Growth and Body Mass Index of Brazilians Ages 9 Through 17 Years

Obesity during adolescence is considered a strong predictor of adult obesity, and obesity and overweight have been increasing among Brazilian adults. To gauge the relative frequency of overweight among adolescents in Brazil, we compared the distributions of body mass index (kg/m²) and stature in national population based samples of the U.S. and Brazil. U.S. adolescents were on average about 10 cm taller than Brazilians, although growth spurts occurred at the same age for both populations. Brazilian adolescents were leaner than their U.S. counterparts. This difference was reduced among girls in the postpubertal period. At age 17 years, U.S. boys were about 10 kg heavier than Brazilian boys, but the difference among girls was only 2 kg. In families above the poverty level in the more developed South region, body mass index distribution for boys was closer to that of the U.S., and older girls tended to have higher body mass index than U.S. girls. Within Brazil, body mass index varied by ethnicity with Mulattos, but not Blacks, of both sexes having lower body mass index than Whites of the same age. Urban adolescents had higher body mass index than those living in rural areas. In general, the patterns seen among Brazilian adults were found among children. Among girls, in particular, overweight has become an identifiable problem during adolescence.     

A survey on growth and sexual development of adolescent students in Changhua City: growth of body height and weight

In order to understand the physical growth and sexual development of contemporary adolescents, a cross-sectional survey was conducted during the period September 1983 to May 1984. The population came from all the pupils from 4th grade up, and all the junior and senior high students of Changhua City. By using stratified cluster sampling, 1419 boys and 1599 girls participated, ranging in age from 8 to 19 years. Body weight and height were measured. Growth spurt is a unique event during adolescence. It is well shown in the distance curves and pseudo-velocity curves of body height and weight. In boys, the growth spurt of height spanned from 12.0 to 14.8 years, with peak height velocity (PHV) at 13.5 years. In girls it was from 10.0 to 12.6 years and peaked at 11.5 years. The growth spurt of weight occurred from 12.0 to 15.9 years in boys with peak weight velocity (PWV) at 14.5 years, while girls had a growth spurt at 10.0-12.7 years with PWV at 11.5 years. Girls entered into the growth spurt about 2 years earlier, and also entered into PHV, PWV, two and three years earlier respectively than boys, while boys had a more intense and longer growth during the growth spurt than girls. Between 10.0-13.0 years girls were taller than boys, and between 12.0-13.0 years they were heavier than boys. However, from 13.5 years onward girls were soon surpassed by boys both in height and weight. Growth in height after 16.5 years in boys and after 15.5 in girls was minimal. Growth in weight in boys also became minimal after 16.5 years while girls weight even dropped a little bit after 16.5 years. At the mean age of 17.5 years, boys were 168.1 cm, girls were 156.2 cm in average, boys being 12 cm taller than girls after reaching their final height.     

Do American born Japanese children still grow faster than native Japanese?

Growth patterns of Japanese schoolchildren in Hawaii, composed of 2,954 boys and 3,213 girls aged between 11 and 17, were compared with those comparable groups of Japanese schoolchildren in Japan based on the data published by the Japanese Ministry of Education. Growth characteristics studied were height, weight, and relative weight index, weight/(height). The Hawaii-Japanese boys were taller at early ages but the difference disappeared by age 16. Native Japanese girls were shorter than Hawaii-Japanese until age 13, but they overtook the latter by age 14, exceeding them in height after age 15. A similar pattern was found in weights of girls but the Hawaii-Japanese boys remained consistently heavier by 5.0 to 9.0 kg than native Japanese. The relative weight measure indicated that the Hawaii boys were more "obese" than native Japanese boys for the growth period studied; whereas the same tendency was maintained until age 15 in girls. These observations indicate a marked degree of convergence of the patterns of physical growth of the two populations, whose differences were unmistakably in favor of American born children in earlier studies. It is concluded that the convergence is due largely to the improved environmental conditions in Japan in recent years.     

