Short stature at school entry--an index of social deprivation? (The Wessex Growth Study)

Waist-to-height ratio is the best anthropometric predictor of hypertension: A population-based study with women from a state of northeast of Brazil

The WHO recommends the use of some anthropometric parameters as a screening resource for individuals under cardiometabolic risk. However, in the validation of these indicators, Brazilian women were not included. These women have different anthropometric profile compared to women who integrated the samples of the validation studies. We aimed to verify the accuracy of anthropometric indicators as a resource for the screening of women with hypertension. A cross-sectional study, with a probability sample of 3143 women (20-49 years) from the state of Alagoas (northeast of Brazil), was carried out. Hypertension was identified by systolic blood pressure (SBP) ≥140 mm Hg and/or diastolic BP ≥90 mm Hg and/or regular use of antihypertensive drugs. The anthropometric indicators analyzed were BMI, waist circumference, waist-to-hip ratio, waist-to-height ratio (WHtR), body fat percentage, and conicity index. The accuracy definition of the indicators and the identification of best cut-off points were carried out on the basis of ROC curve analysis and Youden index, respectively. The prevalence of hypertension was 21.8%. All indicators used in hypertension identification had area under the ROC curve (AUC) >0.5. The WHtR with cut-off point of 0.54 was the best performance indicator (AUC = 0.72; P < 0.05; sensitivity = 67%, specificity = 66%). The WHtR with cut-off point of 0.54 has constituted the most accurate indicator in the screening of women with hypertension. In the absence of specific studies and considering the largest ethnic proximity and environmental/epidemiological similarity, the findings now obtained can be extended to women of other Brazilian states, especially those in the Northeastern region.

Short Stature: Is It a Psychosocial Problem and Does Changing Height Matter?

Some proponents of recombinant human growth hormone (rhGH) treatment in growth hormone-sufficient children cite height, as an isolated physical characteristic, as being associated with psychosocial morbidity. Others question the reliability of the evidence underpinning the quality-of-life rationale for treatment as well as the bioethics of rhGH treatment. The following questions are addressed: (1) Is short stature an obstacle to positive psychosocial adjustment? and (2) Does increasing height with rhGH treatment make a difference to the person's psychosocial adaptation and quality of life? Three clinical case examples are used to illustrate the complexities associated with decision-making surrounding rhGH use.

The adverse effect profile of oral azathioprine in pediatric atopic dermatitis, and recommendations for monitoring

Background

Azathioprine is efficacious in the treatment of severe childhood atopic dermatitis; however, robust data on adverse effects in this population are lacking.

Objective

We sought to assess adverse effects of azathioprine treatment in a pediatric atopic dermatitis cohort, and make recommendations for monitoring based on these data.

Methods

Blood test results for all 82 children prescribed oral azathioprine for atopic dermatitis in our department between 2010 and 2012 were collated prospectively, and clinical notes were reviewed retrospectively.

Results

Mean age at commencing azathioprine was 8.3 years (SEM 0.4). Mean maximum doses were 2.4 mg/kg (SEM 0.1) and 1.5 mg/kg (SEM 0.1) for normal and reduced serum thiopurine-S-methyltransferase levels, respectively. Adverse effects on blood indices occurred in 34 of 82 patients (41%), with pronounced effects in 18 of 82 (22%) after a median time of 0.4 years. Two patients stopped therapy as a result of abnormal blood indices. Clinical adverse effects occurred in 16 of 82 (20%), two resulting in cessation of therapy. Incidence of adverse effects was unaffected by age, sex, thiopurine-S-methyltransferase level, and drug dose on multivariate regression.

Limitations

Comparison with other studies is limited by varying definitions of adverse effects.

Conclusion

Oral azathioprine was associated with few pronounced adverse effects for the duration of use and dosage in this cohort. Recommendations for monitoring are made.

Socioeconomic differences in childhood length/height trajectories in a middle-income country: a cohort study

BACKGROUND

Socioeconomic disadvantage is associated with shorter adult stature. Few studies have examined socioeconomic differences in stature from birth to childhood and the mechanisms involved, particularly in middle-income former Soviet settings.

