Clinical longitudinal standards for height and height velocity for North American children

Relationship Between Timing of Peak Height Velocity and Pubertal Staging in Boys and Girls

Growth and pubertal development are important health markers. We used the data of a longitudinal growth study on a contemporary sample of US youth to examine the relationship between peak height velocity (PHV) and Tanner staging. We observed a substantial variability in the timing of PHV across Tanner stages, which is an important consideration for clinicians when assessing growth.

Comparing Methods for Identifying Biologically Implausible Values in Height, Weight, and Body Mass Index Among Youth

As more epidemiologic data on childhood obesity become available, researchers are faced with decisions regarding how to determine biologically implausible values (BIVs) in height, weight, and body mass index. The purpose of the current study was 1) to track how often large, epidemiologic studies address BIVs, 2) to review BIV identification methods, and 3) to apply those methods to a large data set of youth to determine the effects on obesity and BIV prevalence estimates. Studies with large samples of anthropometric data (n > 1,000) were reviewed to track whether and how BIVs were defined. Identified methods were then applied to a longitudinal sample of 13,662 students (65% African American, 52% male) in 55 urban, low-income schools that enroll students from kindergarten through eighth grade (ages 5-13 years) in Philadelphia, Pennsylvania, during 2011-2012. Using measured weight and height at baseline and 1-year follow-up, we compared descriptive statistics, weight status prevalence, and BIV prevalence estimates. Eleven different BIV methods were identified. When these methods were applied to a large data set, severe obesity and BIV prevalence ranged from 7.2% to 8.6% and from 0.04% to 1.68%, respectively. Approximately 41% of large epidemiologic studies did not address BIV identification, and existing identification methods varied considerably. Increased standardization of the identification and treatment of BIVs may aid in the comparability of study results and accurate monitoring of obesity trends.

Central Precocious Puberty: Update on Diagnosis and Treatment

Central precocious puberty (CPP) is characterized by the same biochemical and physical features as normally timed puberty but occurs at an abnormally early age. Most cases of CPP are seen in girls, in whom it is usually idiopathic. In contrast, ~50% of boys with CPP have an identifiable cause. The diagnosis of CPP relies on clinical, biochemical, and radiographic features. Untreated, CPP has the potential to result in early epiphyseal fusion and a significant compromise in adult height. Thus, the main goal of therapy is preservation of height potential. The gold-standard treatment for CPP is gonadotropin-releasing hormone (GnRH) analogs (GnRHa). Numerous preparations with a range of delivery systems and durations of action are commercially available. While the outcomes of patients treated for CPP have generally been favorable, more research about the psychological aspects, optimal monitoring, and long-term effects of all forms of GnRHa treatment is needed. Several potential therapeutic alternatives to GnRHa exist and await additional investigation.

Biosocial correlates of age at menarche in a British cohort

BACKGROUND

A large number of biosocial variables have been shown to associate with age at menarche, but the results are inconsistent and differentiate not only between countries but within countries as well.

AIM

This study examined age at menarche in a British national cohort in relation to 21 biosocial and anthropometric variables.

SUBJECTS AND METHODS

The analyses were based on 4483 girls from the British National Child Development Study (NCDS).

RESULTS

The majority of girls reached menarche between 12-14 years of age. Girls from smaller families, those living in the East and South East, South West, West Midlands and Wales regions, in tied housing and uncrowded conditions, not sharing a bedroom, not having free school meals, whose families lived in households without financial problems had started menstruating earlier than their peers from families with lower socioeconomic status. However, when all the significant variables were analysed together significant associations remained only for mother's age at menarche, height and weight at 7 years, family size and tenure.

CONCLUSIONS

The results of this study support the hypotheses that intra-uterine growth and conditions in early life as well as socio-economic background are associated with the timing of menarche and that greater childhood growth and better SES are related to earlier menarche.

Response to long-term growth hormone therapy in patients affected by RASopathies and growth hormone deficiency: Patterns of growth, puberty and final height data

RASopathies are developmental disorders caused by heterozygous germline mutations in genes encoding proteins in the RAS-MAPK signaling pathway. Reduced growth is a common feature. Several studies generated data on growth, final height (FH), and height velocity (HV) after growth hormone (GH) treatment in patients with these disorders, particularly in Noonan syndrome, the most common RASopathy. These studies, however, refer to heterogeneous cohorts in terms of molecular information, GH status, age at start and length of therapy, and GH dosage. This work reports growth data in 88 patients affected by RASopathies with molecularly confirmed diagnosis, together with statistics on body proportions, pubertal pattern, and FH in 33, including 16 treated with GH therapy for proven GH deficiency. Thirty-three patients showed GH deficiency after pharmacological tests, and were GH-treated for an average period of 6.8 ± 4.8 years. Before starting therapy, HV was -2.6 ± 1.3 SDS, and mean basal IGF1 levels were -2.0 ± 1.1 SDS. Long-term GH therapy, starting early during childhood, resulted in a positive height response compared with untreated patients (1.3 SDS in terms of height-gain), normalizing FH for Ranke standards but not for general population and Target Height. Pubertal timing negatively affected pubertal growth spurt and FH, with IGF1 standardized score increased from -2.43 to -0.27 SDS. During GH treatment, no significant change in bone age velocity, body proportions, or cardiovascular function was observed.

Right Anterolateral Thoracotomy in the Repair of Atrial Septal Defect: Effect on Breast Development

BACKGROUND AND AIM

The aim of this study was to assess the cosmetic results and the impact on the breast development of a right anterolateral thoracotomy (RALT) in pre-pubertal children who underwent RALT for correction of atrial septal defects.

METHODS

From December 2002 to July 2010, 25 female patients with a mean age of 8.5 ± 1.3 years underwent repair of atrial septal defects with a right anterolateral thoracotomy. Breast symmetry was described by a clinical index. The degree of scoliosis was measured by clinical examination. The subjective evaluation in breast asymetry, size, and shape was assessed by a survey obtained by the patients.