Estimating height from arm span measurement in Malawian children

Arm span and standing height were measured in 289 boys and 337 girls aged 6-15 years who were free from physical deformities which can affect stature or arm span. The arm span exceeded height in all age groups of boys and in older girls. At the age of 7, 11 and 12 years girls were significantly taller than the boys and had longer arm span while at the age of 15 years, the trend was opposite. The mean difference between the two anthropometric parameters for boys was 5.45 +/- 4.21 cm (t = 3.556, p < 0.001) and for girls was 4.94 +/- 4.96 cm (t = 3.542, p < 0.001). Correlation coefficient between height and arm span measurements for Malawian boys was 0.983 and for girls was 0.986. Height, arm span and height-arm span difference increased with age of children while height to arm span ratio decreased. The gender difference in height-arm span differences was only significant at the age of 15 years. Multiple regression and cross validation were performed. Height of Malawian children of both sexes can be estimated from equation: Height (cm) = 15.756 + (0.168 x age) + (0.839 x arm span) (SEE = 0.760, R2 = 0.988).     

Construction of a New Growth References for China Based on Urban Chinese Children: Comparison with the WHO Growth Standards

Introduction

Growth references for Chinese children should be updated due to the positive secular growth trends and the progress of the smoothing techniques. Human growth differs among the various ethnic groups, so comparison of the China references with the WHO standards helps to understand such differences.

Methods

The China references, including weight, length/height, head circumference, weight-for-length/height and body mass index (BMI) aged 0–18 years, were constructed based on 69,760 urban infants and preschool children under 7 years and 24,542 urban school children aged 6–20 years derived from two cross-sectional national surveys. The Cole’s LMS method is employed for smoothing the growth curves.

Results

The merged data sets resulted in a smooth transition at age 6–7 years and continuity of curves from 0 to 18 years. Varying differences were found on the empirical standard deviation (SD) curves in each indicator at nearly all ages between China and WHO. The most noticeable differences occurred in genders, final height and boundary centiles curves. Chinese boys’ weight is strikingly heavier than that of the WHO at age 6–10 years. The height is taller than that of the WHO for boys below 15 years and for girls below 13, but is significantly lower when boys over 15 years and girls over 13. BMI is generally higher than that of the WHO for boys at age 6–16 years but appreciably lower for girls at 3–18 years.

Conclusions

The differences between China and WHO are mainly caused by the reference populations of different ethnic backgrounds. For practitioners, the choices of the standards/references depend on the population to be assessed and the purpose of the study. The new China references could be applied to facilitate the standardization assessment of growth and nutrition for Chinese children and adolescents in clinical pediatric and public health.     

Sleep Duration and Quality Associated With Obesity Among Arab Children

The link between sleep duration and obesity has been well established in adults, but several epidemiological studies revealed inconsistent findings in adolescents and younger children. This study aimed to investigate the relationship between sleep length and obesity in Saudi students. A total of 5,877 Saudi students, boys (55.2%) and girls (44.8%), aged between 10 and 19 years were randomly selected from elementary, intermediate, and secondary schools in different regions of Riyadh. A questionnaire on sleep behaviors was given. Anthropometry included BMI and waist and hip circumferences. Sleeping ≤7 h significantly increased the risk of obesity in both boys and girls (all age categories) (odds ratio = 1.25–1.38, 95% confidence intervals = 1.02–1.89). Overall prevalence of overweight and obese were higher among those sleeping intermittently (18.68%) than those sleeping continuously (14.5%) (P = 0.024). Short sleep duration and poor sleep quality are significantly associated with obesity among Arab youth. Further studies need to employ more objective measures of sleep, such as actigraphy, and examine the mechanism of these associations.     

