Motor performance is not related to injury risk in growing elite-level male youth football players. A causal inference approach to injury risk assessment.

OBJECTIVE: To identify the causal relation between growth velocity and injury in elite-level youth football players, and to assess the mediating effects of motor performance in this causal pathway. DESIGN: Prospective cohort study. METHODS: We measured the body height of 378 male elite-level football players of the U13 to U15 age categories three to four months before and at the start of the competitive season. At the start of the season, players also performed a motor performance test battery, including motor coordination (Körperkoordinationstest für Kinder), muscular performance (standing broad jump, counter movement jump), flexibility (sit and reach), and endurance measures (YoYo intermittent recovery test). Injuries were continuously registered by the academies' medical staff during the first two months of the season. Based on the causal directed acyclic graph (DAG) that identified our assumptions about causal relations between growth velocity (standardized to cm/y), injuries, and motor performance, the causal effect of growth velocity on injury was obtained by conditioning on maturity offset. We determined the natural indirect effects of growth velocity on injury mediated through motor performance. RESULTS: In total, 105 players sustained an injury. Odds ratios (OR) showed a 15% increase in injury risk per centimetre/year of growth velocity (1.15, 95%CI: 1.05-1.26). There was no causal effect of growth on injury through the motor performance mediated pathways (all ORs were close to 1.0 with narrow 95%CIs). CONCLUSIONS: Growth velocity is causally related to injury risk in elite-level youth football players, but motor performance does not mediate this relation.

Early assessment of weight velocity can support frontline health workers in predicting malnutrition in HIV-exposed infants: preliminary results from a DREAM cohort in Malawi.

BACKGROUND: Children born to HIV-positive mothers are particularly susceptible to malnutrition. Currently, monitoring programs rely on punctual anthropometric measurements to assess child growth. Growth velocities could be an additional tool in identifying critical time windows for prevention and implementation of early intervention for malnutrition. METHODS: A retrospective analysis was conducted using data from 817 HIV exposed but uninfected children extracted from DREAM program database. By using the WHO reference for growth standards, patterns of weight velocity for different intervals of assessment from one to 18 months of age were explored. Odds ratios and multinomial logistic regressions between selected weight velocity Z-scores thresholds and successive malnutrition indices (at 6, 12, 18 months of age) were calculated. RESULTS: Weight velocity was above the standard mean in the first 3 months, then progressively declined over time. In children with normal nutritional status, significant risks of becoming malnourished (mild malnutrition - underweight [OR 10.8; 95% CI: 4.5-26], chronic malnutrition - stunting [OR 8.3; 95% CI: 2-34.9] and acute malnutrition - wasting [OR 11.7; 95% CI: 1.5-90.5]) started when weight velocity Z-scores <0, at all interval ages. Multinomial regression showed that in the first 6 months, the weight velocity decrements strongly impacted on underweight (OR 17.9; 95% CI: 4-80.7), while the risk of Stunting occurred later at 18 months (OR 8.7; 95% CI: 4.3-17.6), with highest impact at the lowest thresholds. CONCLUSIONS: The assessment of weight velocity Z-scores, coupled with the already validated malnutrition indices, can support frontline health workers in early prediction of child malnutrition and performing nutritional counselling in the context of HIV/AIDS and food insecurity.

Adolescent pregnancy and linear growth of infants: a birth cohort study in rural Ethiopia.

