Mikako Inokuchi

Standardized centile curves of body mass index for Japanese children and adolescents based on the 1978–1981 national survey data

Background: The prevalence of overweight among Japanese children and adolescents has steadily increased during the last 20 years. Thus, we utilized the 1978–1981 data collected by the Japanese Ministry of International Trade and Industry to construct reference curves of body mass index (BMI) for contemporary Japanese children and adolescents. Methods: BMI reference values were derived using the LMS method as based on height and weight data from the cross-sectional national survey of Japanese children and adolescents conducted in 1978–1981 (14 012 boys and 13 781 girls, aged 1.5–18.5 years). Results: The Japanese BMI reference curves were constructed for clinical use. The centile values at the upper end of the spectrum apparently differed in British, Dutch, Japanese, and US children and adolescents. In contrast, the centile values at the lower end of the spectrum nearly overlapped with each other in the four populations. Conclusions: Overweight is concentrated in a subgroup of children and does not occur across the entire population of British, Dutch, Japanese, and US children, indicating a subgroup of genetically and/or environmentally more susceptible children in each country. Résumé. Arrière plan: La prévalence du surpoids chez les enfants et adolescents japonais, s’est régulièrement accrue au cours des vingt dernières années. C’est pourquoi nous avons utilisé les données recueillies par le Ministère du Commerce International et de l’Industrie entre 1978 et 1981, afin de construire ds courbes de référence de l’indice de masse corporelle (IMC) des enfants et adolescens japonais contemporains. Méthodes: Les valeurs d’IMC de référence ont été obtenues par la méthode des moindres carrés à partir de données transversales de poids et de stature récoltées entre 1978 et 1981 sur 14012 garçons et 13781 filles âgés de 1,5 à 18,5 ans. Résultats: Les courbes de référence de l’IMC des japonais ont été construites en vue d’un usage clinique. Les valeurs les plus élevées des centiles diffèrent apparemment de celles des enfants et adolescents britanniques, néerlandais et des Etats–Unis. Au contraire, les valeurs de centiles les plus basses se chevauchent presque dans les quatre populations. Conclusions: Le surpoids est concentré dans un sous groupe d’enfants et ne s’observe pas dans l’ensemble de la population des enfants britanniques, néerlandais, japonais et des Etats–Unis, ce qui signale l’existence d’un sous groupe plus susceptible dans chaque pays, que ce soit génétiquement et/ou pour des causes environnementales. Zusammenfassung. Hintergrund: Die Prävalenz von Übergewicht bei Japanischen Kindern und Jugendlichen ist in den letzten 20 Jahren stetig gestiegen. Aus diesem Grunde verwendeten wir Daten, die in den Jahren 1978--1981 vom Japanischen Ministerium für Internationalen Handel und Industrie (Japanese Ministry of International Trade and Industry) gesammelt worden waren, um BMI-Referenzkurven für heutige Japanische Kinder und Jugendlichen zu konstruieren. Methoden: BMI-Referenzwerte wurden mit LMS-Methode basierend auf Körperhöhen- und Gewichtsdaten der nationalen Querschnittsstudie an Japanischen Kindern und Jugendlichen der Jahre 1978--1981 (14012 Knaben und 13781 Mädchen im Alter von 1,5–18,5 Jahren) entwickelt. Ergebnisse: Die Japanischen BMI-Referenzkurven wurden für den klinischen Gebrauch konstruiert. Die Perzentilwerte aus dem oberen Ende des Spektrums unterschieden sich offensichtlich von Britischen, Niederländischen, Japanischen und US-Amerikanischen Kindern und Jugendlichen. Dagegen überlappten sich die Perzentilen weitgehend am unteren Ende des Wertespektrums mit den denen der anderen vier Populationen. Zusammenfassung: Übergewicht findet sich vorwiegend in einer Untergruppe von Kindern und kommt nicht in der gesamten Population von Britischen, Niederländischen, Japanischen und US-Amerikanischen Kindern vor, was darauf hindeutet, dass es eine Untergruppe von genetisch und/oder umweltbedingt empfindlicheren Kindern in jedem dieser Länder gibt. Resumen. Antecedentes: La prevalencia de sobrepeso entre los niños y adolescentes japoneses ha aumentado de manera continua durante los últimos 20 años. Por ello, se han empleado los datos recogidos entre 1978--1981 por el Ministerio Japonés de Comercio Internacional e Industria, para construir curvas de referencia del índice de masa corporal (IMC) para los niños y adolescentes actuales. Métodos: Los valores de referencia del IMC se obtuvieron mediante el método LMS, utilizando datos de la estatura y peso procedentes de la encuesta nacional transversal de niños y adolescentes japoneses, realizada entre 1978--1981 (14.012 chicos y 13.781 chicas, de entre 1,5 y 18,5 años de edad). Resultados: Las curvas de referencia del IMC de los japoneses se construyeron para uso clínico. Los valores centilares en el extremo superior del espectro diferían aparentemente entre los niños y adolescentes británicos, holandeses, japoneses y estadounidenses. Por el contrario, los valores centilares en el extremo inferior del espectro se solapaban en las cuatro poblaciones. Conclusiones: El sobrepeso se concentra en un subgrupo de niños y no se encuentra en toda la población de niños británicos, holandeses, japoneses y estadounidenses, lo que apunta a la existencia de un subgrupo de niños más susceptible genética y/o ambientalmente en cada país.