Ethnic and secular influences on the size and maturity of seven year old children living in Guatemala City

Three groups of children, those of European parentage, those of Guatemalan parentage, and those of mixed European-Guatemalan parentage were measured for height, weight, and skeletal maturity. The children were born between 1945 and 1965, they were all of high socioeconomic status, and they all attended the same private school in Guatemala City. At 7 years, the boys of the European group were significantly taller than boys of the Guatemalan group. European and mixed European-Guatemalan girls were significantly taller than Guatemalan girls. These results are maturity independent. The influence of skeletal age was removed statistically by analysis of covariance. Girls of the mixed group were significantly heavier than girls of European and Guatemalan groups. Mixed group girls also had more significantly advanced skeletal ages than European girls. When the patterns of size and maturity status are analyzed by sex, there is evidence for a relatively greater environmental influence on the boys and a relatively greater genetic influence on the girls. Dividing the data into two birth year cohorts, 1945 to 1955, and 1956 to 1965, does not provide evidence for secular trends in growth or maturation. These results are similar to those from studies in developed nations that report an end to the secular trend for the “well off” population of those countries.     

Growth and development in school-age children from Rostov region,Russia: Comparison between urban and rural settings

The purposes of the current study were: (1) to describe growth and physical development and establish norms for schoolchildren from Rostov region in Russia; (2) to compare major characteristics of development between urban and rural children by sex and age.Nearly 200,000 children (198,712) aged between 7 and 17 years from 232 urban and rural schools of Rostov region (Southern Federal District of Russia) participated in the study. School age is a period of intensive growth and physiological and psychological development. Irregularities of personal development are caused by a multitude of factors, such as sex differences, heredity, socio-economic status of a family, standard of living, particular environmental conditions, and lifestyle.It has been established that children from the Southern Federal District of Russia had body mass index values higher than age-appropriate norms for all Russians (Total Russian, Rudnev et al., 2014) and World Health Organization charts. Children from urban settings were taller and heavier than children from rural settings.Sex is one of the most influential factors which play key role in determining specific characteristics of growth and personal development. According to our results, boys and girls both had similar age-related changes in weight and height, but their respective dynamics differed. Girls’ height and weight values accelerated at the age 10 to 12 years and plateaued after the age fourteen, whereas in boys height and weight steadily increased with age, showing slight acceleration at the age 12 to 13 years, and reached a plateau by the age of seventeen.     

Comparison of BMI and percentage of body fat of Indian and German children and adolescents

Today, serious health problems as overweight and obesity are not just constricted to the developed world, but also increase in the developing countries (Prentice 2006, Ramachandram et al. 2002). Focusing on this issue, BMI and percentage of body fat were compared in 2094 schoolchildren from two cross-sectional studies from India and Germany investigated in 2008 and 2009. The German children are in all age groups significantly taller, whereas the Indian children show higher values in BMI (e.g. 12 years: Indian: around 22 kg/m2; German: around 19 kg/m2) and in the percentage of body fat (e.g. 12 years: Indian: around 27%; German: around 18-20%) in most of the investigated age groups. The Indian children have significantly higher BMI between 10 and 13 (boys) respectively 14 years (girls). Indian children showed significant higher percentage of body fat between 10 and 15 years (boys) and between 8 and 16 years (girls). The difference in overweight between Indian and German children was strongest at 11 (boys) and 12 (girls) years: 70% of the Indian but 20% of the German children were classified as overweight. In countries such as India that undergo nutritional transition, a rapid increase in obesity and overweight is observed. In contrast to the industrialized countries, the risk of overweight in developing countries is associated with high socioeconomic status. Other reasons of the rapid increase of overweight in the developing countries caused by different environmental or genetic factors are discussed.     

Ethnic Differences in Subcutaneous Adiposity and Waist Girth in Children and Adolescents

The purpose of this study was to examine ethnic differences in adiposity as measured by sum of skinfolds (SKF) and waist circumference (WC) in children and adolescents, after statistical adjustment for the BMI and age. A cross sectional sample of 3,218 (55% white, 49% male) children and adolescents aged 5–18 years who participated in the Bogalusa Heart Study (1992–1994) were included in these analyses. Sex‐specific ANOVAs, adjusted for BMI and age, for each 2‐year age group compared measures of adiposity (SKF and WC) between ethnic groups. No significant differences in the proportions of children and adolescents who were overweight and obese by ethnicity or sex were found. Mean SKF in normal weight (P < 0.0001) and overweight (P < 0.0001) categories was higher for white than black children of both sexes. Across most age categories, white boys and girls had significantly higher SKF than black boys and girls, respectively (P ≤ 0.05). Across most age categories, white boys had significantly higher WC than black boys (P ≤ 0.05) with no difference in the girls, when adjusted for BMI and age. Measures of adiposity in childhood and adolescence were significantly higher in white children compared to black children, when adjusted for BMI and age. Throughout childhood and adolescence, white boys and girls had higher SKF and white boys had higher WC. Differences in adiposity between ethnic groups should be considered in disease risk assessment and stratification as they are observed even for a given BMI level.     

