R Hauspie

References for growth and pubertal development from birth to 21 years in Flanders, Belgium

Background: Due to the secular trend in length and height, growth references need to be updated regularly. Reference charts that were until recently used in Belgium are based on samples collected more than 30 years ago, and references for body mass index (BMI) and pubertal development have not been established before. Aims: To establish contemporary cross-sectional reference charts for height, weight, BMI, head circumference, and pubertal development from birth to 21 years of age, based on a representative sample of children from Flanders, Belgium. Subjects and methods: 15 989 healthy subjects of Belgian origin, 0–25 years of age, were measured in 2002–2004. Growth curves were fitted with the LMS method, and percentiles for the pubertal development were estimated with generalized additive models on status quo data from 8690 subjects aged 6–22 years of age. Results: A positive secular trend in height and weight is observed in children above 5 years of age. Adult median height has increased by 1.2 cm/decade in boys and 0.8 cm/decade in girls; median weight by 0.9 kg/decade in boys, and 1.0 kg/decade in girls, and the weight distribution became more skewed. The BMI curve is comparable to that of other populations, except for higher percentiles. This reflects the increasing prevalence of overweight and obesity. Median age at menarche (13.0 years) has not advanced any more over the past 50 years. Median ages at menarche and B2 in girls and G2 or T4 in boys are comparable to other West European estimates, but approximately 10% enter G2/T4 before 9 years of age. Conclusions: The ongoing secular trend in height and weight makes growth charts previously used in Belgium obsolete. New representative charts for growth and pubertal development are introduced. For weight monitoring, it is advised that the now-available BMI growth charts are used.

Overweight and obesity in Norwegian children: prevalence and socio-demographic risk factors

Aim:  The aim of this study was to estimate the prevalence of childhood overweight and obesity and to identify socio‐demographic risk factors in Norwegian children.

EEG sleep patterns in man: a twin study

All-night EEG sleep recording was performed for 3 consecutive nights in 26 pairs of normal male twins (14 monozygotic and 12 dizygotic) in order to investigate genetic components of sleep. The analysis was based on average values of repeated sleep measures and controlled for the effect of cohabitation. Our results indicate that a significant proportion of variance in stages 2, 4 and delta sleep as well as in REM density is genetically determined in man. Genetic influences on stage 1 and REM are strongly confounded by a synchronizing effect of the cohabitational status.

Overweight and obesity in Norwegian children: Secular trends in weight‐for‐height and skinfolds

Aim: The prevalence of overweight and obesity in paediatric populations has been rapidly increasing in many countries over the past decades. The aims of the present study were to provide new data on weight‐for‐height and skinfolds, and to compare these to growth references for children between 3 and 17 years, collected in the same city between 1971 and 1974.

Genetic determinants of EEG sleep: a study in twins living apart.

In order to investigate the genetic components of sleep and, in particular, of REM sleep, we performed 3 consecutive all-night EEG recordings in 26 pairs of normal male twins living apart (11 monozygotic and 15 dizygotic). Our results indicate that in man non-genetic rather than genetic influences substantially determine variance in stage REM, in contrast to stages 2, 4 and to delta sleep. In this sample of male twins, waking measures also showed a significant genetic component.

Growth references for 0–19 year-old Norwegian children for length/height, weight, body mass index and head circumference

Background: Previous growth references for Norwegian children were based on measurements from the 1970s and 1980s. New reference data, collected through the Bergen Growth Study and the Medical Birth Registry of Norway, are presented as LMS values. Materials and methods: A cross-sectional sample of children aged 0–19 years in stratified randomized design measured in 2003–2006 as a part of the Bergen Growth Study (n = 7291) and birth data of children born in 1999–2003 from the Medical Birth Registry of Norway (n = 12 576) was used to estimate the new references by the means of the LMS method. Measurement reliability was assessed by test-rest studies. Results: New references were constructed for length/height, weight, body mass index (BMI) and head circumference. Length/height and weight for children aged 0–4 years were similar to previous Norwegian references, but mean height increased up to a maximum of 3.4 cm in boys and 2.5 cm in girls during the pubertal years. Mean height was similar to (or slightly higher) in comparison with other recent European references. Reliability of the measurements compared well with published estimates. Conclusion: Because of the observed secular trends in growth, it is advised to use the new references, which have been endorsed by the Norwegian Department of Health.