BACKGROUND: Evidences indicate that the risk of linear growth faltering is higher among children born from young mothers. Although such findings have been documented in various studies, they mainly originate from cross-sectional data and demographic and health surveys which are not designed to capture the growth trajectories of the same group of children. This study aimed to assess the association between young maternal age and linear growth of infants using data from a birth cohort study in Ethiopia. METHODS: A total of 1423 mother-infant pairs, from a birth cohort study in rural Ethiopia were included in this study. They were followed for five time points, with three months interval until the infants were 12 months old. However, the analysis was based on 1378 subjects with at least one additional follow-up measurement to the baseline. A team of data collectors including nurses collected questionnaire based data and anthropometric measurements from the dyads. We fitted linear mixed-effects model with random intercept and random slope to determine associations of young maternal age and linear growth of infants over the follow-up period after adjusting for potential confounders. RESULTS: Overall, 27.2% of the mothers were adolescents (15-19 years) and the mean ± SD age of the mothers was 20 ± 2 years. Infant Length for Age Z score (LAZ) at birth was negatively associated with maternal age of 15-19 years (ß = - 0.24, P = 0.032). However, young maternal age had no significant association with linear growth of the infants over the follow-up time (P = 0.105). Linear growth of infants was associated positively with improved maternal education and iron-folate intake during pregnancy and negatively with infant illness (P < 0.05). CONCLUSION: Young maternal age had a significant negative association with LAZ score of infants at birth while its association over time was not influential on their linear growth. The fact that wide spread socio economic and environmental inequalities exist among mothers of all ages may have contributed to the non-significant association between young maternal age and linear growth faltering of infants. This leaves an opportunity to develop comprehensive interventions targeting for the infants to attain optimal catch-up growth.

[Nutrition, growth and inequality in the long term: What does anthropometric history teach about Spain?] / Nutrición y desigualdad en el largo plazo: ¿qué enseña la historia antropométrica sobre España?

This article underlines the relevance of anthropometric history among the disciplines concerned with health and nutrition. The examination of changes on the nutritional status and inequality in Spain focused the 4th Anthropometric History Workshop held at the beginning of 2018 where 18 original contributions were presented and discussed. We first show the ability of human stature to approach the impact of socioeconomic processes and environmental changes on the nutritional status over the last centuries. Then it is proceeded to present the main contents and advances achieved in the workshop. The papers coped with diverse dimensions of inequality regarding nutritional health and its determinants since the end of the 18th century until 2015. Aside of height and weight at different ages, principally adult ones, others anthropometric indicators were analyzed such as sexual dimorphism and low weight at birth. The results illustrate the large prevalence of malnutrition and social inequality in past Spain. These problems persisted over a good part of the 20th century (i.e. stunting) and, they acquired a different nature since the 1980s as the increasing prevalence of overweight and obesity reveals. It is concluded that the determinants of nutritional status and health-related inequalities request multidimensional approaches and the dialogue between social sciences and biomedical sciences. Knowing about their dimensions in the past and their evolution over time provides a valuable basis in order to understand current problems in these areas and to address future public policies more adequately on childhood and adolescence.

Este artículo destaca la importancia de la historia antropométrica entre las ciencias preocupadas por la nutrición y la salud. La evolución del estado nutricional y de la desigualdad en España medida por indicadores antropométricos es el principal objetivo de un conjunto de 18 contribuciones presentadas y discutidas en el IV Workshop de Historia Antropométrica celebrado a comienzos de 2018.Después de mostrar la capacidad de la estatura humana como representación del impacto de los procesos socioeconómicos y de los cambios ambientales en el estado nutricional durante los últimos siglos, se presentan las principales aportaciones y avances realizados en el taller. Las contribuciones abordan distintas facetas de la desigualdad de la salud nutricional y de sus determinantes desde finales del siglo XVIII hasta 2015. Además de la talla y del peso a diferentes edades (principalmente adultas), se incluyen otros indicadores antropométricos, como el dimorfismo sexual y el bajo peso al nacimiento. Los resultados reflejan graves problemas de malnutrición y de desigualdad en el pasado que persisten con otra naturaleza en la actualidad: retraso en el crecimiento hasta la década de los sesenta y creciente prevalencia de obesidad desde 1980.Se concluye que los determinantes del estado nutricional y de la desigualdad de la salud requieren un enfoque multidimensional y de diálogo entre las ciencias sociales y las biomédicas. Conocer su dimensión en el pasado y su evolución proporciona un valioso aporte de conocimiento para entender con mayor perspectiva los problemas actuales y poder intervenir con atino en las políticas futuras.