Trend in Height of Turkish and Moroccan Children Living in The Netherlands

ObjectivesTo study trends in height of Turkish and Moroccan immigrant children living in The Netherlands, to investigate the association between height and background characteristics in these children, and to calculate height-for-age-references data for these groups.DesignNationwide cross-sectional data collection from children aged 0 to 18 years by trained professionals in 1997 and 2009. The study population consisted of 2,822 Turkish 2,779 Moroccan, and 13,705 Dutch origin children in 1997and 2,548 Turkish, 2,594 Moroccan, and 11,255 Dutch origin children in 2009. Main outcome measures: Mean height in cm, and mean height standard deviation scores.ResultsIn 2009, mean height at the age of 18y was similar for Turkish and Moroccan children: 177 cm for boys and 163 cm for girls, which was 2 to 3 cm taller than in 1997. Still, Turkish and Moroccan adolescents were 5.5 cm (boys) to 7 cm (girls) shorter than their Dutch peers. No significant differences were found in mean height standard deviation scores across the educational level of the parents, geographical region, primary language spoken at home, and immigrant generation.ConclusionsWhile the secular height increase in Dutch children came to a halt, the trend in Turkish and Moroccan children living in The Netherlands continued. However, large differences in height between Turkish and Moroccan children and Dutch children remain. We found no association with the background characteristics. We recommend the use of the new growth charts for children of Turkish and Moroccan origin who have a height-for-age below -2SD on the growth chart for Dutch children.     

Self-Assessment of Sexual Maturation in Children and Adolescents with Diabetes Mellitus

ObjectiveTo evaluate the reliability of a self-assessment tool as a surrogate means for estimating phase of sexual maturation in children and adolescents with diabetes mellitus.MethodsChildren and adolescents between 8 and 16 years of age with the diagnosis of type 1 or type 2 diabetes mellitus were recruited from the pediatric endocrinology clinic at a children’s hospital. Participants were given a series of gender-appropriate drawings representing the 5 Tanner stages of sexual maturation for genital development in boys and breast and genital development in girls and asked to select the illustration that best represented their current maturity stage. The self-assessments were compared with physical examination findings by pediatric endocrinologists. Demographic and clinical data including age, race, hemoglobin A_1c level, type of diabetes, and body mass index were also collected. Agreement rates between participants and physician assessment were compared. A level of agreement greater than 80% and a k coefficient greater than 0.61 were considered substantial.ResultsEighty-seven children and adolescents completed the study. Agreement rates for girls were greater than 80%. Agreement rates for boys were 76%. All k coefficients for boys and girls were greater than 0.61, corresponding to good agreement. However, peripubertal participants overestimated their sexual maturity rating almost half the time. The role of age, metabolic control (as measured by hemoglobin A_1c), race, type of diabetes, and body mass index did not influence a participant’s ability to accurately assess sexual maturity.ConclusionWhile useful in mid- to late-pubertal youth with diabetes, this self-assessment tool does not appear to be helpful in identifying the early stages of puberty. (Endocr Pract. 2008;14:840-845)     

Mode of Infant Feeding and Achieved Growth in Adolescence: Early Feeding Patterns in Relation to Growth and Body Composition in Adolescence