Breastfeeding, growth and growth standards: Performance of the WHO growth standards for monitoring growth of Belgian children.

Abstract Background: In 2006, the World Health Organization published universal growth standards for all children from birth to 5 years of age, based on a sample of breastfed children. Aims: The present study documented breastfeeding prevalence in the Flemish Growth Survey 2004, and compared growth of exclusively breastfed children in Flanders with local reference charts and WHO growth standards. Subjects and methods: A subset of 3287 children 0–3 years of age from the Flemish reference population was studied. Prevalence and duration of breastfeeding were estimated with the status quo method. SD scores (SDS) of length/height, weight, BMI, and head circumference were plotted by age. Results: Breastfeeding is initiated for 68.2% of children, and approximately 25% were exclusively breastfed until at least 6 months of age. Breastfed children grow according to a typical pattern that deviates from the local reference curve. The average length of breastfed children is reasonably close to the WHO growth standard, but this does not hold for weight, BMI, or head circumference. In Flanders, breastfed children are more comparable to the local reference than to the WHO growth standards. Conclusions: Growth of breastfed children is similar to the WHO standards for length, but not for other traits. In Flanders, the use of the recent local growth reference is advised for both breastfed and formula-fed children.

The use of local reference growth charts for clinical use or a universal standard: A balanced appraisal

224 A much-debated topic is whether a growth chart should be local, national or international. On the one hand, if we consider that, by definition, a reference chart describes the anthropometry of a given population, we can conclude that we need as many reference charts as the number of different populations, no matter whether their anthropometric differences are ascribable to ethnic characteristics or to environmental, nutritional, socioeconomic, and health conditions. On the other hand, if we believe that all healthy children under unrestricted conditions fully express their growth potential, and that growth potential varies between individuals but not between populations, then a unique standard should apply to all children.

Total Pubertal Growth and Markers of Puberty Onset in Adolescents with GHD: Comparison between Mathematical Growth Analysis and Pubertal Staging Methods

Two methods of determining puberty onset (Preece- Baines model 1 (PB1) and Tanner staging) were used to calculate total pubertal growth (TPG) in adolescents with growth hormone deficiency (GHD). Patients and Methods: 34 patients (11 girls) met the following inclusion criteria: isolated GHD, >2 years growth hormone therapy prior to puberty onset, regular weight-adjusted GH dosage, known final height (age >21 years or height velocity <0.5 cm/year), no induction of puberty. PB1 was used to define age and height at onset of the pubertal growth spurt (‘take-off’). Results: The results (mean ± SD) were as follows: in girls, mean age at take-off was 9.8 years; 2.0 ± 1.1 years before breast stage B2. In boys, mean age at take-off was 11.3 years; 1.4 ± 0.8 years before testes volume >3 ml. Height at take-off was lower than at Tanner stage 2 by 12.4 ± 7.6 cm in girls and 7.7 ± 5.3 cm in boys. TPG was thus markedly greater (p < 0.001) using the PB1 method, as compared with Tanner stage2. Peak height velocity was normal. Final height was –0.5 ± 0.7 SDS in females and –0.4 ± 0.9 SDS in males. Conclusions: The method of measuring TPG from take-off is more objective, and has potentially greater implications for GH therapeutics than the Tanner stage method. In our study, 40% of TPG occurred before ‘breast stage B2’ was attained in GHD girls; whereas 23% of TPG occurred before ‘testes >3 ml’ in GHD boys.