RESULTS

There was no intraoperative or postoperative complication or late mortality in the thoracotomy approach or in the long-term follow-up (7.5 ± 2.2 years). According to the survey, breast asymmetry and differences between both breast size or shape were found in 15 (60%) and seven (28%) patients, respectively. One patient (4%) complained of a keloid scar. Mild sensitive skin deficit in the mammary area was determined in four patients (16%). According to the objective assessment, breast asymmetry was found 12 patients (48%) with index 1 and 13 patients (52%) with index 2.

CONCLUSION

Although it is safe, the RALT is associated with the potential to effect unilateral breast development.

Growth Velocity of Infants From Birth to 5 Years Born in Maku, Iran

BACKGROUND

Growth velocity standards are essential for proper evaluation of child growth. The goal of this study was to construct weight, height and head circumference growth velocity charts for infants.

METHODS

This study includes 256 infants (124 boys and 132 girls) born in Maku, Northwest of Iran, and monitored from birth until they were 5 years. The weights and heights of the subjects were recorded at birth, one, two, four, six months and 1, 1.5, 2, 3, 4 and 5 years of age, while the head circumferences were measured until they were 1.5 years old. In this study, the LMS method using LMS chart maker software, was utilized to obtain growth velocity centiles.

RESULTS

Growth velocity charts for weight, height and head circumference (5th, 50th, 95th percentiles) were obtained. The velocity growth charts decreased rapidly from birth to 2 years and then remained relatively constant up to 5 years for both sexes. The growth velocity of boys was higher than girls through the first year of age but became equal at 12 months of age and no significant difference was seen up to 5 years.

CONCLUSION

Growth velocity studies are really sparse in Iran. In this study, longitudinal data were used to obtain growth velocity centiles. Furthermore, the weight and height velocities of infants from Shiraz, southern Iran, and U.K were compared.

A modified blood pressure to height ratio improves accuracy for hypertension in childhood

BACKGROUND

The blood pressure to height ratio (BP:HT) has been proposed as a simple method for identifying children with elevated BP. This procedure shows good accuracy for the screening of hypertension in adolescents but less so in younger children. Our aim in this study was to modify the BP:HT ratio and determine if this change would increase accuracy when measuring hypertension during childhood.

METHODS

BP levels of 4,327 children (aged 5-12 years) were retrospectively obtained from medical charts. The modified ratio (BT:eHT13) was calculated as: BP/(HT + 7 × (13 - age in years)). Receiver operating characteristic curves were used to estimate cutoff points and the accuracy of the conventional and modified ratio to detect prehypertension and hypertension.

RESULTS

The prevalences of prehypertension and hypertension were 3.91% and 5.44%, respectively. In general, BP:eHT13 showed higher sensitivity (ranging from 0.95 to 1.00) and specificity (ranging from 0.80 to 0.98) in detecting prehypertension, level I hypertension, and level II hypertension than BP:HT (sensitivity ranging from 0.91 to 1.00; specificity ranging from 0.59 to 0.89).

CONCLUSIONS

The modified BP:eHT13 ratio showed better sensitivity and specificity for the screening of BP abnormalities in children aged 5-12 years.

Relationship of calcaneal and iliac apophyseal ossification to peak height velocity timing in children

BACKGROUND

Ossification of the calcaneal apophysis has never been fully characterized. We examined the ossification sequence of the calcaneus in relation to ossification of the iliac apophysis and the timing of the peak height velocity (PHV).

METHODS

Ninety-four healthy children (forty-nine girls and forty-five boys), from three to eighteen years old, were followed longitudinally through growth with annual serial radiographs and physical examinations. These were done at least annually from ten to fifteen years of age. The PHV was calculated using the height measurements of each child. We measured and compared calcaneal and iliac crest apophyseal ossification using foot and pelvic radiographs made on the same day. We correlated the PHV with the degree of calcaneal and iliac ossification.

RESULTS

Ossification of the calcaneal apophysis occurred in an orderly fashion, with the ossification center first appearing a mean of 4.7 years (95% confidence interval [CI], 5.2 to 4.2 years) before the PHV. The apophysis spread across the plantar surface more quickly than the dorsal surface. The apophysis extended completely over the plantar surface a mean of 0.86 year (95% CI, 1.0 to 0.7 year) before the PHV. Fusion of the apophysis followed complete plantar extension over the next two years and was typically complete a mean of 2.1 years (95% CI, 2.0 to 2.2 years) after the PHV. Fusion began in the middle of the apophysis and proceeded outward. Iliac apophyseal ossification did not appear prior to the PHV in any subject.

CONCLUSIONS

The calcaneal apophysis ossifies in a consistent fashion characterized by six different stages. The calcaneal stages occur during narrow intervals in relation to the PHV, allowing the calcaneal system to be used for assessment of skeletal maturity. The PHV occurs prior to iliac ossification, whereas the calcaneal apophysis has four stages of ossification before and two stages after the PHV.

BMI as a mediator of the relationship between muscular fitness and cardiometabolic risk in children: a mediation analysis

Objective

Muscular fitness levels have been associated with cardiometabolic risk in children, although whether body weight acts as a confounder or as an intermediate variable in this relationship remains controversial. The aim of this study was to examine whether the association between muscular fitness and cardiometabolic risk factors is mediated by body mass index (BMI).

Design and Methods

Cross-sectional study using a sample of 1158 schoolchildren aged 8-11 years from the province of Cuenca, Spain. We measured anthropometrics and biochemical variables and we calculated a muscular fitness index as the sum of z-scores of handgrip dynamometry/weight and standing long jump, and we estimated a previously validated cardiometabolic risk index (CMRI). Linear regression models were fitted for mediation analysis to assess whether the association between muscular fitness and cardiometabolic risk was mediated by BMI.