TULLDAHL, JENNY, KJELL PETTERSSON, SUSAN W. ANDERSSON, AND LENA HULTHÉN. Mode of infant feeding and achieved growth in adolescence: Early feeding patterns in relation to growth and body composition in adolescence. Obes Res. Objective: Feeding mode in infancy and differences in childhood growth have been studied in several longitudinal studies, but few studies have followed children up to adolescent age. There is evidence that formula-fed infants weigh more and are taller than their breast-fed counterparts, and indications that this difference may sustain. Research Methods and Procedures: We have studied the relations between length of breast-feeding, growth, and body composition in a group of 781 representatively chosen adolescents. Data on feeding pattern in infancy and on weight and height from birth up to 18 years were collected. We studied the relation between high body mass index (BMI) (defined as ≤85^th percentile) in adolescence and length of breast-feeding. Results: Girls who were not breast-fed or breast-fed for less than 3 months had a significantly higher height curve than girls exclusively breast-fed for more then 3 months. There were tendencies towards higher values of adipose tissue measured by skinfolds in girls breast-fed for 3 months or less. Short duration of exclusive breast-feeding was associated with higher BMI (p<0. 04). In a subgroup of 194 adolescents, body composition was measured with dual energy X-ray. Both boys and girls who were exclusively breast-fed for more than 3 months were leaner and showed a trend towards lower skinfold values. Conclusion: These results are important to include in the debate about optimal feeding in infancy. Regarding breastfeeding as a standard, our results imply that formula fed infants may be at risk for overfeeding, which might lead to overweight, even up to adolescent age.     

Pediatric Continuous Reference Intervals of Serum Insulin-like Growth Factor 1 Levels in a Healthy Chinese Children Population – Based on PRINCE Study

ObjectivesWe aimed to establish age- and sex-dependent reference intervals for insulin-like growth factor 1 (IGF-1) based on the measurements of healthy Chinese children from the pediatric reference intervals in China study and to investigate whether body mass index (BMI) and height affect IGF-1 levels.MethodsA total of 3753 individuals with eligible blood specimens resampled from the pediatric reference intervals in China population were enrolled as reference individuals. IGF-1 levels were measured using a chemiluminescent immunoassay kit. The lower limit and upper limit values of the reference individuals were calculated by defining the 2.5th and 97.5th percentiles. The skewness-median-coefficient of variation method was used to calculate the standard deviation score (SDS) of serum IGF-1, and cubic spline curves were applied to depict a smoothed curve for each age- and sex-specific stratification of the L, M, and S parameters.ResultsSerum IGF-1 levels increased with age from the age of 1 year, peaking at around the age of 13 years in girls and 15 years in boys and then began to decline (both P <.001). Before 14 years, IGF-1 levels were higher in girls than in boys at the same age, and the difference was statistically significant (P < .05), but there was no significant difference in the IGF-1 levels between girls and boys aged 14 to 16 and 18 years. The Spearman correlation coefficients of height SDS, weight SDS, and BMI SDS with IGF-1 SDS were 0.29, 0.33, and 0.20, respectively (P < .001).ConclusionThis study established age- and sex-specific normative IGF-1 data for Chinese children and adolescents between the ages of 1 and 19 years. The BMI and height SDS had no effect on IGF-1 levels in healthy children.     

Reference values for height, weight and body mass index of German born Turkish children

Turkish children and adolescents born in Northern Europe grow different from native Northern European children, but reference values for height, weight and BMI for these children do not exist. With this study, we intend to provide growth standards for German born Turkish children. Data were obtained from 797 Turkish children and adolescents born in Germany age 0-25.8 years (males), respectively 0-18.3 years (females). We generated synthetic reference values for height, weight, and BMI. The results show that Turkish children and adolescents are heavier after the age of 6 years, and that they remain short after puberty. Eighteen year old Turkish men, and 15-year-old Turkish women are shorter (males 175.2 cm vs. 180.4 cm, p < 0.05; females 159.3 cm vs. 165.0 cm, p < 0.05), and heavier than Germans. Six out of 53 young Turkish men and 9 out of 100 young Turkish women were obese. Twelve out of 53 young Turkish men (23%) and 18 out of 100 young Turkish women (18%) have fallen below the 3rd centile for height. It can be concluded that growth of Turkish children and adolescents born in Germany significantly differs from native children. Reference LMS values for body height, weight and BMI of German born Turkish boys and girls are presented.     