Assessment of sella turcica area and skeletal maturation patterns of children with unilateral cleft lip and palate.

OBJECTIVES: The aim of this case-control study was to assess sella turcica area and skeletal maturity in children with unilateral cleft lip and palate (UCLP) and compare with those of non-cleft children. SETTING AND SAMPLE POPULATION: A total of 85 UCLP patients aged 7.5-17.08 years (Group 1: age 7-11 years, Group 2: age 11-14 years and Group 3: age 14-18 years) were compared with 85 control subjects without clefts who were divided into similar age groups. MATERIALS AND METHODS: Hand-wrist radiographs and cervical vertebra maturation stages (CVMS) were used to evaluate growth. Lateral cephalograms were traced, and reference points of sella were determined. Sella turcica area was measured using a digital planimeter. RESULTS: Comparison of overall growth on hand-wrist radiographs revealed no significant difference between cleft and non-cleft subjects. However, according to the chronological age groups, Group 1-UCLP showed statistically significant delay in skeletal maturation when compared with the age-matched control subjects (P = .05). This difference was due to the delay among male subjects (P = .05). As for CVMS, more significant maturation delay was observed in Group 1-UCLP (P = .001) and was attributable to both male and female subjects (P = .05). Comparison of sella turcica area showed no significant difference between UCLP patients and controls. CONCLUSION: Although children with CLP showed significant delay in growth when they are younger compared with the non-cleft children, sella turcica area measurements were similar for individuals in both groups.

Energy intake functions and energy budgets of ectotherms and endotherms derived from their ontogenetic growth in body mass and timing of sexual maturation.

Ectothermic and endothermic vertebrates differ not only in their source of body temperature (environment vs. metabolism), but also in growth patterns, in timing of sexual maturation within life, and energy intake functions. Here, we present a mathematical model applicable to ectothermic and endothermic vertebrates. It is designed to test whether differences in the timing of sexual maturation within an animal's life (age at which sexual maturity is reached vs. longevity) together with its ontogenetic gain in body mass (growth curve) can predict the energy intake throughout the animal's life (food intake curve) and can explain differences in energy partitioning (between growth, reproduction, heat production and maintenance, with the latter subsuming any other additional task requiring energy) between ectothermic and endothermic vertebrates. With our model we calculated from the growth curves and ages at which species reached sexual maturity energy intake functions and energy partitioning for five ectothermic and seven endothermic vertebrate species. We show that our model produces energy intake patterns and distributions as observed in ectothermic and endothermic species. Our results comply consistently with some empirical studies that in endothermic species, like birds and mammals, energy is used for heat production instead of growth, and with a hypothesis on the evolution of endothermy in amniotes published by us before. Our model offers an explanation on known differences in absolute energy intake between ectothermic fish and reptiles and endothermic birds and mammals. From a mathematical perspective, the model comes in two equivalent formulations, a differential and an integral one. It is derived from a discrete level approach, and it is shown to be well-posed and to attain a unique solution for (almost) every parameter set. Numerically, the integral formulation of the model is considered as an inverse problem with unknown parameters that are estimated using a series of empirical data.

Racial differences in crossing major growth percentiles in infancy.

BACKGROUND/AIMS: We examined associations of ever crossing upwards ≥2 (vs <2) major weight-for-length (WFL) percentiles in the first 24 months with obesity at 5 years among white and black children. METHODS: We included 10 979 white and 1245 black children from the Linked CENTURY Study with percentile crossing data in all four 6-month periods in the first 24 months and obesity (age-specific and sex-specific body mass index ≥95th percentile) at 5 years. We used adjusted logistic regression models and stratified by race. RESULTS: 64% of children crossed upwards ≥2 major WFL percentiles in the first 2 years. Among white children, 12% were obese vs 7% for <2 crossings, while among black children the frequencies were 23% vs 9%. Black children (adjusted OR 2.94, 2.04 to 4.23) who had ever crossed upwards ≥2 major WFL percentiles had a higher odds of obesity at age 5 than white children (adjusted OR 1.89, 1.64 to 2.18) (interaction p=0.02). CONCLUSIONS: Our results suggest that rapid weight gain in infancy is more deleterious among black than white children for later obesity.