Results

Children with normal weight (NW) had a better cardiometabolic risk profile than their overweight (OW) or obese (OB) peers after controlling for muscular fitness. Marginal estimated mean±SE values for NW, OW and OB categories of CMRI were -0.75±0.06<0.84±0.10<2.18±0.16 in boys and -0.73±0.06<0.96±0.10<2.71±0.17 in girls, both p<0.001. Children with higher levels of muscular fitness had a better cardiometabolic risk profile (CMRI marginal estimated mean±SE 1.04±0.13>0.05±0.09>-1.16±0.13 for lower, middle and upper quartiles of muscular fitness in boys and 1.01±0.16>0.10±0.09>-1.02±0.15 in girls, both p<0.001), but differences disappeared when controlling for BMI. BMI acted as a full mediator between muscular fitness and most cardiometabolic risk factors (Sobel test z=-11.44 for boys; z=-11.83 for girls; p<0.001 in CMRI mediation model) and as a partial mediator in the case of waist circumference (Sobel test z=-14.86 for boys; z=-14.51 for girls; p<0.001).

Conclusions

BMI mediates the association between muscular fitness and cardiometabolic risk in schoolchildren. Overall, good muscular fitness is associated with lower cardiometabolic risk, but particularly when accompanied by normal weight.

Roles of physical activity and cardiorespiratory fitness on sex difference in insulin resistance in late elementary years

PURPOSE

Little is known about the potential role of lifestyle factors in sex differences in insulin resistance in late elementary school children.

METHODS

In this cross-sectional study, we compared sex differences in Tanner scales, body fat, physical activity (PA) and fitness, and insulin resistance markers in elementary school children (boys, n = 69 and girls, n = 81) aged 12-13 years. Body composition was assessed with a standardized protocol. Cardiorespiratory fitness was measured as oxygen consumption during an incremental treadmill exercise. Fasting blood samples were collected for blood chemistry assays including lipids, glucose, insulin and homeostasis model assessment for insulin resistance (HOMA-IR), leptin, and adiponectin. Daily PA was measured with an accelerometer for 7 consecutive days, and they were classified as low-, moderate-, and vigorous-PA. Independent t-tests were used to compare mean differences in the measured variables between boys and girls. There were significant sex differences in Tanner scales, body mass index, percent body fat, and waist circumference (WC).

RESULTS

Girls had significantly higher values in Tanner scales (p < 0.001) and percent body fat (p < 0.001) than boys. Boys had significantly higher values in body mass index (p = 0.019) and waist circumference (p < 0.001) than girls. Boys also had significantly higher values in VO2max (p < 0.001) and low (p < 0.001), moderate (p < 0.001), and vigorous (p < 0.001) PAs. With respect to metabolic risk factors, girls had significantly higher serum levels of triglycerides (p = 0.005), insulin (p < 0.001), and HOMA-IR (p < 0.001) and significantly lower high-density lipoprotein cholesterol (p = 0.015) than boys.

CONCLUSION

In summary, the current findings of the study showed that the increased risk for insulin resistance in girls over boys is associated with higher Tanner scale and percent body fat in conjunction with poor cardiorespiratory fitness and physical inactivity, suggesting that exercise intervention to promote physical activity and fitness is imperative for general health promotion of school children, with a special focus on girls.

Advances in pubertal growth and factors influencing it: Can we increase pubertal growth?

Puberty is a period of development characterized by partially concurrent changes which includes growth acceleration, alteration in body composition and appearance of secondary sex characteristics. Puberty is characterized by an acceleration and then deceleration in skeletal growth. The initiation, duration and amount of growth vary considerably during the growth spurt. Pubertal growth and biological maturation are dynamic processes regulated by a variety of genetic and environmental factors. Changes in skeletal maturation and bone mineral accretion concomitant with the stage of pubertal development constitute essential components in the evaluation of growth during this pubertal period. Genetic, endocrine and nutritional factors and ethnicity contribute variably to the amount of growth gained during this important period of rapid changes. Many studies investigated the possibility of increasing pubertal growth to gain taller final adult height in adolescents with idiopathic short stature (ISS). The pattern of pubertal growth, its relation to sex maturity rating and factors affecting them has been addressed in this review. The results of different trials to increase final adult height of adolescents using different hormones have been summarized. These data enables Endocrinologists to give in-depth explanations to patients and families about the efficacy and clinical significance as well as the safety of using these therapies in the treatment of adolescents with ISS.

Palmar crease release and secondary full-thickness skin grafts for contractures in primary full-thickness skin grafts during growth spurts in pediatric palmar hand burns

Pediatric palmar hand burns are a difficult problem because of the serious hand deformity, with functional impairment resulting from rapid growth. In cases of severe pediatric palmar hand burns, a secondary full-thickness skin graft after a primary full-thickness skin graft offers a reliable way of obtaining the required functional and aesthetic outcomes.This study retrospectively evaluated 28 children who required palmar crease releases and secondary full-thickness skin grafts during the past 12 years. The case records were reviewed for sex and age distributions, injury mechanism, and time interval between the primary and secondary full-thickness skin grafts. Surgical procedures included secondary full-thickness skin grafts and incisional releases of grafted skin on the involved creases. There were 19 men and 9 women. The mean age at the time of the burn injury was 10.1 months (range, 5-19 months). The mean age at the time of the secondary full-thickness skin graft was 8.3 years (range, 3-17 years). The most common mechanism of burn injury was steam (n = 24). The median time interval from the primary to the secondary full-thickness skin graft was 67 months (range, 8-156 months). The number of released creases was 81. The number of palmar web contractures in 23 patients was 52. A secondary full-thickness skin graft was more frequently necessary in patients with a primary full-thickness skin graft in the proximal digital crease and palmar web areas. All patients achieved adequate digital length and palmar web contour after surgery. Our patients should be observed until the rapid pubertal growth period.