METHODS

The sample included 12,463 Belarusian children (73% of the original cohort) born in 1996-1997, with up to 14 stature measurements from birth to 7 years. Linear spline multi-level models with 3 knots at 3, 12 and 34 months were used to analyse birth length and growth velocity during four age-periods by parental educational achievement (up to secondary school, advanced secondary/partial university, completed university) and occupation (manual, non-manual).

RESULTS

Girls born to the most (versus least) educated mothers were 0.43 cm (95% confidence interval (CI): 0.28, 0.58) longer at birth; for boys, the corresponding difference was 0.30 cm (95% CI: 0.15, 0.46). Similarly, children of the most educated mothers grew faster from birth-3 months and 12-34 months (p-values for trend ≤ 0.08), such that, by age 7 years, girls with the most (versus least) educated mothers were 1.92 cm (95% CI: 1.47, 2.36) taller; after controlling for urban/rural and East/West area of residence, this difference remained at 1.86 cm (95% CI: 1.42, 2.31), but after additionally controlling for mid-parental height, attenuated to 1.10 cm (95% CI: 0.69, 1.52). Among boys, these differences were 1.95 cm (95% CI: 1.53, 2.37), 1.89 cm (95% CI: 1.47, 2.31) and 1.16 cm (95% CI: 0.77, 1.55), respectively. Additionally controlling for breastfeeding, maternal smoking and older siblings did not substantively alter these findings. There was no evidence that the association of maternal educational attainment with growth differed in girls compared to boys (p for interaction = 0.45). Results were similar for those born to the most (versus least) educated fathers, or who had a parent with a non-manual (versus manual) occupation.

CONCLUSIONS

In Belarus, a middle-income former Soviet country, socioeconomic differences in offspring growth commence in the pre-natal period and generate up to approximately 2 cm difference in height at age 7 years. These associations are partly explained by genetic or other factors influencing parental stature.

TRIAL REGISTRATION

Current Controlled Trials: NCT01352247 assigned 9 Sept 2005; ClinicalTrials.gov. Identifier: NCT01561612 received 20 Mar 2012.

Child undernutrition in affluent societies: what are we talking about?

In this paper we set out to explore the prevalence of child undernutrition found in community studies in affluent societies, but a preliminary literature review revealed that, in the absence of a gold standard method of diagnosis, the prevalence largely depends on the measure, threshold and the growth reference used, as well as age. We thus go on to explore describe the common clinical ‘syndromes’ of child undernutrition: wasting, stunting and failure to thrive (weight faltering) and how we have used data from two population-based cohort studies, this paper to explore how much these different ‘syndromes’ overlap and the extent to which they reflect true undernutrition. This analysis revealed that when more than one definition is applied to the same children, a majority are below the lower threshold for only one measure. However, those with both weight faltering and low BMI in infancy, go on in later childhood to show growth and body composition patterns suggestive of previous undernutrition. In older children there is even less overlap and most children with either wasting or low fat seem to be simply growing at one extreme of the normal range. We conclude that in affluent societies the diagnosis of undernutrition is only robust when it relies on a combination of both, that is decline in weight or BMI centile and wasting.

Socioeconomic inequalities in height, leg length and trunk length among children aged 6.5 years and their parents from the Republic of Belarus: evidence from the Promotion of Breastfeeding Intervention Trial (PROBIT)

BACKGROUND

Lower socioeconomic position is associated with shorter stature, in particular shorter leg length, but the magnitude of these associations in non-Western countries has received little attention.

AIM

To examine socioeconomic differentials in height, leg and trunk length in 6.5 year olds from the Republic of Belarus and compare these to differentials in parental height.

METHODS

Multivariable linear regression was used to examine associations in a cohort of 13 889 children.

RESULTS

Children from non-manual households were 1.0 cm (95% confidence interval: 0.7-1.3 cm) taller than those from manual households. Mothers and fathers from non-manual backgrounds were 0.7 cm (0.5-0.8) and 1.8 cm (1.6-2.0) taller than those from manual backgrounds, respectively. Associations with higher parental educational attainment were similar. The magnitudes of the associations of socioeconomic position with leg length were similar to those with trunk length. Adjusting for mid-parental height and number of older siblings attenuated associations markedly.

