the pediatric outpatient clinic at a large hospital in greater Copenhagen and (ii) the CHAMPS-study DK which is a population-based cohort study of Danish children and adolescents (control cohort). Participants were categorized to have MetS if at least two of the following criteria were met: (i) systolic and/or diastolic blood pressure ≥ 90th percentile, (ii) waist circumference ≥90th percentile, and (iii) triglyceride ≥90th percentile and/or HDL ≤10th percentile. RESULTS: The prevalence of children with Mets in the T1D cohort was higher than in the control cohort (p = 0.002). Moreover, participants with T1D had MetS at a lower level of BMI (p < 0.001) and waist circumference (p < 0.001) than participants with MetS from the control cohort (z-scores = 0.90 and 1.51). Participants with MetS were younger than the other T1D participants (median 12.8 [9.9,14.8] vs. median 14.6 [11.2,16.9] years, p = 0.006). CONCLUSIONS: Children and adolescents with T1D have an increased risk of MetS compared to healthy controls and clinicians and caretakers should consider early prevention and health promotion strategies.

Reference serum percentile values of adiponectin, leptin, and adiponectin/leptin ratio in healthy Danish children and adolescents.

The adipokines adiponectin and leptin play key roles in human metabolic regulation and have gained great attention as biomarkers for various metabolic pathologies. Though, pediatric reference values are few and needed. This study aims to establish age- and sex-specific adipokine reference percentiles based on healthy Danish school children. Further, it elucidates sex-specific differences in associations between z-scores of examined adipokines and metabolic variables. Serum adiponectin and serum leptin from 853 observations of healthy Danish schoolchildren aged 8-17 years (median 10.0) were quantified by immunoassays. Age- and sex-specific adipokine reference percentiles were calculated cross-sectionally using the LMS method, and adipokine z-scores were calculated from the fitted model. Multiple linear regression models were used to examine sex-specific differences in associations between adipokine z-scores and various metabolic variables. Girls had a higher median value of adiponectin (11.31 vs. 10.65 µg/mL, p < .001) and leptin (2.30 vs. 1.00 ng/mL, p < .001) and a lower median value of adiponectin/leptin ratio (4.64 vs. 10.76, p < .001) compared to boys. Sex-specific differences were found in associations between adiponectin z-score and HDL (p = .010), between leptin z-score and waist circumference z-score (p = .027) and LDL (p = .048), and between adiponectin/leptin ratio z-scores and waist circumference z-score (p = .044) and LDL (p = .040). Reference percentiles of adiponectin, leptin, and adiponectin/leptin ratio are presented in this paper. To our knowledge, this study is the first to demonstrate sex-specific differences in associations between adipokine z-scores and waist circumference z-score and lipids, respectively in healthy children and adolescents.

Reference intervals in Danish children and adolescents for bone turnover markers carboxy-terminal cross-linked telopeptide of type I collagen (ß-CTX), pro-collagen type I N-terminal propeptide (PINP), osteocalcin (OC) and bone-specific alkaline phosphatase (bone ALP).

PURPOSE: Bone turnover markers (BTM) are gaining ground in clinical practice but to fully use their potential there is a need for establishing valid reference intervals (RI). Consequently, the purpose of the study was to establish general RI as well as suggested clinical RI for carboxy-terminal cross-linked telopeptide of type I collagen (ß-CTX), pro-collagen type I N-terminal propeptide (PINP), osteocalcin (OC) and bone-specific alkaline phosphatase (bone ALP) in children and adolescents. METHOD: BTM were measured on Danish children and adolescents participating in the CHAMPS-study DK. A total of 762 participants were included (8-18 years, 50.4% girls) contributing a total of 1410 study visits. The RI was calculated based on 2-years age spans. Participants with biochemical signs of metabolic bone disease were excluded. RESULTS: The differences in RI between age groups clearly reflect changes in growth with an initial increase in BTM, greatest in boys, and a subsequent decrease most pronounced in girls. ß-CTX and PINP are markers most affected by these changes, compared to OC and bone ALP. The suggested clinical 95% RI included participants with vitamin D insufficiency but no biochemical signs of metabolic bone disease which did not markedly alter the RI. CONCLUSION: RI for ß-CTX, PINP, OC and bone ALP varies with age and sex. ß-CTX and PINP which reflect bone resorption and formation processes are mostly affected by these changes. We suggest a set of clinically applicable 95% RI for the four BTM to heighten the usefulness and generalizability of the RI.

