Are short normal children at a disadvantage? The Wessex growth study

Short normal stature and psychosocial disadvantage: a critical review of the evidence

Physicians and parents alike are under increasing pressure to identify and to treat short stature, but intervention implies the presence of some pathology, physical or psychological, that can be corrected. Where there is true GH deficiency, the argument for replacement is uncontroversial. It is less compelling where GH 'insufficiency' is diagnosed. In the case of the short, but otherwise normal, child the indications for therapy are even less clear. Short stature, per se, is clearly not a disease, in spite of the perception by some practitioners that the rate of growth of such children is abnormal. Short stature is, however, commonly perceived to be associated with social and psychological disadvantage, yet many of these misperceptions about short stature can be challenged. A critical review of the literature pertaining to the psychosocial correlates of short stature uncovers much flawed evidence. Most importantly, the belief, widely held by paediatricians, that short children are likely to be significantly disadvantaged, has been founded largely on data from clinic-referred samples. In such studies, children with real (or perceived) behavioural or academic problems are likely to be overly represented. Publications arising from such studies, however, inevitably lead to an increase in the demand for treatment both from and for those who previously had no such concern. In contrast, data from a well controlled, prospective population-based study suggest the essential normality of the short normal child. Parents and children alike should be reassured by these findings. In the absence of clear pathology, physical or psychological, GH therapy for short but otherwise normal children must therefore, in most cases, be deemed cosmetic, raising issues as to the ethics of so-called "plastic endocrinology".

Obesity and abdominal fatness associated with undernutrition early in life in a survey in Rio de Janeiro

BACKGROUND

Undernutrition early in life has been associated with chronic diseases and obesity among adults. Our study tested the hypothesis by examining the association between low stature, a marker of early poor nutrition, with obesity and abdominal fatness among adults.

METHODS

A population-based survey was conducted in 1996, among 2040 households, with a non-response rate of 11.2%. Weight, height, waist and hip circumference, and skinfolds were measured at home.

RESULTS

Age-adjusted prevalence of body mass index (BMI) greater than 25 kg/m2 was 32% more frequent among adult men, and 60% more frequent among adult women, comparing the first to the fourth quintile of height. A J-shaped curve describes the association between weight and the sum of skinfolds with stature after adjusting for confounding by age, energy intake, physical activity, smoking, age at menarche, and race. The adjusted odds ratio of obesity (BMI>30 kg/m2) for short stature, compared to normal stature, was 1.57 with a 95% confidence interval (CI) = 0.90-2.71 among men and 1.84 with a 95% CI=1.10-3.06 among women. Short stature was associated with the risk of abdominal fatness only among women, with an odds ratio=1.77; 95% CI=1.10-2.83.

CONCLUSIONS

Increased risk of obesity and abdominal fatness among women of short stature, a marker for undernutrition early in life, was not explained by racial and socio-economic conditions, energy intake or age at menarche.

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.

Is short stature a handicap? A comparison of the psychosocial functioning of referred and nonreferred children with normal short stature and children with normal stature

OBJECTIVES

Normal short stature (NSS), defined as height below the 5th percentile for age and sex norms that is not due to illness, hormonal deficiency, or part of a dysmorphic syndrome, has been thought to have a deleterious effect on psychosocial functioning based on observations of referred populations. Recent studies of nonreferred children with NSS, however, have demonstrated normal function. This study directly compared the psychosocial functioning of referred children with NSS, nonreferred children with NSS, and children with normal stature.

STUDY DESIGN

Participants, 90 children (46 boys, 44 girls) between 6 and 12 years of age (mean, 9. 6 years), were administered intelligence and achievement tests. Parents and teachers assessed adaptive and problem behaviors. Family adaptability and cohesiveness were measured.

RESULTS

Intelligence and achievement for referred and nonreferred children with NSS were average. Referred children with NSS were reported to have more externalizing behavior problems and poorer social skills than nonreferred children with NSS and children in the control group. Family adaptability and cohesiveness were comparable across groups.

CONCLUSIONS

Children with NSS have normal psychosocial function, and results suggest that externalizing behavior problems, attention problems, and poor social skills in children referred to clinics for NSS are inappropriately attributed to short stature.

Behavioural and cognitive associations of short stature at 5 years

OBJECTIVES

To determine the extent to which childhood short stature is associated with cognitive, behavioural and chronic health problems, and whether these problems could be attributed to recognized adverse biological, psychosocial or psychological factors.

METHODOLOGY

At their first antenatal session, 8556 women were enrolled in a prospective study of pregnancy. When their children were 4 and 6 years of age, mothers completed a detailed questionnaire concerning their child's health and behaviour. A Peabody Picture Vocabulary Test-Revised (PPVT-R) was completed by the child at 5 years of age. Z scores were used to categorize height measurements in 3986 children. The relationship of these height categories with the child's health, and behavioural and cognitive problems was then examined.