Growth of children living in the outskirts of Ankara: Impact of low socio-economic status

Background: Most studies of the growth of Turkish schoolchildren are limited to large cities and to subjects from high socio-economic background. Very little is known about growth and development of rural, suburban and low socio-economic children in Turkey. Aim: The purpose of this study is to compare height and weight of school-aged children of low socio-economic background with available growth data from high socio-economic strata, and to verify the possible influences of three socio-demographic parameters on their growth. Subjects and methods: The sample consisted of 1052 girls and 1223 boys, aged between 7–17 years, living in the outskirts of Ankara, a suburban area of poor socio-economic background. Centile distributions for height and weight were estimated by the LMS-method. ANOVA and Students t-test were used to compare mean z-scores for height and weight among the various categories of the socio-demographic parameters. Results: Children living in the outskirts of Ankara have lower mean values for height and weight when compared with growth data of upper socio-economic strata children. The differences were most pronounced during adolescence. Skinfolds were higher in girls than in boys at all ages (largest p ≤ 0.007). There was no clear relationship between growth and the number of siblings, the number of rooms in the house, the mothers and fathers education, and the fathers professional status (p>0.05), except for the height of girls (p < 0.05). Conclusion: It is suggested that the lower growth status of children living in the outskirts of Ankara is attributable to the poor socio-economic status of this suburban population, which has not changed over the past decades. It is postulated that the growth impairment during adolescence might be due to a reduced tempo of growth in these children. Résumé. Arrière plan: En Turquie, la plupart des études de croissance ont été limitées à des échantillons de grandes villes et de haut niveau socio-économique. On sait peu de choses sur les modalités de la croissance et du développement des enfants ruraux, périurbains et de niveau socio-économique modeste. But: Cette étude compare les statures et les poids d’enfants turcs de milieu socioéconomique modeste avec les données des strates socioéconomiques favorisées et analyse les influences éventuelles de trois facteurs sociodémographiques sur leur croissance. Sujets et méthodes: L’échantillon est formé de 1052 filles et de 1223 garçons âgés de 7 à 17 ans, vivant dans une zone périurbaine défavorisée de la banlieue d’Ankara. Les distributions de centiles pour la stature et pour le poids, ont été estimées par la méthode des moindres carrés et l’analyse de la variance et le test de Student ont été utilisés afin de comparer les z-scores moyens de la stature et du poids en fonction de diverses catégories de paramètres sociodémographiques. Résultats: Les enfants de la banlieue d’Ankara ont des valeurs moyennes de stature et de poids plus basses que celles des enfants de milieu favorisés, les différences étant plus prononcées lors de l’adolescence. Les plis cutanés sont plus épais chez les filles que chez les garçons quelque soit l’âge (p ≤ 0,007). Il n’y a pas d’association nette entre la croissance et le nombre de frères et sœurs, le nombre de pièces du foyer, l’éducation de la mère et du père et le statut professionnel du père (p>0,05), à l’exception de la stature des filles (p<0,05). Conclusion: Il est vraisemblable que les modalités de croissance moins favorables qu’on observe chez les enfants de la banlieue d’Ankara, soient dues à leur mauvais statut socioéconomique qui n’a pas changé au cours des récentes décennies. On postule que leur déficit de croissance au cours de l’adolescence peut être le fait d’un tempo de croissance réduit. Zusammenfassung. Hintergrund: Die meisten Wachstumsstudien an Türkischen Schulkindern sind auf große Städte und Probanden mit hohem