Monte Carlo simulation of body height in a spatial network.

BACKGROUND/OBJECTIVES: Recent evidence suggests clustering of human body height. We want to assess the consequences of connectedness in a spatial network on height clustering in an artificial society. SUBJECTS/METHODS: We used an agent-based computer modelling technique (Monte Carlo simulation) and compared simulated height in a spatial network with characteristics of the observed geographic height distribution of three historic cohorts of Swiss military conscripts (conscripted in 1884-1891; 1908-1910; and 2004-2009). RESULTS: Conscript height shows several characteristic features: (1) height distributions are overdispersed. (2) Conscripts from districts with direct inter-district road connections tend to be similar in height. (3) Clusters of tall and clusters of short stature districts vary over time. Autocorrelations in height between late 19th and early 21st century districts are low. (4) Mean district height depends on the number of connecting roads and on the number of conscripts per district. Using Monte Carlo simulation, we were able to generate these natural characteristics in an artificial society. Already 5% height information from directly connected districts is sufficient to simulate the characteristics of natural height distribution. Very similar observations in regular rectangular networks indicate that the characteristics of Swiss conscript height distributions do not so much result from the particular Swiss geography but rather appear to be general features of spatial networks. CONCLUSIONS: Spatial connectedness can affect height clustering in an artificial society, similar to that seen in natural cohorts of military conscripts, and strengthen the concept of connectedness being involved in the regulation of human height.

Biological maturation of youth athletes: assessment and implications.

The search for talent is pervasive in youth sports. Selection/exclusion in many sports follows a maturity-related gradient largely during the interval of puberty and growth spurt. As such, there is emphasis on methods for assessing maturation. Commonly used methods for assessing status (skeletal age, secondary sex characteristics) and estimating timing (ages at peak height velocity (PHV) and menarche) in youth athletes and two relatively recent anthropometric (non-invasive) methods (status-percentage of predicted near adult height attained at observation, timing-predicted maturity offset/age at PHV) are described and evaluated. The latter methods need further validation with athletes. Currently available data on the maturity status and timing of youth athletes are subsequently summarised. Selection for sport and potential maturity-related correlates are then discussed in the context of talent development and associated models. Talent development from novice to elite is superimposed on a constantly changing base-the processes of physical growth, biological maturation and behavioural development, which occur simultaneously and interact with each other. The processes which are highly individualised also interact with the demands of a sport per se and with involved adults (coaches, trainers, administrators, parents/guardians).

Developmental trajectories of anxiety and depression in early adolescence.

Adolescence is a period of heightened vulnerability for the onset of internalizing psychopathology. Characterizing developmental patterns of symptom stability, progression, and co-occurrence is important in order to identify adolescents most at risk for persistent problems. We use latent growth curve modeling to characterize developmental trajectories of depressive symptoms and four classes of anxiety symptoms (GAD, physical symptoms, separation anxiety, and social anxiety) across early adolescence, prospective associations of depression and anxiety trajectories with one another, and variation in trajectories by gender. A diverse sample of early adolescents (N = 1,065) was assessed at three time points across a one-year period. All classes of anxiety symptoms declined across the study period and depressive symptoms remained stable. In between-individual analysis, adolescents with high levels of depressive symptoms experienced less decline over time in symptoms of physical, social, and separation anxiety. Consistent associations were observed between depression and anxiety symptom trajectories within-individuals over time, such that adolescents who experienced a higher level of a specific symptom type than would be expected given their overall symptom trajectory were more likely to experience a later deflection from their average trajectory in other symptoms. Within-individual deflections in GAD, physical, and social symptoms predicted later deflections in depressive symptoms, and deflections in depressive symptoms predicted later deflections in GAD and separation anxiety symptoms. Females had higher levels of symptoms than males, but no evidence was found for variation in symptom trajectories or their associations with one another by gender or by age.