Bone mineral density at age 7 years does not associate with adherence to vitamin D supplementation guidelines in infancy or vitamin D status in pregnancy and childhood: an Odense Child Cohort study.

Vitamin D supplementation in infancy is recommended to prevent rickets. At the population level, its effects on bone mineralisation are largely unknown. We aimed to explore whether adherence to national vitamin D supplementation guidelines (10 µg/d up to the age of 2 years), supplementation at the ages of 5 and 7 years, and serum 25-hydroxyvitamin D (s-25(OH)D) at various time points associated with bone mineral density (BMD) at the age of 7 years in the Odense Child Cohort, Denmark (n 1194). High adherence was defined as supplementation with 10 µg of vitamin D 6-7 times per week during ≥80 % of the observation time. s-25(OH)D was analysed using LC-MS/MS. Total-body-less-head (TBLH) BMD was measured by dual-energy X-ray absorptiometry. At the median age of 18·1 months, 53·9 % (n 475/881) reported high adherence. The median s-25(OH)D was 64·7, 78·8, 46·0 and 71·8 nmol/l in early pregnancy, late pregnancy, cord blood and at 5 years, respectively. The mean TBLH BMD at the median age of 7·1 years was 0·613 (SD 0·049) g/cm2 (z-score +0·363 (SD 0·824)). In adjusted analyses, vitamin D supplementation up to 18 months, and at 5 and 7 years, was not associated with TBLH BMD. Similarly, no robust associations were found between TBLH BMD and s-25(OH)D at any time point. No associations were found for TBLH bone mineral concentration or bone area. In this population with relatively high s-25(OH)D concentrations, no consistent associations were found between adherence to vitamin D supplementation recommendations or vitamin D status in pregnancy or childhood, and bone mineralisation at the age of 7 years.

Bone mass development is sensitive to insulin resistance in adolescent boys.

PURPOSE: Insulin resistance may exert a negative influence on bone mass in childhood and adolescence. The objective was to assess the association between insulin resistance and total body less head (TBLH) bone mineral content (BMC) and to investigate whether body composition, physical activity or osteocalcin levels may influence this association. METHODS: A longitudinal study with follow-up over more than 6 years was performed and included 562 apparently healthy participants with a mean age of 9.6 years at baseline. Participants underwent DXA scanning at baseline. At the two follow-ups, participants had performed another DXA scanning, had blood samples taken for fasting insulin, glucose and osteocalcin and had physical activity measured with an accelerometer. HOMA-IR was calculated as an index of insulin resistance. RESULTS: HOMA-IR was negatively associated with TBLH BMC in boys at follow-ups (ß = -31.4, p < 0.001) after adjustment for maturity, height, bone area, and baseline level of TBLH BMC. The negative association remained almost unchanged after further adjustments for body composition and physical activity. No association between HOMA-IR and TBLH BMC was found in girls. CONCLUSION: Insulin resistance may be detrimental for bone development through puberty in boys independent of body composition and the level of physical activity.

Bone Mass Development in Childhood and Its Association with Physical Activity and Vitamin D Levels. The CHAMPS-Study DK.

This longitudinal study examined associations of bone mass with physical activity and vitamin D level over more than 6 years through puberty. A total of 663 participants (320 boys) with mean age 9.6 years at baseline (10-17 years at follow-up), underwent dual energy X-ray absorptiometry, anthropometry and blood samples for vitamin D at least twice during the study period (with three possible time-points). Physical activity was assessed using accelerometers at follow-up. A positive association was found between percent time spent at vigorous physical activity and total-body less head bone mineral content (ß = 5.8, p = 0.002). The magnitude of this association increased with maturational development; thus physical activity may have a greater influence on bone mass in the more mature participants. The vitamin D levels were also positively associated with bone mass. A high degree of tracking was observed with changes in anthropometric Z scores predictive of deviation from tracking. No environmental factor predicted deviation from tracking.

Insulin sensitivity is reduced in children with high body-fat regardless of BMI.

