Reference values of inside leg length and inside leg length to stature ratio for Japanese children, 0-12 years of age.

BACKGROUND: Large datasets of detailed anthropometric measurements are scarce in children. The Japanese Standard Association 1978-1981 survey provides a rare opportunity to use high quality data from Japanese children. AIM: To construct inside leg length (ILL) and inside leg length to stature ratio (ILL/S) reference centile curves for Japanese children. SUBJECTS AND METHODS: The study sample consisted of 14,825 boys and 14,577 girls age 0-18 years for stature and weight measurements, and 9064 boys and 8796 girls age 0-12 years for ILL measurements, who participated in the 1978-1981 national survey on body sizes. LMS method was used to construct the reference centile curves. The reference centile curves for stature, weight, ILL, and ILL/S were compared to those of British children. RESULTS: The L, M, and S reference values for Japanese children are presented for stature, weight, ILL, and ILL/S. Compared with British children of 0-12 years of age, Japanese children of 0-12 years of age had shorter median stature, shorter median ILL, and shorter median ILL/S. CONCLUSION: We present the first reference values for ILL and ILL/S in Japanese children. Japanese children had relatively shorter legs compared to British children from infancy.

Population-based waist circumference reference values in Japanese children (0-6 years): comparisons with Dutch, Swedish and Turkish preschool children.

BACKGROUND: During 1978-1981 the Japanese Standards Association conducted a national survey to collect 64 distinct body measurements for Japanese children and adults. During 1978-1981, the prevalence of childhood obesity was relatively low yet the population was well nourished in Japanese children. The aim of this study is to construct waist circumference and waist circumference to stature ratio reference centile curves for Japanese preschool children. METHODS: We utilized 1978-1981 national survey data on body sizes. There are 4937 boys and 4758 girls age 0-6 years for waist circumference measurements. Waist circumference was measured at the level of the umbilicus. Using LMS method, centile curves were constructed for waist circumference and waist circumference to stature ratio. These reference values were compared with those of Dutch, Swedish and Turkish children. RESULTS: Centile reference curves were made for clinical and epidemiological use. Japanese children had smaller waist circumference centile values as compared to waist circumference measured at the midpoint of the lowest rib cage and the iliac crest of Dutch, Swedish and Turkish children. However, Japanese children had comparable waist circumference to stature ratio centile values to those of Dutch and Turkish children. CONCLUSIONS: This study presents the first age-, sex-, and ethnicity-specific reference values for waist circumference and waist circumference to stature ratio in Japanese preschool children.

National anthropometric reference values and growth curves for Japanese children: history and critical review.

Context: Child health statistics are a critical component of child health assessment. However, the importance of nationally representative data on growth is not well recognised for Japanese children. Objective: The aim of this paper is to review the national growth surveys for Japanese children and to discuss the clinical use of the national growth reference values and growth curves. Methods: There are five governmental organisations surveying health and growth in Japanese children. Based on these studies, several aspects of the current governmental policy on child growth assessment have been examined. This review focussed on national anthropometric studies reported by Japanese investigators in English for international readers to understand Japanese issues. Results: A variety of growth reference curves have been developed since the early 1980s in Japan. However, these references have several limitations: incomplete data for both infants and young adults, limited description of socio-economic factors and continued governmental use of weight-for-height rather than BMI. Conclusion: Japanese child health statistics use measures that are applicable only to Japanese children.

Systemic lupus erythematosus in a patient with Noonan syndrome-like disorder with loose anagen hair 1: More than a chance association.