Understanding why children die in high-income countries.

Many factors affect child and adolescent mortality in high-income countries. These factors can be conceptualised within four domains-intrinsic (biological and psychological) factors, the physical environment, the social environment, and service delivery. The most prominent factors are socioeconomic gradients, although the mechanisms through which they exert their effects are complex, affect all four domains, and are often poorly understood. Although some contributing factors are relatively fixed--including a child's sex, age, ethnic origin, and genetics, some parental characteristics, and environmental conditions--others might be amenable to interventions that could lessen risks and help to prevent future child deaths. We give several examples of health service features that could affect child survival, along with interventions, such as changes to the physical or social environment, which could affect upstream (distal) factors.

A comparative study of production performance and animal health practices in organic and conventional dairy systems.

Health and production management strategies influence environmental impacts of dairies. The objective of this paper was to measure risk factors on health and production parameters on six organic and conventional bovine, caprine, and ovine dairy herds in southeastern Brazil over six consecutive years (2006-2011). The organic operations had lower milk production per animal (P ≤ 0.05), lower calf mortality (P ≤ 0.05), less incidence of mastitis (P ≤ 0.05), fewer rates of spontaneous abortions (P ≤ 0.05), and reduced ectoparasite loads (P ≤ 0.05) compared to conventional herds and flocks. Organic herds, however, had greater prevalence of internal parasitism (P ≤ 0.05) than conventional herds. In all management systems, calves, kids, and lambs had greater oocyte counts than adults. However, calves in the organic group showed lower prevalence of coccidiosis. In addition, animals in the organic system exhibited lower parasitic resistance to anthelmintics. Herd genetic potential, nutritive value of forage, feed intake, and pasture parasite loads, however, may have influenced productive and health parameters. Thus, although conventional herds showed greater milk production and less disease prevalence, future research might quantify the potential implications of these unreported factors.

Effect of integrated responsive stimulation and nutrition interventions in the Lady Health Worker programme in Pakistan on child development, growth, and health outcomes: a cluster-randomised factorial effectiveness trial.

BACKGROUND: Stimulation and nutrition delivered through health programmes at a large scale could potentially benefit more than 200 million young children worldwide who are not meeting their developmental potential. We investigated the feasibility and effectiveness of the integration of interventions to enhance child development and growth outcomes in the Lady Health Worker (LHW) programme in Sindh, Pakistan. METHODS: We implemented a community-based cluster-randomised effectiveness trial through the LHW programme in rural Sindh, Pakistan, with a 2 × 2 factorial design. We randomly allocated 80 clusters (LHW catchments) of children to receive routine health and nutrition services (controls; n=368), nutrition education and multiple micronutrient powders (enhanced nutrition; n=364), responsive stimulation (responsive stimulation; n=383), or a combination of both enriched interventions (n=374). The allocation ratio was 1:20 (ie, 20 clusters per intervention group). The data collection team were masked to the allocated intervention. All children born in the study area between April, 2009, and March, 2010, were eligible for enrolment if they were up to 2·5 months old without signs of severe impairments. Interventions were delivered by LHWs to families with children up to 24 months of age in routine monthly group sessions and home visits. The primary endpoints were child development at 12 and 24 months of age (assessed with the Bayley Scales of Infant and Toddler Development, Third Edition) and growth at 24 months of age. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT007159636. FINDINGS: 1489 mother-infant dyads were enrolled into the study, of whom 1411 (93%) were followed up until the children were 24 months old. Children who received responsive stimulation had significantly higher development scores on the cognitive, language, and motor scales at 12 and 24 months of age, and on the social-emotional scale at 12 months of age, than did those who did not receive the intervention. Children who received enhanced nutrition had significantly higher development scores on the cognitive, language, and social-emotional scales at 12 months of age than those who did not receive this intervention, but at 24 months of age only the language scores remained significantly higher. We did not record any additive benefits when responsive stimulation was combined with nutrition interventions. Responsive stimulation effect sizes (Cohen's d) were 0·6 for cognition, 0·7 for language, and 0·5 for motor development at 24 months of age; these effect sizes were slightly smaller for the combined intervention group and were low to moderate for the enhanced nutrition intervention alone. Children exposed to enhanced nutrition had significantly better height-for-age Z scores at 6 months (p<0·0001) and 18 months (p=0·02) than did children not exposed to enhanced nutrition. Longitudinal analysis showed a small benefit to linear growth from enrolment to 24 months (p=0·026) in the children who received the enhanced nutrition intervention. INTERPRETATION: The responsive stimulation intervention can be delivered effectively by LHWs and positively affects development outcomes. The absence of a major effect of the enhanced nutrition intervention on growth shows the need for further analysis of mediating variables (eg, household food security status) that will help to optimise future nutrition implementation design. FUNDING: UNICEF.