PURPOSE: To examine the association between insulin sensitivity and adiposity in children stratified according to their body mass index (BMI: normal weight, NW; overweight or obese, OW/OB) and body-fat percentage (BF%: adipose or NonAdipose), and determine whether cardiorespiratory fitness (CRF) ameliorates any deleterious associations. METHODS: This prospective cohort study comprises a cross-sectional and longitudinal analyses of data collected at baseline and 2 years later on children (7.7-13.4 years) attending public school in Denmark. Levels of CRF were measured using the Andersen test, whereas BF% was measured by dual-energy X-ray absorptiometry (DXA). Fasting plasma glucose and insulin concentrations were measured and the homoeostatic model assessment of insulin resistance (HOMA-IR) used to assess insulin sensitivity. RESULTS: Approximately 8% of children classified as normal weight by BMI had high BF% (NW + Adipose). Children with high BF% had significantly higher insulin (NW + adipose: 32.3%; OW/OB + Adipose: 52.2%) and HOMA-IR scores (NW + Adipose: 32.3%; OW/OB + Adipose: 55.3%) than children classified as NW without high BF% (reference group; NW + NonAdipose). Adjusting for CRF reduced this difference, but did not completely ameliorate these associations. Longitudinally, children with high BF% (OW/OB + Adipose or NW + Adipose) had significantly worse insulin sensitivity 2 years later than NW + NonAdipose children (All p < 0.001). The few children (n = 14) who improved their BMI or BF% during the 2 years follow-up, no longer had significantly worse insulin sensitivity than children with NW + NonAdipose. CONCLUSION: High BF% in children is associated with significantly lower insulin sensitivity even when BMI is considered NW. Longitudinally, insulin sensitivity is lower in children with high BF% with or without high BMI. The CRF was a significant covariate in these models, but CRF did not completely ameliorate the effects of high BF% on insulin sensitivity.

A Multi-Component Day-Camp Weight-Loss Program Is Effective in Reducing BMI in Children after One Year: A Randomized Controlled Trial.

The objective of the present study was to evaluate the effectiveness of a one-year multi-component immersive day-camp weight-loss intervention for children with overweight and obesity. The study design was a parallel-group randomized controlled trial. One hundred fifteen 11-13-year-old children with overweight and obesity were randomized into either: A six-week day-camp intervention arm focusing on increased physical activity, and healthy diet followed by a subsequent one-year family-based intervention, or a standard intervention arm consisting of one weekly exercise session for six weeks. Body mass index (BMI) was the primary outcome. BMI z-score, clustered cardiovascular risk z-score, and body composition were secondary outcomes. All outcomes were measured at baseline, six week-, and 52 week follow-up. After six weeks, children from the day-camp intervention arm had improved their BMI (-2.2 kg/m2 (95% CI -2.6 to -1.7, P<0.001)) and all secondary outcomes when compared to the children from the standard intervention arm. After 52 weeks, the day-camp intervention arm had a lower BMI (-1.2 kg/m2 (95% CI -1.8 to -0.5, P = 0.001)), and BMI z-score (-0.20 (95% CI -0.35 to -0.05, P = 0.008)), and clustered cardiovascular risk z-score (-0.23 (95% CI -0.37 to -0.08, P = 0.002)) compared to the standard intervention arm. No group differences were detected in body composition after 52 weeks. This study shows that the day-camp intervention arm is effective in reducing BMI and improving the metabolic health of children with overweight and obesity. However, the effects seem to be diminishing over time.

Exploring the Relationship between Adiposity and Fitness in Young Children.