sozioökonomischen Hintergrund beschränkt. In der Türkei ist sehr wenig über Wachstum und Entwicklung von Kindern aus ländlichen Regionen und Vorstädten und Kindern aus niedrigen sozioökonomischen Schichten bekannt. Ziel: Sinn dieser Studie ist es, Körperhöhe und Gewicht von Kindern mit niedrigem sozioökonomischen Hintergrund im Schulalter mit verfügbaren Wachstumsdaten aus hohen sozioökonomischen Schichten zu vergleichen und mögliche Einflüsse von drei soziodemographischen Parametern auf ihr Wachstum nachzuweisen. Probanden und Methoden: Die Stichprobe bestand aus 1052 Mädchen und 1223 Knaben im Alter zwischen 7 und 17 Jahren, die in den Vorstädten von Ankara wohnen, einem suburbanen Bezirk mit sozioökonomisch ärmlichem Hintergrund. Perzentilverteilungen für Körperhöhe und Gewicht wurden nach der LMS-Methode geschätzt. ANOVA und Students t-Test wurden verwendet, um mittlere Z-Werte für Körperhöhe und Gewicht zwischen den verschiedenen Kategorien der soziodemographischen Parameter zu vergleichen. Ergebnisse: Kinder, die in den Vorstädten von Ankara leben, haben, im Vergleich mit Wachstumsdaten aus der oberen sozioökonomischen Schicht, niedrigere Mittelwerte für Körperhöhe und Gewicht. Die Unterschiede waren während der Adoleszenz am stärksten ausgeprägt. In allen Altersgruppen waren Hautfettfalten bei Mädchen dicker als bei Knaben (maximal p<0,007). Es gab keine deutliche Korrelation zwischen Wachstum und Geschwisterzahl, Zimmerzahl im Hause, Bildungsgrad von Müttern und Vätern, und dem beruflichen Status des Vaters (p>0,05), mit Ausnahme der Körperhöhe von Mädchen (p<0,05). Zusammenfassung: Es wird angenommen, dass das geringere Wachstum von Kindern, die in den Vorstädten von Ankara leben, auf den ärmlichen sozioökonomischen Status dieser suburbanen Bevölkerung, der sich in den vergangenen Jahrzehnten nicht geändert hat, zurückzuführen ist. Es wird postuliert, dass der Kleinwuchs in der Adoleszenz die Folge eines verringerten Wachstumstempos dieser Kinder ist. Resumen. Antecedentes: la mayor parte de los estudios de crecimiento de los escolares turcos se limita a las grandes ciudades y a sujetos de nivel socioeconómico alto. Se sabe muy poco sobre el crecimiento y desarrollo de los niños rurales suburbanos de nivel socioeconómico bajo de Turquía. Objetivo: el propósito de este estudio es comparar la estatura y el peso de los escolares de nivel socioeconómico bajo con datos disponibles sobre el crecimiento de los estratos de nivel socioeconómico alto, y verificar las posibles influencias de tres parámetros sociodemográficos sobre su crecimiento. Sujetos y métodos: la muestra la componen 1.052 niñas y 1.223 niños, de 7 a 17 años de edad, residentes en los extrarradios de Ankara, un área suburbana de nivel socioeconómico pobre. Las distribuciones centilares de la estatura y el peso se estimaron mediante el método LMS. Se utilizaron un test ANOVA y la t de Student para comparar las puntuaciones z medias de la estatura y el peso entre las diferentes categorías según los parámetros sociodemográficos. Resultados: los niños que residen en los extrarradios de Ankara tenían menores valores medios de estatura y peso cuando se les comparó con los niños de los estratos socioeconómicos más altos. Las diferencias fueron más marcadas durante la adolescencia. Los pliegues eran mayores en las chicas que en los chicos a todas las edades (la mayor p<0,007). No había una relación clara entre el crecimiento y el tamaño de la fratría, el número de habitaciones de la casa, el nivel educativo de la madre y del padre y la situación profesional del padre (p>0,05), excepto para la estatura de las chicas (p<0,05). Conclusión: se sugiere que el menor nivel de crecimiento de los niños que viven en los extrarradios de Ankara es atribuible al bajo nivel socioeconómico de esta población suburbana, que no ha cambiado durante las últimas décadas. Se postula que las diferencias en el crecimiento durante la adolescencia podrían deberse a una reducción del ritmo de crecimiento en estos niños.