Development of BMI values of German children and their healthcare costs.

The aim of this study is to assess the association between different patterns of Body Mass Index (BMI) development from birth on and later healthcare utilisation and costs in children aged about 10 years based on two birth cohort studies: the GINIplus study (3287 respondents) and the LISAplus study (1762 respondents). Direct costs were estimated using information on healthcare utilisation given by parents in the 10-year follow-up. To meet this aim, we (i) estimate BMI-standard deviation score (BMIZ) trajectories using latent growth mixture models and (ii) examine the correlation between these trajectories and utilisation of healthcare services and resulting costs at the 10-year follow-up. We identified three BMI-trajectories: a normative BMIZ growth class (BMI development almost as in the WHO growth standards), a rapid BMIZ growth up to age 2 years class (with a higher BMI in the first two years of life as proposed by the WHO growth standards) and a persistent rapid BMIZ growth up to age 5 years class (with a higher BMI in the first five years of life as proposed by the WHO growth standards). Annual total direct medical costs of healthcare use are estimated to be on average €368 per child. These costs are doubled, i.e. on average €722 per child, in the group with the most pronounced growth (persistent rapid BMIZ growth up to age 5 years class).

Factors associated with physical growth of children during the first two years of life in rural and urban areas of Vietnam.

BACKGROUND: Differences between urban and rural settings can be seen as a very important example of gaps between groups in a population. The aim of this paper is to compare an urban and a rural area regarding child growth during the first two years of life as related to mother's use of antenatal care (ANC), breastfeeding and reported symptoms of illness. METHODS: The studies were conducted in two Health and Demographic Surveillance Sites, one rural and one urban in Hanoi, Vietnam. RESULTS: We found that children in the urban area grow faster than those in the rural area. There were statistical associations between growth and the education of the mother as well as household resources. There were positive correlations between the number of ANC visits and child growth. We also saw a positive association between growth and early initiation (first hour of life) of breastfeeding but the reported duration of exclusive breastfeeding was not statistically significantly related to growth. Reporting symptoms of illness was negatively correlated to growth, i.e. morbidity is hampering growth. CONCLUSIONS: All predictors of growth discussed in this article, ANC, breastfeeding and illness, are associated with social and economic conditions. To improve and maintain good conditions for child growth it is important to strengthen education of mothers and household resources particularly in the rural areas. Globalization and urbanization means obvious risks for increasing gaps not least between urban and rural areas. Improvement of the quality of programs for antenatal care, breastfeeding and integrated management of childhood illness are also needed in Vietnam.

Criteria and markers for protein quality assessment - a review.