BMI z-score is the optimal measure of annual adiposity change in elementary school children.

Background: BMI or BMI% adjusted for age has been identified as the optimal measure of short-term adiposity change in kindergarten children aged 29–68 months. The optimal measure of annual adiposity change in older age children, however, has not been determined. Aim: To identify the optimal measure of annual adiposity change for Japanese children aged 6–12 years. Subjects and methods: A cohort of 669 Japanese children in one private school in Tokyo in whom height and weight were measured annually between 6 and 12 years. Each childs annual variability in adiposity was summarized by the standard deviation (SD) of BMI and BMI% adjusted for age, BMI z-score and BMI centile. The SDs were compared in overweight and non-overweight children and correlated with each childs baseline BMI z-score. Results: The within-child BMI, BMI% and BMI centile SDs were significantly different in overweight and non-overweight children, while the BMI z-score SDs were similar in the two groups. Furthermore, the within-child BMI, BMI% and BMI centile SDs were inversely correlated with baseline BMI z-score, whereas BMI z-score SDs were not, with the exception of measurements for grade 1–2 children. Conclusion: The BMI z-score is the optimal measure of annual adiposity change for elementary school children.

Body mass index reference values (mean and SD) for Japanese children.

The aim of this study was to derive the mean and ±1, 2 and 2.5 SD body mass index (BMI) reference ranges as a supplement to the BMI centile reference values published previously for the same group of Japanese children. It is based on 14 012 boys and 13 781 girls of 1.5–18.5 years of age as studied in 1978–1981. The LMS method was utilized for the study.

Gradual Loss of ACTH Due to a Novel Mutation in LHX4: Comprehensive Mutation Screening in Japanese Patients with Congenital Hypopituitarism