Constitutional delay influences the auxological response to growth hormone treatment in children with short stature and growth hormone sufficiency

In a retrospective, population based cohort study, we examined whether constitutional delay was associated with the growth response to growth hormone (GH) in children with short stature and normal GH responses. 70 patients were treated with 21 GH iu/m2/week from 1975 to 2013 throughout New Zealand. Demographic and auxological data were prospectively collected and standard deviation scores (SDS) were calculated for height (HtSDS), yearly growth velocity (GV-SDS), body mass index (BMI-SDS) and predicted adult height (PAH-SDS) at time of the last available bone age. In the first year, GH was associated with marked increase in HtSDS (+0.46 (0.19, 0.76), p < 0.001) and GV-SDS (from −1.9 (−3.6, −0.7) to +2.7 (0.45, 4.2), p < 0.001). The increase in HtSDS but not in GV-SDS was greatest with younger patients and greater bone age delay, with no effect of sex, BMI-SDS or baseline HtSDS. PAH-SDS increased with treatment (+0.94 (0.18, 1.5)); increased PAH-SDS was associated with less bone age delay and greater initial increase in HtSDS. This study shows that greater bone age delay was associated with greater initial improvement in height but less improvement in predicted adult heights, suggesting that children with very delayed bone ages may show accelerated maturation during GH treatment.

Diffusion-tensor imaging of the growing ends of long bones: pilot demonstration of columnar structure in the physes and metaphyses of the knee

PURPOSE

To determine the feasibility of using in vivo diffusion-tensor imaging and tractography of the physis to examine changes related to rate of growth, location, and age.

MATERIALS AND METHODS

This retrospective study was institutional review board approved and HIPAA compliant and the requirement for informed consent was waived. Diffusion-tensor imaging of the knee was performed at 3.0 T in 31 subjects (nine boys and 22 girls) with a median age of 13.6 years. The mean ages of boys and girls were 14.7 years (range, 12.0-18.3 years) and 13.2 years (range, 7.0-18.6 years), respectively. Regions of interest were placed in the physis of the tibia and femur, and in the epiphyseal and articular cartilage of these bones. Tractography was performed by using a fractional anisotropic threshold of 0.15 and an angle threshold of 40°. The tractographic patterns were qualitatively evaluated and changes related to age were described. The tract-based apparent diffusion coefficient, fractional anistropy, tensor eigenvalues, and tract length were measured. Diffusion parameters were compared between the center and periphery of the physis, and between the distal femur and proximal tibia.

RESULTS

Tractography resulted in parallel tracts in the physis and the adjacent metaphysis. Tractographic pattern changed with age, with individuals approaching physeal closure having shorter tracts in a random arrangement. Patterns of tractography varied with age in the femur (P < .001) and tibia (P < .001). Femoral tracts (median length, 6.5 mm) were longer than tibial tracts (median length, 4.3 mm) (P < .001). Tracts in the periphery of the physes were longer than those in the center (femur, P = .005; tibia, P = .004). In the physis of the femur and tibia, a significant age-related decrease was observed in apparent diffusion coefficient (P < .001 for both), axial diffusion (femur, P = .001; tibia, P < .001), and transverse diffusion [P < .001 for both]), and an age-related increase was seen in fractional anistropy (P < .001, for both).

CONCLUSION

Diffusion-tensor imaging shows the columnar microstructure of the physis and adjacent metaphysis, and provides further insight into normal growth.

Evolutionary conservation and modulation of a juvenile growth-regulating genetic program

Body size varies enormously among mammalian species. In small mammals, body growth is typically suppressed rapidly, within weeks, whereas in large mammals, growth is suppressed slowly, over years, allowing for a greater adult size. We recently reported evidence that body growth suppression in rodents is caused in part by a juvenile genetic program that occurs in multiple tissues simultaneously and involves the downregulation of a large set of growth-promoting genes. We hypothesized that this genetic program is conserved in large mammals but that its time course is evolutionarily modulated such that it plays out more slowly, allowing for more prolonged growth. Consistent with this hypothesis, using expression microarray analysis, we identified a set of genes that are downregulated with age in both juvenile sheep kidney and lung. This overlapping gene set was enriched for genes involved in cell proliferation and growth and showed striking similarity to a set of genes downregulated with age in multiple organs of the juvenile mouse and rat, indicating that the multiorgan juvenile genetic program previously described in rodents has been conserved in the 80 million years since sheep and rodents diverged in evolution. Using microarray and real-time PCR, we found that the pace of this program was most rapid in mice, more gradual in rats, and most gradual in sheep. These findings support the hypothesis that a growth-regulating genetic program is conserved among mammalian species but that its pace is modulated to allow more prolonged growth and therefore greater adult body size in larger mammals.

Age-based reference ranges for annual height velocity in US children

OBJECTIVE

Clinicians caring for children rely on measures of linear growth as a biomarker of development and overall health. Current reference ranges for height velocity (HV) for US children are unable to provide HV percentiles or Z-scores for early maturing and late maturing children at ages other than age at peak velocity. We present empirically acquired, age-specific reference ranges for HV from a contemporary sample of US youth.

STUDY DESIGN

Subjects were enrolled in the Bone Mineral Density in Childhood Study, a large, multicenter, multiethnic, contemporary cohort of children (aged 5-19 y at enrollment) from the United States followed for up to 7 years. More than 4000 annual (12 ± 1 mo) HV measurements from approximately 1500 children were available. Pubertal status was determined by breast stage or testicular volume assessed by experienced health providers. Age-specific reference ranges were determined using the LMS method.

RESULTS

Reference ranges (third to 97th percentiles) were generated for the entire cohort and for subgroups whose pubertal timing was defined as "earlier," "average," or "later." African American girls experienced earlier pubertal onset and had greater HV at younger ages and lower HV at older ages, compared to non-African American girls; differences did not persist after adjustment for pubertal timing. These differences were not observed for males.

CONCLUSIONS

These reference ranges for annual HV can be used to assess growth relative to peers of the same age and sex, with consideration of pubertal timing. Z-scores and exact percentiles for HV can also be determined for population studies.