Dietary proteins are found in animal products, plant products and single-cell organisms. Proteins are present in variable proportions in these different food sources and the different proteins also differ in their amino acid composition, dietary indispensable amino acid content and physico-chemical properties. Different criteria can be used to define dietary protein requirements and different markers can be used to assess nutritional protein quality according to the criteria used for protein requirement estimation. The current approach to determining protein requirements is related to nitrogen balance and the dietary indispensable amino acid score approach relates protein quality to the capacity of protein to allow reaching nitrogen balance by providing nitrogen and indispensable amino acids. A second approach considers more directly protein nitrogen utilization by the body and includes measurement of protein digestibility and of the efficiency of dietary nitrogen retention at maintenance or for protein deposition at the whole body level or in more specific body areas. Another approach is related to protein turnover and protein synthesis in relation to maintenance and/or efficiency for deposition or development (growth) at the whole body level or for different and more specific target tissues such as muscle or bone. Lastly, protein quality can also be evaluated from different markers used as risk factors for metabolic dysfunction and disorders related for instance to insulin resistance, diabetes and obesity or cardio-vascular disease. The accuracy and relevance of these different approaches is discussed regarding the capacity of the different protein sources (i.e. animal as meat, milk or eggs, legume as soya or pea, or cereal as wheat or rice) to satisfy protein requirements according to these different criteria and markers.

[The developmental changes in physiological cost of locomotion efforts in overweight boys]. / Rozwojowe zmiany kosztu wysilków lokomocyjnych u chlopców o nadmiernym otluszczeniu ciala.

INTRODUCTION: In obese children the aerobic capacity (maximal oxygen intake) is lower than in non-obese children, but lower ability to perform long-term efforts can also result from higher physiological cost (in comparison to normal weight children) during locomotion efforts. AIM OF THE STUDY: was to determine developmental changes in physiological cost of walks in boys with excessive level of body fat (F%) during puberty. MATERIAL AND METHODS: The study was conducted on 11 boys with excessive level of body fat (%F=26.82±2.89 % - GROUP O) and 14 with normal level of body fat (%F=12.51±2.35% - GROUP P). The boys performed the graded test and a few days later two submaximal walks (6 min each with a 4 min pause for rest between walks) on mechanical treadmill with different speed (3.6 km×h(-1) and 4.8 km×h(-1)) every two years (three series) beginning at the age about 10 years and finishing at the age of 13-14 years. RESULTS: The level of pulmonary ventilation (VE) and tidal volume (TV) were significantly higher in overweight boys, but breathing frequency (BF) was similar in both groups. With age, the economy of breathing was improved in both groups: pulmonary ventilation and tidal volume were increasing but BF was decreasing. The work intensity during walking, expressed as %VO2max and %HRmax, was higher in boys with excessive level of body fat and decreased with age. Total values of VO2 (l×min(-1)) were higher in the group of overweight boys, but relatively to body mass the values of VO2 were significantly lower in this group and with age the difference between groups was constant. CONCLUSIONS: The physiological cost of walking was higher in boys with excessive level of body fat in each test in comparison with non-obese boys. The difference between groups in level of physiological parameters increased with speed of walking. The physiological cost of walking decreased with age in both groups.

Medical instability and growth of children and adolescents with early onset eating disorders.