Mutations in transcription factors genes, which are well regulated spatially and temporally in the pituitary gland, result in congenital hypopituitarism (CH) in humans. The prevalence of CH attributable to transcription factor mutations appears to be rare and varies among populations. This study aimed to define the prevalence of CH in terms of nine CH-associated genes among Japanese patients. We enrolled 91 Japanese CH patients for DNA sequencing of POU1F1, PROP1, HESX1, LHX3, LHX4, SOX2, SOX3, OTX2, and GLI2. Additionally, gene copy numbers for POU1F1, PROP1, HESX1, LHX3, and LHX4 were examined by multiplex ligation-dependent probe amplification. The gene regulatory properties of mutant LHX4 proteins were characterized in vitro. We identified two novel heterozygous LHX4 mutations, namely c.249-1G>A, p.V75I, and one common POU1F1 mutation, p.R271W. The patient harboring the c.249-1G>A mutation exhibited isolated growth hormone deficiency at diagnosis and a gradual loss of ACTH, whereas the patient with the p.V75I mutation exhibited multiple pituitary hormone deficiency. In vitro experiments showed that both LHX4 mutations were associated with an impairment of the transactivation capacities of POU1F1 andαGSU, without any dominant-negative effects. The total mutation prevalence in Japanese CH patients was 3.3%. This study is the first to describe, a gradual loss of ACTH in a patient carrying an LHX4 mutation. Careful monitoring of hypothalamic–pituitary -adrenal function is recommended for CH patients with LHX4 mutations.

Influenza Vaccination of Schoolchildren and Influenza Outbreaks in a School

BACKGROUND The objective of this retrospective descriptive study was to determine whether the universal influenza vaccination for schoolchildren was effective in controlling influenza outbreaks in a school. A universal vaccination program for schoolchildren was started in Japan in the 1960s, but the government abandoned the program in 1994 because of lack of evidence that the program was effective in preventing influenza in schoolchildren. METHODS Influenza vaccine coverage rates, total numbers of class cancellation days, and absentee rates were reviewed in a single elementary school during the 24-year period during 1984-2007. RESULTS The mean number of class cancellation days and the mean absentee rate in the compulsory vaccination period (1984-1987; mean vaccine coverage rate, 96.5%) were 1.3 days and 2.5%, respectively, and they increased to 8.3 days and 3.2% during the quasi-compulsory vaccination period (1988-1994; vaccine coverage, 66.4%). In the no-vaccination period (1995-1999; vaccine coverage, 2.4%), they were 20.5 days and 4.3%, respectively, and in the voluntary vaccination period (2000-2007; vaccine coverage, 38.9-78.6%), they were 7.0-9.3 days and 3.8%-3.9%. When minor epidemics were excluded, there was a significant inverse correlation between the vaccine coverage rates and both the number of class cancellation days and absentee rates. CONCLUSIONS The universal influenza vaccination for schoolchildren was effective in reducing the number of class cancellation days and absenteeism in the school.

Official Japanese reports significantly underestimate prevalence of overweight in school children: Inappropriate definition of standard weight and calculation of excess weight

Background: The obesity epidemic in Japan continues to increase. However, the prevalence and trends of obesity have not explicitly been determined in Japanese children. Aim: The study estimated the trend and prevalence of overweight in Japanese school children, 1980–2001. Subjects and methods: The 2001 cross-sectional national survey on 334,939 boys and 335,204 girls, 5–18 years of age was studied, using the 1978–1981 references. Main outcome measures were proportion of children with BMI ≥95th centile and those with ≥ + 20% excess body weight. Results: The prevalence of overweight increased 2.6 times (5.0% to 12.9%) in Japanese boys and 2.5 times (5.0% to 12.5%) in Japanese girls during the last two decades as assessed by using BMI, whereas the Japanese Ministry of Education, Culture, Sports and Science and Technology reported a much smaller increment in prevalence (5.8% to 9.2% in boys, 5.6% to 8.0% in girls, respectively) using the same data but based on a cut-off value of ≥ + 20% excess body weight. Conclusion: Official governmental reports significantly underestimate the current epidemic of obesity in Japan.

Prevalence and trends of underweight and BMI distribution changes in Japanese teenagers based on the 2001 National Survey data.