Systemic lupus erythematosus (SLE) has been reported among patients with RASopathy. Five patients have been reported: three with SHOC2 variants, one with a PTPN11 variant, and one with a KRAS variant. SHOC2 variant might represent a relatively common predisposing factor for SLE among the RASopathy genes. However, the clinical details were only reported for two patients, while information on the remaining patient appeared only in a tabular format with minimal clinical description. Here, we report a patient with a SHOC2 variant and SLE. The proband was a 28-year-old male patient with intellectual disabilities, a short stature, dysmorphic facial features, and thin hair. He developed hypertrophic cardiomyopathy and afebrile generalized seizures at the ages of 7 and 18 years, respectively. At the age of 24 years, he presented with a 3-day history of intermittent fever accompanied by right chest pain and a malar butterfly rash. He fulfilled both the American College of Rheumatology (ACR) criteria and the Systemic Lupus International Collaborating Clinics (SLICC) criteria for SLE and was successfully treated with prednisolone. Medical exome sequencing identified a de novo SHOC2 variant (c.4A > G, p.S2G). The present report of a second patient who fulfills both the ACR criteria and the SLICC criteria of SLE. We suggest that the association between SHOC2 variant and SLE represents more than a chance association. In the event of fever of unknown origin in patients with constitutional SHOC2 pathogenic variant, SLE should be suspected.

WHO 2006 Child Growth Standards overestimate short stature and underestimate overweight in Japanese children.

BACKGROUND: It is unclear whether the World Health Organization (WHO) 2006 Child Growth Standards are applicable to East Asian populations. We investigated the applicability of the WHO standards of length/height and weight to a cohort representing middle-class children in Japan. METHODS: A cohort of children aged 0-5 years (3430 boys, 3025 girls) in the Tokyo Child Care Center Survey consecutively recruited from 2007 to 2013 were studied. Age- and sex-specific z-scores of length/height, weight and weight for length/height were calculated relative to either the WHO standards or the Japanese 2000 Growth References (nationally representative cross sectional survey data). RESULTS: Compared with the WHO standards, Japanese children at birth, 1, 3, 5 years were shorter (length/height standard deviation score [SDS] -0.26, -0.82, -0.81, -0.63 for boys, and -0.15, -0.67, -0.84, -0.62 for girls, respectively) and lighter (weight SDS -0.62, -0.36, -0.34, -0.42 for boys and -0.60, -0.17, -0.29, -0.43 for girls, respectively). Weight for length/height showed smaller differences at various length/height points (SDS -0.05 to 0.15 for boys, 0.01 to 0.29 for girls, respectively). CONCLUSIONS: Adoption of the WHO standards would substantially alter the prevalence of short stature, underweight and overweight in Japanese children 0-5 years of age. These findings advocate the use of the national references in Japan.

Prevalence of central fatness in 1992-1994: 40% of Japanese boys 6-17 years.

Obesity in children is a serious public health problem in Japan. However, the prevalence of central fatness has not been well determined in Japanese youth. We studied the relationship between body mass index (BMI) and waist circumference (WC) using line of equality analysis in 5,787 boys and 4,639 girls aged 6 to 17 years who participated in the 1992-1994 national survey on body sizes. WC was measured at the level of maximum waist narrowing in girls (WC1) and at the level of the top of iliac crest in boys (WC2). Using the 1978-1981 national survey data as baseline reference, excess fatness was defined as measurements exceeding the 90th centile in WC or in BMI. Among boys, 2,466 (42.6%) had WC2 >90th centile and 1,029 (17.8%) BMI >90th centile; whereas among girls, 895 (19.3%) had WC1 >90th centile and 673 (14.5%) BMI >90th centile. WC2-standard deviation scores (SDS) exceeded BMI-SDS in 5,060 (87.4%) boys and WC1-SDS exceeded BMI-SDS in 3,168 (68.3%) girls, respectively. Our results suggested a much higher prevalence of central fatness than generally recognized for Japanese children and adolescents, in particular, in Japanese boys.

Human Chorionic Gonadotropin Stimulation Test in Prepubertal Children with Micropenis Can Accurately Predict Leydig Cell Function in Pubertal or Postpubertal Adolescents.