Etiologies and early diagnosis of short stature and growth failure in children and adolescents

Accurate measurement of height and weight using standardized techniques is a fundamental component of pediatric medical visits. Calculation of height velocity over time enables comparison with standardized growth charts to identify potential deviations from normal. Growth deviations may be expressed as SD from the normal population mean for children of comparable age and sex; children with heights >2 SD below the mean are generally classified as short stature. In a child with suspected impaired growth, a detailed evaluation should be conducted to identify the cause. Such an evaluation may include a combination of personal, family, and social history; physical examination; general and perhaps specialized laboratory evaluations; radiologic examinations; genetic testing; and consultation with a pediatric subspecialist, such as a pediatric endocrinologist. Variants of normal growth include familial short stature, constitutional delay of growth and puberty, and small for gestational age with catch-up growth. Pathological causes of abnormal growth include many systemic diseases and their treatments, growth hormone deficiency, and a series of genetic syndromes, including Noonan syndrome and Turner syndrome. Children with short stature in whom no specific cause is identified may be diagnosed with idiopathic short stature. Early identification of abnormal growth patterns and prompt referral to specialist care offer children with growth failure and/or short stature the greatest chance for appropriate diagnosis, treatment, and improved clinical outcomes.

Anterior cruciate ligament injuries: diagnosis, treatment, and prevention

The number of anterior cruciate ligament (ACL) injuries reported in athletes younger than 18 years has increased over the past 2 decades. Reasons for the increasing ACL injury rate include the growing number of children and adolescents participating in organized sports, intensive sports training at an earlier age, and greater rate of diagnosis because of increased awareness and greater use of advanced medical imaging. ACL injury rates are low in young children and increase sharply during puberty, especially for girls, who have higher rates of noncontact ACL injuries than boys do in similar sports. Intrinsic risk factors for ACL injury include higher BMI, subtalar joint overpronation, generalized ligamentous laxity, and decreased neuromuscular control of knee motion. ACL injuries often require surgery and/or many months of rehabilitation and substantial time lost from school and sports participation. Unfortunately, regardless of treatment, athletes with ACL injuries are up to 10 times more likely to develop degenerative arthritis of the knee. Safe and effective surgical techniques for children and adolescents continue to evolve. Neuromuscular training can reduce risk of ACL injury in adolescent girls. This report outlines the current state of knowledge on epidemiology, diagnosis, treatment, and prevention of ACL injuries in children and adolescents.

The diagnostic value of first-voided urinary LH compared with GNRH-stimulated gonadotropins in differentiating slowly progressive from rapidly progressive precocious puberty in girls

OBJECTIVE

Characterization of pubertal progression is required to prevent unnecessary intervention in unsustained or slowly progressive (SP) precocious puberty (PP), while delivering hormonal suppression in rapidly progressive (RP) PP. We aimed to assess the diagnostic value of first-voided urinary LH (ULH) compared with GNRH-stimulated gonadotropins in differentiating these forms of PP.

METHODS

A total of 62 girls with PP underwent both GNRH stimulation and ULH assay. Fifteen girls with peak LH ≥ 10 IU/L started treatment immediately, whereas the other 47 girls were evaluated after 6 months for pubertal advancement, height acceleration, and bone-age maturation. Based on these criteria, the participants were assigned to five subgroups: pubertal regression, no progression or progression by one, two or three criteria. The first three subgroups were defined as SP-PP (n=29), while the other two subgroups were defined as RP-PP (n=18). An additional 23 prepubertal girls were evaluated for ULH.

RESULTS

ULH but not serum gonadotropins could distinguish girls with two and three criteria from less progressive subgroups. By comparison with SP-PP (i.e. regression group and groups 0 and 1), those with RP-PP (group 2+3) had lower peak FSH (9.28±2.51 vs 12.57±4.30; P=0.007) and higher peak LH:FSH ratio (0.42±0.30 vs 0.22±0.12; P=0.022) and ULH (1.63±0.65 vs 1.05±0.26 IU/l; P<0.001). Based on receiver operating characteristics analysis, a ULH cutoff of 1.16 IU/l had a better sensitivity (83%) and positive and negative predictive values (65 and 88% respectively) than the other two parameters, with a specificity of 72%.

CONCLUSIONS

ULH assay is a noninvasive, reliable method that can assist in the distinction between SP- and RP-PP.

Nutritional status and growth in Korean children with Crohn's disease: a single-center study

Background/Aims

Malnutrition and growth retardation are important issues in treating pediatric Crohn’s disease (CD). Thus, we aimed to investigate the prevalence of various nutritional and growth parameters at the time of diagnosis in Korean children with CD.

Methods

Seventy-one children (<18 years) were enrolled. We analyzed the Z-scores of height-for-age (HAZ), weight-for-height (WHZ), body mass index for age (BMIZ), bone mineral density for age (BMDZ), and the biochemical markers measured at the time of diagnosis.

Results

At diagnosis, HAZ <−2 was observed in three patients (4%), WHZ <−2 in 20 patients (28%), BMIZ <−2 in 19 patients (27%), and BMDZ <−2 in 11 patients (18%). The HAZ was significantly lower in females and patients with extraintestinal manifestations, and the WHZ and BMIZ were significantly lower in patients with stricturing and penetrating disease. Subnormal serum levels were highly prevalent for hemoglobin, albumin, iron, ferritin, calcium, magnesium, folate, vitamin B₁₂, and zinc. There was a significant correlation between nutritional status, growth retardation, and disease activity.

Conclusions

Abnormal nutritional status was highly prevalent in Korean children with CD at the time of diagnosis and was associated with the extent, behavior, and activity of the disease.

Prepubertal children with growth hormone deficiency treated for four years with growth hormone experience dose-dependent increase in height, but not in the rate of puberty initiation

BACKGROUND/AIMS

Limited data exist on long-term dose response to recombinant human growth hormone (rhGH) in prepubertal GH-deficient (GHD) children. The effect of low, intermediate, and high-dose rhGH (25, 50, and 100 μg/kg/day, respectively) on growth and puberty in children with GHD was investigated for 48 months.