Background: Excessive thinness has been glamorized among Japanese adolescent girls, and unhealthy dieting to lose weight has become a popular practice among them. The prevalence of underweight in contemporary Japanese girls in comparison with that of boys, however, remains to be studied. Aim: The purpose of this study was to determine the prevalence and trends of underweight in contemporary Japanese teenagers of both sexes using nationally representative cross-sectional data. Subjects and methods: Underweight was defined as BMI < 3rd percentile by age and sex of the 1978–1981 reference population as previously reported. These reference values were compared with BMIs of the contemporary population based on the 2001 Cross-sectional National Survey data of Japanese teenagers (215 972 boys and 216 496 girls). Results: The prevalence of underweight was approximately 2–3% in junior high school students of both sexes, 12.5–14.5 years of age, approximately 3% in senior high school students of both sexes, 15.5–16.5 years of age, and approximately 4% in senior high school students of both sexes, 17.5 years of age. Conclusion: The prevalence of underweight decreased among Japanese teenage students of both sexes during the past decades. Female preponderance in the prevalence of underweight was not confirmed.

A cross-sectional growth reference and chart of stretched penile length for Japanese boys aged 0-7 years.

Background/Aim: Reference values for penile length have not been established for Japanese boys. We aimed to develop percentiles and means (and standard deviations) of stretched penile length (SPL) in Japanese boys. Methods: A cross-sectional study was performed in 1,628 Japanese boys aged <9 years from 2007 through 2014. The LMS method was used to develop a growth reference and chart for SPL in boys aged 0-7 years. Interobserver variation in SPLs was assessed in 32 boys (aged 0-11 years, median 3 years) using the Bland-Altman plot. The correlation between SPL and stature, weight or body mass index (BMI) was analyzed by the Pearson test. Results: SPL increases continuously during the prepubertal period, and most rapidly in the first 4 months of life. No significant fixed or proportional bias was found for interobserver variation (p = 0.5; r = 0.33, p = 0.06). There was no significant correlation between SPL z-score and stature z-score (r = 0.14, p < 0.001), weight z-score (r = 0.09, p < 0.001) or BMI z-score (r = 0.01, p = 0.71). Conclusion: These data serve as an updated growth reference for SPL in Japanese boys aged 0-7 years.

Trends in thin body stature among Japanese female adolescents, 2003–2012

Abstract Background: The past decades have witnessed a steady increase in thin body stature associated with unhealthy dieting among Japanese female adolescents. The most recent trends in thinness, however, have not been reported. Aim: To describe changes in the distribution of body mass index (BMI) of Japanese female adolescents, from 2003–2012. Subjects and methods: This study examined BMI distribution changes in 2541 relatively affluent Japanese girls, aged 12.5–17.5 years, during 2003–2012. The 2003 and 2004 data were combined and compared to the combined 2011 and 2012 data. Tukey mean-difference plots were used to study the direction and magnitude of shifts in BMI distributions. Results: Prevalence of thinness (BMI <5th percentile of the 1978–1981 references) has progressively increased from 2.0–5.7% in 2003–2004 to 3.5–7.8% in 2011–2012 in Japanese girls. The downward shift in BMI was larger in 12.5–14.5 year olds than in 15.5–17.5 year olds and more prominent in the lower BMI spectrum. Conclusion: The trend towards thinness has continued in Japanese girls during the past decade. The distribution of BMI suggests thinner and younger sub-groups of girls are more susceptible to this trend.

A case of multisystem Langerhans cell histiocytosis with primary hypothyroidism followed by type 1 diabetes mellitus

We report a case of a 13‐year‐old female with Langerhans cell histiocytosis (LCH) and primary hypothyroidism followed by type 1 diabetes mellitus (DM), both of which are rare complications. In LCH diagnosis, imaging studies showed an enlargement of the thyroid gland, suggesting the involvement of LCH cells. While the pancreas appeared normal, insulin secretion markedly deteriorated 11 months after cessation of chemotherapy. Even without direct pancreatic involvement, there is a possibility that LCH could induce DM as a part of its long‐term complications. In particular, thyroid involvement may be related to the onset of DM. Pediatr Blood Cancer 2009;53:232–234.