Sex Differences in Cardiovascular Disease Risk in Adolescents With Type 1 Diabetes

BackgroundCardiovascular disease is seen at a younger age and at a higher prevalence in patients with type 1 diabetes than in the general population. It is well described that women with type 1 diabetes have a higher relative risk of cardiovascular disease than men with type 1 diabetes, unlike that seen in the general population. The pathophysiology behind this is unknown.ObjectiveWe performed a cross-sectional study to examine sex differences in cardiovascular disease risk factors in adolescents with type 1 diabetes between ages 13 and 20 years, compared with children of a similar age without type 1 diabetes.MethodsAll patients underwent a dual energy x-ray absorptiometry scan to measure body composition and a pulse wave test measure of arterial elasticity. Fasting serum lipid levels, apolipoprotein B, and apolipoprotein C-III levels were measured in each patient. Twenty-nine children with type 1 diabetes (10 girls, 19 boys) and 37 healthy children (18 girls, 19 boys) participated.ResultsAlthough no sex differences for body mass index (P = 0.91) and glycosylated hemoglobin (P = 0.69) were seen, girls with type 1 diabetes had a significantly higher percent trunk fat compared with boys (P = 0.004). No sex differences were found (P > 0.05) for percent trunk fat in adolescents without diabetes. There was no sex difference among any other cardiovascular risk factors in either children with or without diabetes.ConclusionsFemale adolescents with type 1 diabetes have more centrally distributed fat, which may contribute to their relatively higher cardiovascular disease risk. Attenuation of the central distribution of fat through exercise and dietary modifications may help ameliorate their subsequent cardiovascular disease burden.     

Significant sex difference in the association between C‐reactive protein concentration and anthropometry among 13‐ to 19‐year olds,but not 6‐ to 12‐year olds in Nepal

Life history theory predicts a trade‐off between immunostimulation and growth. Using a cross‐sectional study design, this study aims to test the hypothesis that C‐reactive protein (CRP) is negatively associated with height‐for‐age z‐scores (HAZ scores) and BMI‐for‐age z‐scores (BAZ scores) among 6‐ to 19‐year olds (N = 426) residing in five Nepalese communities. Dried blood spot (DBS) samples were collected and assayed for CRP using an in‐house enzyme immunoassay (EIA). Sex‐ and age‐group‐specific CRP quartiles were used to examine its association with growth in linear mixed‐effects (LME) models. A significant difference was found in the proportion of elevated CRP (>2 mg/L, equivalent to ～3.2 mg/L serum CRP) between 13‐ and 19‐year‐old boys (12%) and girls (4%). Concentrations of CRP were positively associated with HAZ score among adolescent (13–19 years) boys, which may indicate that individuals with greater energy resources have better growth and a better response to infections, thus eliminating the expected trade‐off between body maintenance (immunostimulation) and growth. Adolescent boys with low BAZ and HAZ scores had low CRP values, suggesting that those who do not have enough energy for growth cannot increase their CRP level even when infected with pathogens. Among adolescent girls a positive association was observed between CRP and BAZ scores suggesting the possible effects of chronic low‐grade inflammation due to body fat rather than infection. The association between CRP and growth was less evident among children (6–12 years) compared with adolescents, indicating that the elevated energy requirement needed for the adolescent growth spurt and puberty may play some role. Am J Phys Anthropol 154:42–51, 2014. © 2014 Wiley Periodicals, Inc.     