CONCLUSIONS

In Belarus, similar socioeconomic differentials in height were observed in both children and their parents. Among children, height differentials were partly explained by mid-parental height and number of older siblings. Leg length was not a more sensitive indicator of childhood socioeconomic conditions than trunk length.

Adolescents with mild stunting show alterations in glucose and insulin metabolism

Purpose. To evaluate glucose and insulin profiles in adolescents with mild stunting and overweight in order to assess the possibility of increased predisposition to diabetes. Subjects and Methods. The study population consisted of 66 pubertal adolescents classified as mildly stunted (height-for-age z scores ≥-2 and <-1) or of normal stature, as well as overweight (body mass index ≥85th percentile) or normal weight. Beta-cell function and insulin resistance were evaluated according to the homeostasis model assessment (HOMA). Results. In the group with mild stunting, glucose, insulin, and HOMA-IR levels were significantly higher in overweight adolescents compared with those of normal weight, whereas HOMA-B levels were significantly lower. Adolescents with mild stunting showed significantly higher accumulations of body and abdominal fat than their normal stature counterparts. Conclusions. The presence of mild stunting was associated with higher levels of glucose and insulin, diminished function of beta cells, and increased insulin resistance. These results reinforce the need for intervention in adolescents with mild stunting.

Influência do déficit de estatura nos desvios nutricionais em adolescentes e pré-adolescentes

OBJETIVO: Avaliar a influência do déficit estatural nos desvios nutricionais em pré-adolescentes e adolescentes de baixa renda. MÉTODOS: Calculou-se o Índice de Massa Corporal a partir do peso e da estatura de alunos da rede pública entre 4 e 8ª séries. Foram utilizadas as tabelas do National Center for Health Statistics de 2000 para crianças e adolescentes e foi considerado excesso de peso Índice de Massa Corporal/Idade>P85 e déficit de peso Índice de Massa Corporal/Idade <P5. Déficit estatural foi classificado quando estatura/idade foi menor que -1 desvio-padrão. Foram comparadas as proporções de baixo peso e excesso de peso nos grupos com e sem déficit estatural, de acordo com sexo e faixa etária. RESULTADOS: Foram avaliados 3 766 jovens sendo 50,4% do sexo feminino. A média de idade foi de 12,8, desvio-padrão de 2,0 anos, sem diferença significante entre os grupos. No grupo com déficit de estatura, observou-se que o excesso de peso é mais prevalente entre os mais velhos. Naqueles sem déficit de estatura a distribuição por idades foi semelhante para as três classificações de Índice de Massa Corporal/Idade. A distribuição por sexo mostra que o excesso de peso no grupo com déficit de estatura foi mais acentuada entre as meninas (76,1%) enquanto que no grupo com estatura normal a diferença foi mínima entre os sexos (4,4%). CONCLUSÃO: Na presença do déficit de estatura, o excesso de peso foi mais prevalente nos maiores de 12 anos e entre o sexo feminino. Os meninos sem déficit de estatura mostraram uma proporção maior de excesso de peso em relação aos com déficit de estatura.

Infusing neuroscience into the study and prevention of drug misuse and co-occurring aggressive behavior

The etiology of behavioral precursors to substance misuse and aggression is viewed from the perspective of a developmental, multifactorial model of complex disorders. Beginning at conception, genetic and environmental interactions have potential to produce a sequence of behavioral phenotypes during development that bias the trajectory toward high-risk outcomes. One pathway is theorized to emanate from a deviation in neurological development that predisposes children to affective and cognitive delays or impairments that, in turn, generate dysregulatory behaviors. The plasticity of these neurobiological systems is highly relevant to the prevention sciences; their functions are reliant upon environmental inputs and can be altered, for better or for worse, contingent upon the nature of the inputs. Thus, social contextual factors confer significant influence on the development of this neural network and behavioral outcomes by increasing risk for, or protecting (1) against, dysregulatory outcomes. A well-designed intervention can exploit the brain's plasticity by targeting biological and social factors at sensitive time points to positively influence emergent neurobiological functions and related behaviors. Accordingly, prevention research is beginning to focus on perturbations in developmental neural plasticity during childhood that increase the likelihood of risky behaviors and may also moderate intervention effects on behavior. Given that the more complex features of neurobiological functions underlying drug misuse and aggression (e.g., executive cognitive function, coping skills, affect regulation) do not coalesce until early adulthood when prefrontal-limbic brain networks consolidate, it is critical that mechanisms underlying developmental risk factors are identified. An empirically driven prevention approach, thus, may benefit from consideration of (i) the type, effect, and developmental timing of the environmental impact on the brain, and (ii) the type and effect on brain function, and developmental timing of the intervention. This translational approach promises to eventually offer some direction for the design of effective interventions to prevent drug misuse and concomitant aggression.