PURPOSE: High levels of cardiorespiratory fitness (CRF) may attenuate the association between the excessive adiposity and the risks of cardiovascular and metabolic disease. The purpose of this study was to stratify children according to their body mass index (BMI) and adiposity (body fat percentage [BF%]) and to compare levels of CRF across subgroups. METHODS: This prospective cohort study comprises a cross-sectional and longitudinal analyses of data collected at baseline (n = 641) and 2 yr later (n = 579) on children (7.4-11.6 yr) attending public school in Denmark. Levels of CRF were measured using the Andersen test, whereas BF% was measured by dual-energy x-ray absorptiometry. RESULTS: There were 560 children (87.4%) classified as normal weight according to BMI at baseline, of which 46 (7.4%) were identified as having excessive BF%. These children had significantly lower CRF (mean [95% confidence interval]: -63.1 m [-100.2 to -25.9]) than children with normal BMI and normal BF%, and the effect of BF% on CRF was significantly worse in boys than girls. Overweight children with high BF% had significantly lower prospective (2 yr) CRF levels (-34.4 m [-58.0 to -10.7]) than children with normal BMI and BF%. However, children who improved their BMI and/or BF% classification during the 2-yr period achieved CRF levels (8.9 m [-30.2 to 47.9]), which were comparable with children with normal BMI and BF% at both measurement time points. CONCLUSION: The CRF levels in children are affected by BMI and BF%, although BF% appears to play a greater role. This association between BF% and CRF is sex dependent, with CRF levels in boys being affected to a greater extent by BF%. Children identified as "normal weight" by BMI but presenting with excessive BF% had significantly lower CRF than "normal weight" children with low BF%.

The influence of anthropometry and body composition on children's bone health: the childhood health, activity and motor performance school (the CHAMPS) study, Denmark.

Overweight, physical inactivity and sedentary behaviour have become increasing problems during the past decade. Increased sedentary behaviour may change the body composition (BC) by increasing the fat mass relative to the lean mass (LM). These changes may influence bone health to describe how anthropometry and BC predict the development of the bone accruement. The longitudinal study is a part of The CHAMPS study-DK. Children were DXA scanned at baseline and at 2-year follow-up. BC (LM, BF %) and BMC, BMD and BA were measured. The relationship between bone traits, anthropometry and BC was analysed by multilevel regression analyses. Of the invited children, 742/800 (93%) accepted to participate. Of these, 682/742 (92%) participated at follow-up. Mean (range) of age at baseline was 9.5 years (7.7-12.1). Height, BMI, LM and BF % predicted bone mineral accrual and bone size positively and independently. Height and BMI are both positive predictors of bone accruement. LM is a more precise predictor of bone traits than BF % in both genders. The effects of height and BMI and LM on bone accruement are nearly identical in the two genders, while changes in BF % have different but positive effects on bone accretion in both boys and girls.

Total body fat percentage and body mass index and the association with lower extremity injuries in children: a 2.5-year longitudinal study.

BACKGROUND: Overweight youths are generally recognised as being at increased risk of sustaining lower extremity injuries in sports. However, previous studies are inconclusive and choices for measuring overweight are manifold. OBJECTIVE: To examine two different measures of overweight, body mass index (BMI) and total body fat percentage (TBF%), as risk factors for lower limb injuries in a school-based cohort. STUDY DESIGN: A longitudinal cohort study. METHODS: A total of 632 school children, baseline age 7.7-12.0 years, were investigated. Whole body dual energy x-ray absorptiometry scans provided measures of TBF%. Measures of BMI were obtained by standard anthropometric methods. Musculoskeletal complaints were reported by parents answering weekly mobile phone text messages during 2.5 years. Injuries were diagnosed by clinicians. Leisure time sports participation was reported weekly using text messaging. RESULTS: During 2.5 years of follow-up, 673 lower extremity injuries were diagnosed. Children being overweight by both BMI and TBF% showed the highest risk of sustaining lower extremity injuries (IRR 1.38 (95% CI 1.05 to 1.81)). Children who were overweight using BMI and TBF% showed the highest risk of sustaining lower extremity injuries (IRR 1.38 (95% CI 1.05 to 1.81)). CONCLUSIONS: The risk of lower extremity injuries appeared to be increased for overweight children. When comparing two different measures of overweight, overweight by TBF% is a higher risk factor than overweight by BMI. This suggests that a high proportion of adiposity is more predictive of lower extremity injuries, possibly due to a lower proportion of lean muscle mass.

Six physical education lessons a week can reduce cardiovascular risk in school children aged 6-13 years: a longitudinal study.