OBJECTIVE: Little is known about the physical burden of early onset eating disorders (EOEDs). Most published data on physical instability and growth in malnutrition come from specialist centres, or from the developing world where aetiology differs. The authors present data on physical status at presentation from population-based surveillance systems in the UK and Ireland. DESIGN: Prospective surveillance study. PARTICIPANTS: All suspected cases of EOED in children under 13 years of age reported by paediatricians and psychiatrists via the British Paediatric Surveillance System (BPSU) and Child and Adolescent Psychiatric Surveillance System (CAPSS) in the UK and Ireland from March 2005 to May 2006 (15 months). RESULTS: 208 cases were identified (24% reported by paediatricians). Median age was 11.8 years (IQR 1.74). 171 (82%) were female (78% premenarcheal and 60% prepubertal). 74% of males were prepubertal. 35% of cases had medical instability at presentation (60% bradycardia, 54% hypotension, 34% dehydration, 26% hypothermia). 52% of cases required admission at diagnosis (73% to a paediatric ward). 41% of cases with medical instability were not underweight, that is, they had body mass index (BMI) z-scores above -2.0 (2nd centile). Sensitivities for identifying medical instability with BMI z-score <-3 or 70% median BMI were 31% and 15%, respectively. Menarcheal status did not predict risk of medical instability. CONCLUSIONS: EOEDs present with severe levels of physical instability and frequently to paediatricians. As anthropological indices alone are poor markers for medical instability, clinical assessment is essential. Doctors providing care for children have a central role in both the recognition and management of EOEDs.

Children of low socioeconomic status show accelerated linear growth in early childhood; results from the Generation R Study.

OBJECTIVES: People of low socioeconomic status are shorter than those of high socioeconomic status. The first two years of life being critical for height development, we hypothesized that a low socioeconomic status is associated with a slower linear growth in early childhood. We studied maternal educational level (high, mid-high, mid-low, and low) as a measure of socioeconomic status and its association with repeatedly measured height in children aged 0-2 years, and also examined to what extent known determinants of postnatal growth contribute to this association. METHODS: This study was based on data from 2972 mothers with a Dutch ethnicity, and their children participating in The Generation R Study, a population-based cohort study in Rotterdam, The Netherlands (participation rate 61%). All children were born between April 2002 and January 2006. Height was measured at 2 months (mid-90% range 1.0-3.9), 6 months (mid-90% range 5.6-11.4), 14 months (mid-90% range 13.7-17.9) and 25 months of age (mid-90% range 23.6-29.6). RESULTS: At 2 months, children in the lowest educational subgroup were shorter than those in the highest (difference: -0.87 cm; 95% CI: -1.16, -0.58). Between 1 and 18 months, they grew faster than their counterparts. By 14 months, children in the lowest educational subgroup were taller than those in the highest (difference at 14 months: 0.40 cm; 95% CI: 0.08,0.72). Adjustment for other determinants of postnatal growth did not explain the taller height. On the contrary, the differences became even larger (difference at 14 months: 0.61 cm; 95% CI: 0.26,0.95; and at 25 months: 1.00 cm; 95% CI: 0.57,1.43) CONCLUSIONS: Compared with children of high socioeconomic status, those of low socioeconomic status show an accelerated linear growth until the 18th month of life, leading to an overcompensation of their initial height deficit. The long-term consequences of these findings remain unclear and require further study.

Competition with a host nestling for parental provisioning imposes recoverable costs on parasitic cuckoo chick's growth.

Chicks of the brood parasitic common cuckoo (Cuculus canorus) typically monopolize host parental care by evicting all eggs and nestmates from the nest. To assess the benefits of parasitic eviction behaviour throughout the full nestling period, we generated mixed broods of one cuckoo and one great reed warbler (Acrocephalus arundinaceus) to study how hosts divide care between own and parasitic young. We also recorded parental provisioning behaviour at nests of singleton host nestlings or singleton cuckoo chicks. Host parents fed the three types of broods with similar-sized food items. The mass of the cuckoo chicks was significantly reduced in mixed broods relative to singleton cuckoos. Yet, after the host chick fledged from mixed broods, at about 10-12 days, cuckoo chicks in mixed broods grew faster and appeared to have compensated for the growth costs of prior cohabitation by fledging at similar weights and ages compared to singleton cuckoo chicks. These results are contrary to suggestions that chick competition in mixed broods of cuckoos and hosts causes an irrecoverable cost for the developing brood parasite. Flexibility in cuckoos' growth dynamics may provide a general benefit to ecological uncertainty regarding the realized successes, failures, and costs of nestmate eviction strategies of brood parasites.