Residential area as proxy for socio-economic status, paediatric mortality and birth weight in Lusaka, Zambia

Systems of socio-economic classification comparable to the Registrar General's Social Classification or post codes are not readily available in many developing countries. Thus health data from developing countries are usually presented without a refined geographical focus. The hierarchical urban residential classification system in Zambia was used as a socio-economic proxy to explore the relationship with mass measures of paediatric health in Lusaka, Zambia. This study shows that the Zambian urban residential classification system appears to be a valid proxy of socio-economic status, revealing residential gradients with respect to birth weight and paediatric mortality rates in Lusaka.

Does financial disadvantage at older ages eliminate the potential for better health?

OBJECTIVE

Taller adult stature reflects early life advantages and is an indicator of improved economic and health outcomes, and thus the potential for better health, including reduced depression risk. As inadequate retirement pension provision is an increasing concern, we investigated whether health potential (indicated by height) was realised among those experiencing financial disadvantage in later life.

DESIGN, SETTING AND PARTICIPANTS

Cross-sectional study of the population in England aged over 50 years and not resident in an institution. Participants (n = 9106) were members of the English Longitudinal Study of Ageing.

MAIN OUTCOME MEASURE

Depression assessed using the eight-item Center for Epidemiological Studies Depression Scale.

RESULTS

Stratification by the lowest quintile of the net financial assets distribution defined adversity, and stature was dichotomised at the shortest quintile of height (sex standardised). After adjustment for sex, qualifications, occupation type, whether currently employed, age, ethnic origin and chronic illness, taller stature was associated with a statistically significant reduced risk of depression with an odds ratio of 0.7 (95% confidence interval 0.6 to 0.9) among those without financial disadvantage. No protection against depression was associated with taller stature among those with financial disadvantage (odds ratio 1.0; 95% confidence interval 0.8 to 1.3). Interaction testing confirmed effect modification by financial disadvantage for the association of height with depression (p = 0.005).

CONCLUSIONS

Although taller stature, indicating favourable childhood conditions, is associated with a decreased risk of depression, this benefit is eliminated by financial disadvantage at older ages. Adequate financial provision for older people is required to maximise the health potential imparted by beneficial conditions in earlier life.

Economic disadvantage modifies the association of height with low mood in the US, 2004: the disappointment paradox

INTRODUCTION

Taller stature is associated with greater health potential reflected by reduced risks for coronary heart disease (CHD) and depression. Previous studies demonstrated that the reduced CHD and depression risks associated with tall stature were eliminated by financial disadvantage in adult life.

HYPOTHESIS

The reduced risk of depression, defined as low mood, associated with taller stature is eliminated by adult financial adversity. This study also attempts to replicate earlier findings, that the reduced risk of CHD associated with taller stature is eliminated by adult financial adversity.

METHODS

The Behavioral Risk Factor Surveillance System is an ongoing survey of the adult population of the US conducted by state health departments and the Centers for Disease Control and Prevention, providing a representative sample of 45,210 adults resident in USA in 2004 with data on low mood and CHD. Low mood was defined by self-reported low mood for more than 15 days in the previous month and CHD by a diagnosis of angina or coronary heart disease. Short stature was defined as the lower 20% of sex-standardised heights and economic disadvantage as household income below $15,000 per annum.

RESULTS

Tall stature was associated with a statistically significant reduced risk for low mood in the entire population. After stratification by economic disadvantage, taller individuals in the higher income stratum maintained a statistically significant reduced risk of low mood, with an odds ratio (and 95% confidence interval) of 0.90 (0.90, 0.91) after adjustment for potential confounding factors and application of the survey weighting. In contrast, taller stature represented a raised risk for low mood in the lower income stratum, with a statistically significant odds ratio of 1.27 (1.26, 1.28) with weighting. This effect modification was confirmed by interaction testing, producing an odds ratio for interaction of 1.39 (1.37, 1.39; p<0.001). This phenomenon was most profound among white males, with an odds ratio for interaction of 2.20 (2.16, 2.25). Effect modification by economic disadvantage was also observed for the association of height with CHD, producing an odds ratio for interaction of 1.57 (1.56, 1.59; p<0.001).