BACKGROUND/AIM: To evaluate the accuracy of the human chorionic gonadotropin (hCG) stimulation test in children with micropenis in predicting later Leydig cell function. METHODS: We conducted a retrospective investigation of testosterone response to a 3-day hCG test (3,000 IU/m2/day) in prepuberty to indicate the need for hormone replacement therapy (HRT) in adolescence. RESULTS: Fifty Japanese boys (range, 0.8-15.4 years of age; median, 8.9) with micropenis were enrolled. Thirty-four spontaneously developed puberty and preserved the ability of testosterone production (group 1), while 16 did not develop any pubertal signs without HRT (group 2). Serum testosterone levels after the hCG test (post-hCG T) in group 2 (range, <0.05-1.1 ng/ml; median, 0.24) were significantly lower than in group 1 (range, 0.5-8.7 ng/ml; median, 2.4; p < 0.0001). Based on true positives who required continuous HRT, the area under the receiver-operating characteristics curve for post-hCG T was 0.983 [95% confidence interval (CI), 0.90-1.00]. The post-hCG T cut-off level corresponding to the Youden index was 1.1 ng/ml (95% CI, 1.0-1.1), with a sensitivity of 100.0% (95% CI, 79.4-100.0) and a specificity of 94.1% (95% CI, 80.3-99.3). CONCLUSIONS: The hCG test in prepubertal children with micropenis can be useful for predicting Leydig cell function in pubertal or postpubertal adolescents. The post-hCG T cut-off level of 1.1 ng/ml is recommended to screen for those who will likely require HRT for pubertal development.

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

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.

Waist circumference centiles by age and sex for Japanese children based on the 1978-1981 cross-sectional national survey data.

AIM: The aim of this study was to establish reference values for waist circumference among Japanese youths using the 1978-1981 nationally representative data. SUBJECT AND METHODS: Growth charts were derived using Cole's LMS method, which adjusts the waist circumference distribution for skewness and allows waist circumference to be expressed as centile or standard deviation score. The sample population consisted of 19 233 children aged 6-18 years. Waist circumference was measured at the level of maximum waist narrowing in girls and at the level of the top of the iliac crest in boys. RESULTS: Comparison was made between the 1978-1981 and 1992-1994 waist circumference charts, showing a large increase in waist circumference over time; the mean difference was 1.1 and 0.5 SD score units in boys and girls, respectively. Defining cut-offs for central fatness as the 90th and 95th centiles of the 1978-1981 reference, the prevalences in 1992-1994 were, respectively, 42.3% and 25.2% in boys and 19.1% and 10.9% in girls. The corresponding prevalences in 1978-1981 were 10% and 5% by definition. CONCLUSION: This study showed increasing trends in waist circumference, particularly in boys during the period of the two surveys and that the 1978-1981 charts serve as better baseline references for waist circumference among Japanese youth.

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.

Reference standard of penile size and prevalence of buried penis in Japanese newborn male infants.

The present study set forth the reference values for penile size and determined the prevalence of buried penis in Japanese full-term newborns. The stretched penile length was measured and the presence of buried penis was assessed at 1-7 days of age in 547 Japanese full-term newborn infants born between 2008 and 2012 in Tokyo. The stretched penile lengths were compared at 1-12 hours and 1-7 days of age in 63 infants and by two observers in 73 infants to estimate postnatal changes and interobserver variation, respectively. The mean stretched penile length was 3.06 cm (SD, 0.26; 95% confidence interval [CI], 3.04-3.08) and the mean ratio of penile length to body length was 6.24 × 100(-1) (SD, 0.55 × 100(-1)), both of which were significantly smaller than those in Caucasian newborn infants. Buried penis was identified in 20 of 547 infants (3.7%; 95% CI, 2.1-5.2%). The first measurements of penile length at 1-12 hours were significantly smaller than the next measurements at 1-7 days (95% CI of the difference, 0.22-0.34). The 95% CI for the limits of agreement in the penile lengths measured by the two observers was -0.58 to -0.40 for the lower limit and 0.33 to 0.51 for the upper limit. These findings indicate that the penile length should be assessed after 24 hours of age by the reference standard of the same ethnicity for identifying micropenis and that buried penis is not uncommon in Japanese full-term newborns.