AIMS: Cardiovascular disease (CVD) originates during childhood and adolescence. Schools are potentially effective settings for early public health prevention strategies. The aim of this study was to evaluate the effect of six physical education (PE) lessons on children's CVD risk. METHODS: This longitudinal study in 10 public schools (1218 children, aged 6-13 years), 6 intervention and 4 control schools evaluates a natural experiment, where intervention schools tripled PE to six lessons per week compared to the mandatory two PE lessons in the control schools. Baseline (2008) and 2-year follow-up measures were anthropometrics, cardiorespiratory fitness, blood pressure and blood samples providing lipids and measures for insulin resistance. Based on these variables, a composite risk score was calculated and used for further analysis. Multivariate multilevel mixed effect regression models were used to estimate effect of intervention taking the hierarchical structure of data into account. Individual, class and school were considered random effects. Intra class correlation (ICC) was calculated. RESULTS: Intervention significantly lowered mean of composite risk score with 0.17 SD (95% CI: -0.34 to -0.01). Six PE lessons per week had a beneficial effect on triglycerides (TG) levels (-0.18 SD, 95% CI: -0.36 to 0.00), systolic blood pressure (SBP) (-0.22 SD, 95% CI: -0.42 to -0.02) and insulin resistance (HOMA-IR) (-0.17 SD, 95% CI: -0.34 to 0.01). CONCLUSIONS: Six PE lessons at school can reduce children's CVD risk measured as a composite risk score. The changes in risk score are considered substantial in the perspective of public health strategy for preventing CVD in later life.

Effect of four additional physical education lessons on body composition in children aged 8-13 years--a prospective study during two school years.

BACKGROUND: Strategies for combating increasing childhood obesity is called for. School settings have been pointed out as potentially effective settings for prevention. The objective of this paper was to evaluate the effect of four additional Physical Education (PE) lessons/week in primary schools on body composition and weight status in children aged 8-13. METHODS: Children attending 2nd to 4th grade (n = 632) in 10 public schools, 6 intervention and 4 control schools, participated in this longitudinal study during 2 school years. OUTCOME MEASURES: Primary: Body Mass Index (BMI) and Total Body Fat percentage (TBF%) derived from Dual Energy X ray Absorptiometry (DXA). Secondary: the moderating effect of overweight/obesity (OW/OB) and adiposity based on TBF% cut offs for gender. RESULTS: Intervention effect on BMI and TBF% (BMI: ß -0.14, 95% CI: -0.33; 0.04, TBF%: ß -0.08, 95% CI:-0.65;0.49) was shown insignificant. However, we found significant beneficial intervention effect on prevalence of OW/OB based on BMI (OR 0.29, 95% CI: 0.11;0.72). The intervention effect on adiposity based on TBF% cut offs was borderline significant (OR 0.64, 95% CI:0. 39; 1.05). CONCLUSION: Four additional PE lessons/week at school can significantly improve the prevalence of OW/OB in primary schoolchildren. Mean BMI and TBF% improved in intervention schools, but the difference with controls was not significant. The intervention had a larger effect in children who were OW/OB or adipose at baseline.

The impact on children's bone health of a school-based physical education program and participation in leisure time sports: the Childhood Health, Activity and Motor Performance School (the CHAMPS) study, Denmark.

OBJECTIVE: To evaluate the effect of a school based physical education (PE) program and the amount of leisure time sport (LTS) on children's bone health and to examine if LTS influences the impact of school type on children's bone health. METHODS: Children attending "sports" schools (6 × 45 min PE lessons per week) were compared to children at "traditional" schools (2 × 45 min of PE lessons per week) in Svendborg, Denmark. Whole-body DXA scans were performed at baseline (2008) and at a two-year follow-up (2010). Bone mineral content (BMC), bone mineral density (BMD), and bone area (BA) were measured. Multilevel regression analyses examined the impact of school type and LTS participation on bone. RESULTS: 742/800 (93%) invited children accepted to participate. 682/742 (92%) participated at two-year follow-up. Mean (SD) age was 9.5 years (0.9) at baseline. A positive association between LTS and BMC, BMD (p<0.001) and for BA (p<0.05) (total body less head (TBLH) and lower limb (LL)) was found. All effects regarding school type were insignificant. CONCLUSION: A positive impact of attending LTS on bone traits was found. There was no effect on BMC, BMD and BA (TBLH, and LL) for children attending sports schools compared to traditional schools.

The intensity of physical activity influences bone mineral accrual in childhood: the childhood health, activity and motor performance school (the CHAMPS) study, Denmark.