CONCLUSIONS

Although taller stature indicates better heath potential in terms of low mood and CHD, this potential is eliminated by economic disadvantage in later life. Indeed, taller stature is associated with an increased risk among those who experience economic disadvantage. Possible explanations are that childhood adversity reducing height may confer resilience against some forms of adult adversity. Alternatively, as taller stature signals greater childhood advantage, then financial adversity may represent a form of disappointment among this group: the disappointment paradox.

Duration of poverty and child health in the Quebec Longitudinal Study of Child Development: longitudinal analysis of a birth cohort

OBJECTIVES

The objective of this study was to examine the relationship between duration of poverty and the health of preschool children in the Quebec Longitudinal Study of Child Development birth cohort.

METHODS

Data from the Quebec Longitudinal Study of Child Development for 1950 children who were followed annually up to age 3 years were analyzed. Poverty was defined as having an income below the low-income cutoff from Statistics Canada. Five health indicators were examined: asthma attacks, infections, growth delay, a cumulative health-problems index, and maternal perception of the child's health. The association between duration of poverty and child health was explored with logistic regression modeling controlling for child and mother characteristics, including the mother's level of education, social support, and physical violence.

RESULTS

In this birth cohort, 13.7% (268) 3-year-old children from the Quebec Longitudinal Study of Child Development experienced intermittent poverty since birth (1-2 episodes), and another 14.4% (280) experienced chronic poverty (3-4 episodes). Children from families with chronic poverty had more frequent asthma attacks and had a higher cumulative health-problems index score, whereas children with intermittent poverty were more often perceived to be in less than very good health by their mothers. These associations remained statistically significant when controlling for child and mother characteristics. No association was observed between duration of poverty and infections or growth delay.

CONCLUSIONS

Chronic poverty affects a large number of children and has negative consequences for preschool children's health, although universal health care is available. The effects of chronic poverty may vary according to different health indicators and the age of the child.

Does height modify the risk of angina associated with economic adversity?

Adult height partly reflects childhood exposures, and we hypothesise that some exposures impairing growth may also increase susceptibility to coronary heart disease--angina pectoris (angina)--risks, such that shorter adults may be more susceptible to some exposures in adulthood that are risks for heart disease. This hypothesis is tested among all adults who participated in the National Health Interview Survey (USA), 1997-2000 [The National Health Survey, 1997-2000. Data file documentation, National Health Interview Survey (machine-readable data file and documentation). National Center for Health Statistics, Hyattsville, Maryland, ]. In the entire study population, height was negatively associated with angina and after adjustment for potential confounding factors; the odds ratio (and 95% confidence interval) for angina risk associated with the tallest height fifth compared with the shortest fifth is 0.77 (0.97, 0.88). The association of low income (less than US 20,000 dollars) with angina was assessed separately in each of five height strata defined by fifths of the height distribution. The magnitude of this association is lower in the shortest than the tallest height fifth, with odds ratios of 1.18 and 1.60, respectively (effect modification). The unexpected results may be explained by the following: childhood adversity resulting in shorter stature may confer resilience against adult economic adversity; the relative disadvantage of low income may be perceived more keenly by those of taller stature thereby increasing stress and thus disease risk; or health-promoting characteristics associated with taller stature may be less effective in the face of adult economic adversity in the low-income group.

Understanding the dimensions of socioeconomic status that influence toddlers' health: unique impact of lack of money for basic needs in Quebec's birth cohort

STUDY OBJECTIVES

To examine the unique impact of financial difficulties as measured by a lack of money for basic needs on the occurrence of health problems between the ages of 17 and 29 months, controlling for mother's level of education and neonatal health problems.