METHODS

A prospective, dose-response study in 111 patients (aged 3-16 years) evaluated growth velocity (cm/year), height standard deviation score (HSDS), corrected HSDS, bone age/chronologic age ratio, body mass index SDS, and the percentage starting puberty.

RESULTS

Dose-related increases were observed in growth velocity (p < 0.001), HSDS (p < 0.001), and corrected HSDS (p < 0.001) from baseline to 48 months. Increases in the bone age/chronologic age ratio (p = 0.043) and body mass index SDS (p = 0.018) occurred up to 36 months at intermediate and high doses versus low-dose rhGH; increases at 48 months were not significant. No significant differences in growth were found between intermediate and high doses of rhGH. Percentages of rhGH-treated patients starting puberty at each dose were equivalent (p = 0.607).

CONCLUSIONS

rhGH, 50 and 100 μg/kg/day, induced greater growth than 25 μg/kg/day without altering the proportion of children starting puberty. The maximum approved dose for pubertal patients (100 μg/kg/day) is not required or recommended for prepubertal children with GHD.

Reduced forced expiratory flow but not increased exhaled nitric oxide or airway responsiveness to methacholine characterises paediatric sickle cell airway disease

BACKGROUND

Asthma and airway hyper-responsiveness are reportedly more common in children with sickle cell disease (SCD).

AIM

To determine airway responsiveness, airway inflammation and clinical features of asthma in SCD.

METHODS

A prospective, single-centre study of 50 SCD children without overt pulmonary vascular disease and 50 controls. Exhaled nitric oxide (FeNO) and total serum IgE were measured and spirometry and methacholine challenge were performed. The methacholine dose-response slope (DRS) was calculated.

RESULTS

Doctor diagnosis of asthma was made in 7 (14%) SCD versus 12 (24%) control subjects (p=0.203). FeNO levels were similar in SCD and controls (p=0.250), and were higher in those with atopy and an asthma diagnosis (OR 4.33, 95% CI 1.7 to 11.1; p<0.05). zFEV1 (p=0.002) and zFEV1/FVC (p=0.003) but not zFVC (p=0.098) were lower in SCD versus controls. DRS was higher in those with asthma (p=0.006) but not in SCD versus controls (p=0.403). DRS correlated with FeNO and blood eosinophil count in controls but not SCD. In SCD, DRS was higher in those admitted to hospital with respiratory symptoms (n=27) versus those never admitted (n=23) (p=0.046). DRS was similar in those with at least one acute chest syndrome episode (n=12) versus those with none (n=35) (p=0.247).

CONCLUSIONS

SCD children have airflow obstruction despite having minimal evidence of pulmonary vascular disease. Airflow obstruction is not associated with increased methacholine sensitivity or eosinophilic inflammation, at least as judged by FeNO. Airflow obstruction in SCD does not appear to be related to childhood eosinophilic asthma, but its pathophysiology remains ill understood.

Co-morbidity resolution in morbidly obese children and adolescents undergoing sleeve gastrectomy

BACKGROUND

Bariatric surgery is becoming important for the reversal of co-morbidities in children and adolescents. We previously reported the safety and efficacy of laparoscopic sleeve gastrectomy (LSG) in the pediatric population. However, evidence pertaining to the effect of LSG on co-morbidities in this age group is scarce. The objective of this study was to assess the remission and improvement of co-morbidities (dyslipidemia, hypertension, diabetes, and obstructive sleep apnea) after LSG in children and adolescents.

METHODS

Anthropometric changes, complications, remission, and improvement in co-morbidities were assessed over 3 years. OSA was diagnosed using the Pediatric Sleep Questionnaire (PSQ) and polysomnography and its resolution was assessed according to PSQ score alone. Diabetes, prediabetes, hypertension, prehypertension, and dyslipidemia were assessed using standard pediatric-specific definitions.

RESULTS

The review yielded 226 patients; 74 patients were prepubertal (5-12 yr of age, mean: 9.8±2.3), 115 adolescents (13-17 yr of age, mean: 15.4±1.7), and 37 were young adults (18-21 yr of age, mean: 19.2±.8). Overall mean age was 14.4±4.0 years (range: 4.94-20.99), and 50.4% were females. Mean body mass index (BMI) and BMI z score were 48.2±10.1 kg/m(2) and 2.99±.35, respectively. Mean BMI z score at 1, 2, and 3 years postoperative was 2.01±.87, 2.00±1.07, and 1.66±.65, respectively. Mean preoperative height was 158.0±15.1 cm, and at 1, 2, and 3 years postoperative, it was 160.3±13.4, 161.4±14.1, and 163.2±11.1, respectively. All patients at different age groups experienced normal growth velocity. Within 2 years of follow-up, 90.3% of co-morbidities were in remission or improved, 64.9% of which were within the first 3 months postoperatively. No further improvement or remission was observed beyond 2 years, and there was no recurrence up to 3 years in patients who were seen in follow-up. The lost to follow-up in each of the 3 years was 4.2%, 7.6%, and 15.3%, respectively.

CONCLUSION

LSG performed on children and adolescents results in remission or improvement of>90% of co-morbidities within 2 years after bariatric surgery with few complications, no mortality, and normal growth.

Nutritional management and follow up of infants and children with food allergy: Italian Society of Pediatric Nutrition/Italian Society of Pediatric Allergy and Immunology Task Force Position Statement

Although the guidelines on the diagnosis and treatment of food allergy recognize the role of nutrition, there is few literature on the practical issues concerning the nutritional management of children with food allergies. This Consensus Position Statement focuses on the nutritional management and follow-up of infants and children with food allergy.It provides practical advices for the management of children on exclusion diet and it represents an evidence-based consensus on nutritional intervention and follow-up of infants and children with food allergy. Children with food allergies have poor growth compared to non-affected subjects directly proportional to the quantity of foods excluded and the duration of the diet. Nutritional intervention, if properly planned and properly monitored, has proven to be an effective mean to substantiate a recovery in growth. Nutritional intervention depends on the subject's nutritional status at the time of the diagnosis. The assessment of the nutritional status of children with food allergies should follow a diagnostic pathway that involves a series of successive steps, beginning from the collection of a detailed diet-history. It is essential that children following an exclusion diet are followed up regularly. The periodic re-evaluation of the child is needed to assess the nutritional needs, changing with the age, and the compliance to the diet. The follow- up plan should be established on the basis of the age of the child and following the growth pattern.