BACKGROUND: Studies indicate genetic and lifestyle factors can contribute to optimal bone development. In particular, the intensity level of physical activity may have an impact on bone health. This study aims to assess the relationship between physical activity at different intensities and Bone Mineral Content (BMC), Bone Mineral Density (BMD) and Bone Area (BA) accretion. METHODS: This longitudinal study is a part of The CHAMPS study-DK. Whole-body DXA scans were performed at baseline and after two years follows up. BMC, BMD, and BA were measured. The total body less head (TBLH) values were used. Physical activity (PA) was recorded by accelerometers (ActiGraph, model GT3X). Percentages of different PA intensity levels were calculated and log odds of two intensity levels of activity relative to the third level were calculated. Multilevel regression analyses were used to assess the relationship between the categories of physical activity and bone traits. RESULTS: Of 800 invited children, 742 (93%) accepted to participate. Of these, 682/742 (92%) participated at follow up. Complete datasets were obtained in 602/742 (81%) children. Mean (range) of age was 11.5 years (9.7-13.9). PA at different intensity levels was for boys and girls respectively, sedentary 62% and 64%, low 29% for both genders and moderate to high 9% and 7% of the total time. Mean (range) BMC, BMD, and BA was 1179 g (563-2326), 0.84 g/cm2 (0.64-1.15) and 1393 cm2 (851-2164), respectively. Valid accelerometer data were obtained for a mean of 6.1 days, 13 hours per day. CONCLUSIONS: There 7was a positive relationship between the log odds of moderate to high-level PA versus low level activity and BMC, BMD and BA. Children with an increased proportion of time in moderate to high-level activity as opposed to sedentary and low-level activity achieved positive effects on BMC, BMD and BA.

Study protocol. The Childhood Health, Activity, and Motor Performance School Study Denmark (The CHAMPS-study DK).

BACKGROUND: An increasingly passive life-style in the Western World has led to a rise in life-style related disorders. This is a major concern for all segments of society. The county council of the municipality of Svendborg in Denmark, created six Sport Schools with increased levels of suitable physical activities, which made it possible to study the health outcomes in these children whilst comparing them to children who attended the 'normal' schools of the region using the design of a "natural experiment". METHODS: Children from the age of 6 till the age of 10, who accepted to be included in the monitoring process, were surveyed at baseline with questionnaires, physical examinations and physical and biological testing, including DXA scans. The physical examination and testing was repeated during the early stage of the study. Every week over the whole study period, the children will be followed with an automated mobile phone text message (SMS-Track) asking questions on their leisure time sports activities and the presence of any musculoskeletal problems. Children who report any such problems are monitored individually by health care personnel. Data are collected on demography, health habits and attitudes, physical characteristics, physical activity using accelerometers, motor performance, fitness, bone health, life-style disorders, injuries and musculoskeletal problems. Data collection will continue at least once a year until the children reach grade 9. DISCUSSION: This project is embedded in a local community, which set up the intervention (The Sport Schools) and thereafter invited researchers to provide documentation and evaluation. Sport schools are well matched with the 'normal' schools, making comparisons between these suitable. However, subgroups that would be specifically targeted in lifestyle intervention studies (such as the definitely obese) could be relatively small. Therefore, results specific to minority groups may be diluted. Nonetheless, the many rigorously collected data will make it possible to study, for example, the general effect that different levels of physical activity may have on various health conditions and on proxy measures of life-style conditions. Specifically, it will help answer the question on whether increased physical activity in school has a positive effect on health in children.

[Delayed psychomotor development caused by malignant infantile osteopetrosis]. / Psykomotorisk retardering på baggrund af malign infantil osteopetrose.

Malignant infantile osteopetrosis (MIOP) is a hereditary bone disorder caused by osteoclastic dysfunction. Within the first year of life affected children present with recurrent infections, vision impairment, failure to thrive, bone marrow failure, and at later stages neurological deficits and ultimately death. Bone marrow transplant (BMT) is the only curative treatment. We present a patient with MIOP, who showed the first symptoms at three weeks of age, and the disease was diagnosed at 11 months of age. The boy had a successful BMT after which the delayed psychomotor development improved.