DESIGN AND PARTICIPANTS

Analyses were performed on the 29 month data of the Quebec longitudinal study of child development. This longitudinal study followed up a birth cohort annually. Interviews were conducted in the home with the mother in 98.8% of cases. This information was supplemented with data from birth records. At 29 months, the response rate was 94.2% of the initial sample (n = 1946). The main outcome measures were mothers' report of acute health problems, asthma episodes, and hospitalisation as well as growth delay and a composite index of health problems (acute problems, asthma attack, growth delay).

MAIN RESULTS

Children raised in a family experiencing a serious lack of money for basic needs during the preceding year were more likely to be reported by their mothers as presenting acute health problems, a growth delay, two or more health problems, and to have been hospitalised for the first time within the past few months as compared with babies living in a family not experiencing a lack of money for basic needs regardless of the mother's level of education and of neonatal health problems.

CONCLUSION

Financial difficulties as measured by a lack of money for basic needs have a significant and unique impact on toddlers' health.

Endocrine profile and physical stature of children with Perthes disease

Children with Perthes disease have been thought to be of smaller stature than their peers. No reproducible evidence exists to demonstrate an endocrinopathy as the cause. This study reviewed 139 children with Perthes disease. Height and weight were recorded and compared with standardized growth charts. A blood sample was analyzed for thyroid stimulating hormone (TSH), thyroxin (T4), and insulin-like growth factor 1 (IGF1). Two urine samples were collected at 8 am and 8 pm within 24 hours. From these a cortisol/creatinine ratio was calculated. The results were compared with those from 40 healthy matched controls. No significant differences were found between the study or control children for levels of TSH, T4, IGF1, or cortisol. Review of the height and weight results revealed that the study children were of normal body habitus compared with the general pediatric population and do not undergo a period of growth acceleration following the active stages of the disease.

Social inequalities and children's height in Trinidad and Tobago

OBJECTIVE

The aim of the study was to report the association of socio-economic factors with child's height.

DESIGN

Cross-sectional study based on a representative national sample of government schools.

SETTING

Trinidad and Tobago in 1999.

SUBJECTS

A total of 2608 boys and girls mean age 5.8 y, range 4.38-6.99 y and 3080 mean age 8.6 y, range 7.00-10.44 y olds.

OUTCOME

Measurement of height and a questionnaire completed by parents. In the analysis height was expressed as standard deviation scores (s.d.s.) based on the British height curves (1990) or height below -1.5 s.d.s.

RESULTS

Ethnicity, parental heights, birthweight, maternal age at child's birth and number of children in the family were the main factors associated with children's height. Lack of piped water supply in the home was the only socio-economic factor consistently associated with height (mean difference in s.d.s. adjusted only for age group, gender and ethnicity -0.192, 95% CI -0.257 to -0.127 and in addition adjusted for the variables listed above -0.080, 95% CI -0.141 to -0.019). Parental education, household overcrowding and employment status were weakly associated with height in the partially adjusted model only. Analysis of severe growth failure gave similar results.

CONCLUSION

The impact of socio-economic factors on height is marginal in Trinidad and Tobago. As socio-economic factors may have an impact on a broad range of health indicators, height and rates of undernutrition should not be used as sole criteria for assessing progress in decreasing health differentials caused by social inequalities.

Body mass index in male and female children with infantile autism

Morphometry, the measurement of forms, is an ancient practice. Recently, evidence has grown to support the notion that aberrant neurodevelopment may play a role in the pathophysiology of autism. Is the body, like the brain, affected by abnormal development in these patients? The aim of this study was to evaluate body mass index (BMI) of children with infantile autism, by comparing the BMI of 117 children with infantile autism with the corresponding BMI percentiles in an age- and sex-matched reference population. The BMI distribution of the male, but not female, children with infantile autism was significantly lower than that of the age-matched reference population. There was no evidence that BMI was associated with intelligence or socioeconomic status among children with infantile autism.