Extreme levels of underweight and stunting among pre-adolescent children of low socioeconomic class from Madhyamgram and Barasat, West Bengal, India

A cross-sectional study on 1206 children (788 boys, 618 girls) aged 1-12 years, belonging to low socioeconomic status, of Barasat and Madhyamgram, West Bengal, India, was undertaken to investigate age and sex variations in height and weight. It also evaluated the levels of underweight and stunting among them. Anthropometric measurements included weight and height. Weight-for-age (WA) and height-for-age (HA) <-2 z-scores were used to evaluate underweight (UW) and stunting (ST), respectively, following the National Center for Health Statistics (NCHS) Guidelines. Results showed that boys aged 4 and 11 years were significantly heavier than girls of corresponding ages. Boys aged 7 years were significantly taller than girls of the same age. Significant (p < 0.001) age differences existed in mean weight and height in boys (weight: F = 336.762; height: F = 565.160) as well as girls (weight: F = 275.320; height = 498.715). Results also revealed that the mean z-scores of WA (WAZ) and HA (HAZ) were less than (negative values) those of NCHS for both sexes at all ages. The overall (age combined) rate of UW was 60.4% and 51.3%; while that of ST was 51.7% and 48.4%, in boys and girls, respectively. Based on World Health Organization classification of severity of malnutrition, the prevalence of UW and ST were very high (> or = 30%) in both sexes. In conclusion, this study demonstrated that the prevalence of UW and ST were very high among the subjects. Since the nutritional status of the subjects is not satisfactory, there is need for immediate supplementary nutrition.     

Practice Variation in the Management of Girls and Boys with Delayed Puberty

Objective: Delayed puberty is a common condition, and typical management includes “watchful waiting” and/or sex-steroid therapy. We sought to characterize treatment practices and to assess provider comfort with the management of delayed puberty in girls and boys.Methods: A national survey of pediatric endocrine providers assessed definitions of delayed puberty, practices around sex-steroid therapy, reasons for treatment, and comfort in managing delayed puberty in girls and boys.Results: Of 184 respondents (12% participation rate), 64% and 71% used the traditional age cutoffs for defining delayed puberty of 13 years for girls and 14 years for boys, respectively. Nearly half (45%) of providers would treat boys relatively earlier than girls, compared to 18% who would treat girls relatively earlier (P<.0001). Providers were more likely to cite bone density as a reason to treat girls and alleviating patient and parental distress, accelerating growth, and “jump starting” puberty as reasons to treat boys. Greater experience in endocrine practice was associated with greater comfort managing delayed puberty in both boys and girls. Approximately 80% of providers agreed that clinical guidelines are needed for the management of delayed puberty.Conclusion: There is a high degree of variability in the clinical management of delayed puberty, and our results suggest that providers are more hesitant to treat girls compared to boys and have different reasons for treating each. It remains to be determined if these discrepancies in treatment are justified by biologic differences between girls and boys or represent nonevidence-based disparities in care.Abbreviation: U.S. = United States     

The Influence of Hand Preference on Grip Strength in Children and Adolescents; A Cross-Sectional Study of 2284 Children and Adolescents

Introduction

In adults the preferred hand is often considered to be around 10% stronger than the non-preferred hand. Whether the same is true for children and adolescents remains unclear. The objective of this study is therefore to determine whether there is a difference in grip strength between the preferred and non-preferred hand in developing children, to establish whether this difference is similar for children of a different gender or hand preference, and whether there is a difference in grip strength of the preferred hand of left-preferent (LP) and right-preferent (RP) children.

Design

Cross-sectional study.

Participants

Participants were recruited from schools in the northern provinces of the Netherlands. The study included healthy children and adolescents in the age range of 4–17 years.

Outcome Measures

Each child was allowed a total of four attempts using the JAMAR hand dynamometer, two attempts with each hand. All individual attempts were scored. Hand preference was determined by asking which hand was used to write, or in the case of 4- and 5-year-olds, which hand was used to draw a shape.

Results

The study population comprised 2284 children and adolescents. RP boys and girls scored significantly higher with their preferred hand, the difference amounting to 9.5 and 10.1% respectively. LP girls scored significantly higher with their preferred hand, but this difference was only 3.0%. For LP boys no significant difference was found in favor of either hand. LP children score higher with the non-preferred hand and tie scores on both hands more often than RP children.

Conclusion

The 10% rule of hand preference is applicable to RP children ranging in age between 4 and 17 years, but not to LP children. In contrast to LP boys, LP girls are generally significantly stronger with their preferred hand.