The Relationship between Subnormal Peak-Stimulated Growth Hormone Levels and Auxological Characteristics in Obese Children

CONTEXT

The hypothesis that obese children are overdiagnosed with growth hormone deficiency (GHD) has not been adequately investigated in the context of adiposity-related differences in auxology.

AIM

To investigate the differences in auxological parameters between short, prepubertal, obese children, and normal-weight peers who underwent growth hormone stimulation testing (GHST).

HYPOTHESIS

Over-weight/obese children with GHD [peak growth hormone (GH) < 10 μg/L] will have higher values for growth velocity (GV) standard deviation score (SDS), bone age minus chronological age (BA - CA), and child height SDS minus mid-parental height (MPTH) SDS when compared to normal-weight GHD peers.

SUBJECTS AND METHODS

A retrospective review of anthropometric and provocative GHST data of 67 prepubertal, GH-naïve children of age 10.21 ± 2.56 years (male n = 45, age 10.8 ± 2.60 years; female n = 22, age 8.94 ± 2.10).

INCLUSION CRITERIA

GHST using arginine and clonidine.

EXCLUSION CRITERIA

hypopituitarism, abnormal pituitary magnetic resonance imaging scan, syndromic obesity, or syndromic short stature. Data were expressed as mean ± SD.

RESULTS

The over-weight/obese children with peak GH of <10 μg/L had significantly lower value for natural log (ln) peak GH (1.45 ± 0.09 vs. 1.83 ± 0.35, p = 0.022), but similar values for GV SDS, insulin-like growth factor-I, insulin-like growth factor binding protein-3, bone age, BA - CA, MPTH, and child height SDS minus MPTH SDS compared to normal-weight peers with GHD. After adjusting for covariates, the over-weight/obese children (BMI ≥ 85th percentile) were >7 times more likely than normal-weight subjects (BMI < 85th percentile) to have a peak GH of <10 μg/L, and 23 times more likely to have a peak GH of <7 μg/L (OR = 23.3, p = 0.021). There was a significant inverse relationships between BMI SDS and the ln of peak GH (β = -0.40, r (2) = 0.26, p = 0.001), but not for BMI SDS vs. GV SDS, ln peak GH vs. BA, or ln peak GH vs. GV SDS.

CONCLUSION

Subnormal peak GH levels in obese prepubertal children are not associated with unique pre-GHST auxological characteristics.

Age of thelarche and menarche in contemporary US females: a cross-sectional analysis

AIM

A recent secular trend towards earlier thelarche has been suggested. The aim of this study is to examine normative ages of thelarche and menarche in contemporary US females.

METHODS

Trained physicians documented Tanner breast stage by observation in a cross-sectional cohort. Age of menarche was self-reported. The subjects were healthy female children and adolescents. The mean age of thelarche was determined by probit analysis and the mean age of menarche was determined by using a normal time-to-event model.

RESULTS

Mean age of thelarche was 9.7 years among 610 females aged 3.0-17.9 years (70% non-Hispanic Caucasian (NHC), 14% African-Americans, 7% Hispanic, 9% "other"). The mean age of menarche was 12.8 years for NHC, with African-Americans having menarche 0.6 years earlier.

CONCLUSIONS

Thelarche occurred earlier than recently reported, while age of menarche remained unchanged, this supported a persistent secular trend towards earlier thelarche but stable age of menarche. This suggests that the observed thelarche is gonadotropin-independent or the tempo of pubertal advancement has slowed.

Age at menarche among in-school adolescents in Sawla Town, South Ethiopia

BACKGROUND

Although a declining trend in age at menarche has been observed in developed countries over decades commonly attributed to childhood excessive weight gain and sedentary life, little is known about this case in the developing countries.

METHODS

A cross-sectional study design and multistage sampling was used to include 660 school adolescents for analysis. Data collection included weight and height measurements. Multinomial logistic regression analyses were done for early and late age of menarche, in reference to average age at menarche, to measure the association of age at menarche with some socio-demographic variables and body habits.

RESULTS

The mean age at menarche was 13.9±1.2 years (95%CI, 13.8-14.0). The menarche ages ranged between 10 and 12 years for 10.5%, 13 and 14 years for 54.5%, and 15+ years for 35%. Low menarche age was independently associated with high calorie consumption, high protein diet, more coffee intake, low physical activity and parents' low educational background. Low body mass index, low parents' income, exercise, and Amhara ethnic background were associated with late menarche age.

COCLUSION

The mean menarche age found in this study was higher than the report from developed countries. But, the proportion of adolescents with low menarche age was comparable with reports from developed countries. Inactive adolescents were more likely to see menarche earlier than average age. Healthy eating habits, regular exercise and nutrition education need to be promoted among school children.

Left ventricular mass by echocardiographic measures in children and adolescents

BACKGROUND

Recent evidence in adults suggests that left ventricular mass measured as left ventricular mass/height predicts cardiovascular morbidity and mortality better than the two widely used indices, left ventricular mass/body surface area and left ventricular mass/height Standards of left ventricular mass/height have not been reported in children, for whom, owing to lack of significant cardiovascular morbidity and mortality, body mass index has traditionally been used as a potential cardiovascular risk factor.

METHODS

In this retrospective study, 692 clinically normal children aged 1 day to 18 years underwent detailed echocardiographic assessment to assess whether any of the left ventricular mass indices--left ventricular mass/height, left ventricular mass/body surface area, and left ventricular mass/height--are associated with obesity as measured by body mass index. Correlations, t-tests, and linear regressions were used for statistical testing.