Trends in thin body stature among Japanese male adolescents, 2003-2012.

BACKGROUND: The desire for thin body stature and unhealthy eating behaviours have spread among Japanese boys. The prevalence of thinness in boys is expected to increase; however, recent trends have not been reported. AIM: To describe changes in the distribution of body mass index (BMI) of Japanese boys, from 2003 to 2012. SUBJECTS AND METHODS: BMI distribution changes were studied in 2599 relatively affluent Japanese children and adolescents, 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 has progressively increased from 2.8-4.7% in 2003-2004 to 5.1-7.6% in 2011-2012 in Japanese boys. Tukey plots showed that the increases in the prevalence of thinness are related to shifts in the entire distribution of BMI in the sample. CONCLUSION: Thin body stature was documented in increasing proportion of Japanese male adolescents. BMI z-scores decreased across the entire BMI centile spectrums, indicating that the whole school population may be at risk of thinness.

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 child's 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 child's 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.

Tracking of BMI in Japanese children from 6 to 18 years of age: Reference values for annual BMI incremental change and proposal for size of increment indicative of risk for obesity.

BACKGROUND: A large incremental increase in BMI indicates excess fat deposition in most children, but the reference values for identifying those at risk for developing obesity have not been defined. AIM: To determine the mean and SD of annual incremental change (ΔSDS) in BMI for Japanese school children. SUBJECTS AND METHODS: A cohort of 669 Japanese children in one private school in Tokyo in whom height and weight were measured annually between 6-17 years of age. Each child's BMI was converted to SDS as based on the 1978-1981 Japanese references for the 12 annual measurements to derive the correlation coefficient, r, between two successive measurements. Using the formula, SD of ΔSDS = √2(1-r), the mean and SD of ΔSDS were obtained. RESULTS: Excess BMI gain was defined in terms of ΔSDS in Japanese children. Annual incremental increase greater than 2 SD of ΔSDS, equivalent to 1-2 BMI units/year for younger children and 2-3 BMI units/year for older children, respectively, indicates rapid increase in body fat in Japanese children. CONCLUSION: Based on analysis of incremental change in BMI in this cohort, a cut-off has been identified that can be used to identify children at risk for developing obesity.

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 > or =95th centile and those with > or = + 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 > or = + 20% excess body weight. CONCLUSION: Official governmental reports significantly underestimate the current epidemic of obesity in Japan.

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

UNLABELLED: 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. CONCLUSIONS: The BMI-SD reference values and charts presented have appropriately reflected the age-dependent skewed distribution of BMI values, and could be a useful tool in growth and nutritional evaluation of Japanese children.

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.

Early initiation of L-dopa therapy enables stable development of executive function in tetrahydrobiopterin (BH4) deficiency.

Executive function (EF) has been presumed to be mediated by the dopaminergic system in the prefrontal cortex. However, little is known about the early development of this function and the roles dopamine plays in it. Tetrahydrobiopterin (BH4) deficiencies are genetic disorders affecting catecholamine and serotonin biosynthesis which, if untreated, result in motor and cognitive symptoms including impairment of EF. A comprehensive neuropsychological test battery was administered to six participants with BH4 deficiency (four males, two females, mean Full-scale intelligence quotient [FIQ] 63.8 [SD 14.7]); all were on replacement therapy with L-dopa and BH4, but time of initiation of treatment varied. Age range (median) was 28 days to 41 years (2y 6mo) at initiation of treatment and 10 to 47 years (19y) at follow-up. On non-EF tests, performance agreed with those of IQ-matched controls (four males, two females; mean age 16y 6mo [SD 6mo]; mean FIQ 62.3 [SD 13.4]). On EF tests those who initiated treatment after 2 years 6 months of age performed poorly. In patients with BH4 deficiency, replacement therapy should be started in the first weeks or months of life. Patients diagnosed before the age of 2 years 6 months obtain normal EF, which suggests dopamine may play a critical role in ensuring stable development of EF in early life.