RESULTS

No association was found between height and symptoms of chronic disease or behaviour problems in boys or girls. On the unadjusted analysis, mean PPVT-R scores were significantly lower in boys with heights < 3 percentile and 3-< 10 percentile compared with study children between 10 to 90 percentile (P < 0.01). Scores were similarly significantly lower in girls with heights < 3 percentile and 3-10 percentile (P = 0.01). Even after adjusting for psychosocial and biological confounders, short stature remained a significant predictor for lower PPVT-R scores in both boys and girls, although height only accounted for 1.1% of the variance in scores in boys and 0.5% of the variance in PPVT-R scores in girls. Psychosocial factors had a greater role than height in determining PPVT-R scores at 5 years of age.

CONCLUSIONS

These findings suggest a significant, though small, association between height and PPVT-R scores at 5 years of age, independent of psychosocial disadvantage and known biological risk factors.

Threats to validity in the longitudinal study of psychological effects: the case of short stature

In all studies of health-related problems and their effects on well-being, research design issues threaten to compromise the validity of findings. This is particularly so in a longitudinal study, essentially stemming from the tension between maintaining participant compliance and retaining investigator objectivity. Such a tension may be exacerbated where measures of dependent variables such as self-esteem are used alongside the collection of physical data which is essential to the study, as in research into the psychological effects of short stature on children and young people. In this paper one particular project, the Wessex Growth Study, is used to illustrate the common threats to validity, both internal and external, of such research, and to consider future improvements in design. The Wessex Growth Study, set up in 1986, was designed to overcome some of the methodological problems found in earlier research with short stature children. It is following the growth and psychological development through their school years of a cohort of short children (below third centile for height when first identified) and case-matched controls (10th-90th centiles) recruited at school entry (ages 5/6). Findings have generally found only small differences between short and average height children. Though these results so far have mainly been presented cross-sectionally, the young people involved are followed up at 6-monthly intervals for height and other data to be collected, and thus to some extent the study also has the advantages and problems of a longitudinal research design. Using Campbell and Stanley's criteria this article makes clear the strain on both internal and external validity in the study, but argues that these problems are to some extent inherent in all longitudinal psychological research, and are outweighed in the present research by the collection of data on short stature which would not otherwise be available. Future data collection within the study will introduce further improvements in design.

Assessment of stature in children with orofacial clefting

PURPOSE

To assess stature in children with orofacial clefting to determine whether this population is at risk for short stature and if growth failure is caused by hypothalamic-pituitary dysfunction or if it is related to age, sex, or type of cleft.

DESIGN

Cross-sectional.

METHODS

All children 3 to 12 years old with nonsyndromic orofacial clefts who were evaluated as outpatients were measured; those who demonstrated growth failure were to have an evaluation of their hypothalamic-pituitary function. Data were also collected on sex, age, and type of cleft.

RESULTS

Children with orofacial clefting had significantly more growth failure than the general population (p < 0.005). The parents of four of the five children with growth failure refused further evaluation because "no one else was ever concerned about my child's height."

CLINICAL IMPLICATIONS

The high rate of growth failure in this population emphasizes the need for precise growth assessment of children with orofacial clefting. Growth failure should not be ignored or minimized in populations of children having other significant health care problems.

Rises in schoolchildren's anthropometry: what do they signify in developed and developing populations?

Recent reports indicate continuing rises in the height and weight of schoolchildren in both developed and developing populations. Also indicated are increases in the body mass index of children, and of adults, despite all public health warnings to the contrary, as well as personal desires of huge proportions of children, and of adults, to be slim. A little researched question concerns which level of schoolchildren's growth is consistent in later life with least occurrence of degenerative diseases. In developing populations, lack of knowledge prevails regarding the current and future health of the large proportions, and huge numbers, of schoolchildren who, judging from Western anthropometric standards, are categorized as suffering from mild to moderate malnutrition. It is questioned whether greater growth is essentially better. As to the future, in Western and in urban developing populations, attempts to control greater attainment of weight for height in schoolchildren, as well as adults, are unlikely to be rewarding, due to unpopularity of a 'prudent' diet on the one hand, and the still diminishing physical activity on the other. Notwithstanding, educational and other efforts to improve the composition of diets and encourage greater physical activity must be energetically pursued.

Growth in renal failure: a longitudinal study of emotional and behavioural changes during trials of growth hormone treatment

Growth and psychological functioning were studied in 30 patients with renal failure over a two year period following the offer of growth hormone treatment for significant short stature. Parents' concerns about growth decreased significantly during the study. Twenty eight parents (93%) accepted growth hormone treatment; most (74%) were satisfied with it and would opt for it again (89%). The views of these parents were unrelated to growth outcome in their child. This suggests that the positive responses were related more to the effort to improve growth than to any objective treatment success. In contrast children's reduction in concern about growth, satisfaction with treatment (36%), and decision to opt for growth hormone again (50%) were all significantly related to improvement in growth. Parents' reports of non-compliance increased significantly from 41% at 1 year to 91% at 2 years in the group as a whole. No significant changes were identified in maternal mental distress and no additional costs to the psychological health of the children seem to have resulted from the introduction of growth hormone treatment. A group of children was identified who accepted treatment but had continued poor growth. These appeared to be at particular risk of both physical problems and associated or consequent psychological difficulties.