The importance of neurobiological research to the prevention of psychopathology

There is both a biological and environmental component to the neural substrates for various forms of psychopathology. Brain dysfunction itself not only constitutes a formidable liability to psychopathology, but also has an impact on environmental and social responses to the individual, compounding the risk for an adverse outcome. Environmental conditions, such as social and physical stimulus deprivation, poverty, traumatic stress, and prenatal drug exposure, can further compromise brain function in the context of existing liabilities. The relationship between genetic and environmental processes is interactive, fluid, and cumulative in their ability to influence an individual's developmental trajectory and alter subsequent behavioral outcomes. Given the codependent relationship between these processes, brain function is now believed to be malleable via manipulations of the environment in ways that may decrease liability for psychopathology. Research that explores these relationships and ways in which interventions can redirect this developmental track may substantially advance both the science and practice of prevention. Studies attempting to isolate the neurobiological effects of socioenvironmental factors are reviewed, implications for intervention strategies are discussed, and a future research agenda is proposed to provide greater insight into specific brain-environment relationships. Armed with this knowledge, prevention scientists may eventually design programs that directly target these effects to reverse or attenuate negative outcomes.

Does height influence progression through primary school grades?

AIM

To examine the relation between a child's height and grade progression in primary school.

METHODS

Height was measured in a representative cross sectional sample of children from 24 primary schools in Victoria in late 1997. Height measurements were transformed to standardised scores using Cole's "LMS" method to allow for comparison across ages and genders. Children within each grade were divided into three equal groups based on age (youngest third, middle third, oldest third), again to allow for cross age comparison.

RESULTS

A total of 2848 children aged 5-12 years (51% male) were included, with approximately 400 children in each of the seven grades from preparatory to grade 6. Analysis of variance showed a significant relation overall between age and height, with a sequential decrease in height from the youngest to the oldest third. When genders were considered separately, the relation remained significant for boys but not for girls. A total of 133 children (66% male) repeated a grade in primary school. When this group of grade repeaters was removed from the sample, analysis of variance showed no significant relation between standardised height score and age tertile for boys. Although birth weight category and maternal education were independent predictors of height scores overall, they did not appear to influence decisions to retain pupils in grades.

CONCLUSIONS

Older boys within grades, notably those who have repeated a grade, are shorter than their peers. Decisions to retain pupils, particularly boys who are experiencing school difficulties, may be influenced by their height.

The strengths and limitations of parental heights as a predictor of attained height

Mid-parental heights are widely used to help assess an individual child's growth. However, the methods in use vary, and most make no allowance for extremes of parental height. This study aimed to examine the actual distribution of parental heights in a survey population and the relation with their children's heights. The heights of 419 representatively sampled children aged 8-9 years were compared with their reported mid-parental heights, all expressed as standard deviation scores (SDS). These confirmed previous predictions that 90% of the children's heights would fall within 1.5 SDS (approximately two centile spaces) of their mid-parental heights. However, where parents were unusually tall or short, their children were relatively less tall or short, respectively, and the mid-parental height was a poor predictor of attained height. A simple calculator for expected height centile is described that automatically adjusts for this regression to the mean. Of 13 children below the second centile for height, eight were within two centile spaces (90% range) of their mid-parental height SDS. However, when allowance was made for regression to the mean, only three of 13 were within the 90% range. Although mid-parental height provides a useful guide to expected height centile for children and parents of average stature, it can be misleading when used to assess short children.

[Risk factors in the occurence of short stature of preschool children]

A case-control study was conducted to know the magnitude of the effect of main risk factors for short stature of pre-school children in a city in São Paulo State, in 1995. An anthropometric survey carried out with all children (1201) attending public pre-school classes was used to select the case and the control groups. It was selected a random sample of 165 children among those with stature/age (-1 z score (case) and another sample of 165 among those with stature/age ( +1 z score (control). The mothers or persons responsible for these children were interviewed in order to obtain information on demographic, maternal and socio-economic variables. The multiple logistic hierarchical analysis showed the following variables as associated with pre school children's short stature: mother's educational level (OR = 2,1; CI: 1,1-3,8); per capita family income (0,5 SM (OR = 3,4; CI: 1,5-8,0); number of persons in the house (6 (OR = 3,7; CI: 1,5-9,0); number of domestic equipment (1 (OR = 4,4; CI: 1,8-10,7 ); birth length <48 cm (OR = 7,4; CI: 2,3-23,7 ), mother's stature ( 156,6 cm (OR = 5,9 CI 3,1-11,0) and father's stature (169,5 cm (OR = 4,2; CI: 2,1-8,6). We found that even in a population of preschool children without nutritional deficiency (as measured by the usual anthropometric index) it is possible to observe the effect of socio economic variables in children stature.