RESULTS

Left ventricular mass/height was better correlated (R2 = 0.36) with body mass index than left ventricular mass/body surface area (R2 = 0.179) and left ventricular mass/height (R2 = 0.006), although all three dependent variables show a significant correlation (p < 0.035). In addition, a higher percentage of obese patients were noted to have elevated left ventricular mass as measured by left ventricular mass/height than by the other two methods.

CONCLUSIONS

Left ventricular mass/height is a reliable indicator of obesity associated left ventricular hypertrophy. Left ventricular mass/height can be used conveniently during transitions from youth to adults for long-term follow-up. These findings support the importance of including left ventricular mass/height in future studies of cardiovascular risks and preventive strategies in children and adolescents.

Longitudinal standards for height and height velocity in Korean children and adolescents: the Kangwha study. [corrected]

Longitudinal standards for height and height velocity are essential to monitor for appropriate linear growth. We aimed to construct standards in Korean children and adolescents through the population-based longitudinal Kangwha study. Our study was a part of a community-based prospective cohort study from 1986 to 1999 with 800 school children. Height and height velocity were recorded annually from age 6 until final height. Results were compared with cross-sectional data from the 2007 Korean National Growth Charts. Final height was 173.5 cm in boys and 160.5 cm in girls. Although final height was similar between longitudinal and cross-sectional standards, the mean height for age was higher in the longitudinal standard by 1-4 cm from age 6 until the completion of puberty. Using the longitudinal standard, age at peak height velocity (PHV) was 12 in boys and 10 in girls; height velocity at PHV was 8.62 cm/yr in boys and 7.07 cm/yr in girls. The mean height velocity was less than 1 cm/yr at age 17 in boys and 15 in girls. Thus, we have presented the first report of longitudinal standards for height and height velocity in Korean children and adolescents by analyzing longitudinal data from the Kangwha cohort.

Pubertal height velocity and associations with prepubertal and adult heights in cystic fibrosis

OBJECTIVES

To test the hypothesis that pubertal peak height velocity (PHV) in cystic fibrosis (CF) has improved and is influenced by prepubertal growth and genetic potential.

STUDY DESIGN

PHV from 1862 children born in 1984-87 and documented in the 1986-2008 US CF Foundation Registry was determined by statistical modeling and classified into normal, delayed (2-SD > average age), attenuated (magnitude <5th percentile), or both delayed and attenuated (D&A). Genetic potential for height was estimated by parental stature.

RESULTS

PHV averaged 8.4 cm/year at age 14.0 years in boys and 7.0 cm/year at age 12.1 years in girls, ∼6-month delay and ∼15% reduction compared with healthy children. PHV was normal in 60%, delayed in 9%, attenuated in 21%, and D&A in 5%. Patients with delayed PHV reached similar adult height percentile (boys: 34th, girls: 46th) to those with normal PHV (boys: 33rd, girls: 34th); both were significantly taller than the attenuated (boys: 11th, girls: 19th) and D&A PHV subgroups (boys: 8th, girls: 14th). Pancreatic-sufficient patients had taller prepubertal and adult heights but similar PHV compared with pancreatic-insufficient or meconium ileus patients. Adjusting for genetic potential reduced adult height percentiles more in boys (from 25th to 16th) than girls (from 28th to 24th). Height at age 7 years, PHV age and magnitude, and parental stature significantly predicted adult height.

CONCLUSIONS

Pubertal PHV has improved in children with CF born after mid-1980s compared with older cohorts but remains below normal. Suboptimal prepubertal and pubertal growth led to adult height below genetic potential in CF.

Influences on the onset and tempo of puberty in human beings and implications for adolescent psychological development

This article is part of a Special Issue "Puberty and Adolescence". Historical records reveal a secular trend toward earlier onset of puberty in both males and females, often attributed to improvements in nutrition and health status. The trend stabilized during the mid 20th century in many countries, but recent studies describe a recurrence of a decrease in age of pubertal onset. There appears to be an associated change in pubertal tempo in girls, such that girls who enter puberty earlier have a longer duration of puberty. Puberty is influenced by genetic factors but since these effects cannot change dramatically over the past century, environmental effects, including endocrine disrupting chemicals (EDCs), and perinatal conditions offer alternative etiologies. Observations that the secular trends in puberty in girls parallel the obesity epidemic provide another plausible explanation. Early puberty has implications for poor behavioral and psychosocial outcomes as well as health later in life. Irrespective of the underlying cause of the ongoing trend toward early puberty, experts in the field have debated whether these trends should lead clinicians to reconsider a lower age of normal puberty, or whether such a new definition will mask a pathologic etiology.

Body size regulation and insulin-like growth factor signaling

How animals achieve their specific body size is a fundamental, but still largely unresolved, biological question. Over the past decades, studies on the insect model system have provided some important insights into the process of body size determination and highlighted the importance of insulin/insulin-like growth factor signaling. Fat body, the Drosophila counterpart of liver and adipose tissue, senses nutrient availability and controls larval growth rate by modulating peripheral insulin signaling. Similarly, insulin-like growth factor I produced from liver and muscle promotes postnatal body growth in mammals. Organismal growth is tightly coupled with the process of sexual maturation wherein the sex steroid hormone attenuates body growth. This review summarizes some important findings from Drosophila and mammalian studies that shed light on the general mechanism of animal size determination.

Effect of topiramate monotherapy on height in newly diagnosed children with epilepsy

We conducted a post hoc assessment of the effect of ≥6 months of topiramate monotherapy on height in pediatric patients with newly diagnosed partial-onset seizure. Data on height measured nonsystematically up to 4 years from two randomized, double-blind studies and their open-label extensions were combined and converted to z scores and percentiles by patient's sex and age. Height velocity values (centimeters per year) and the associated z scores were computed for each postbaseline year using normative data. Median height velocity (centimeters per year) values and the associated z scores for patients ages 6-9 years were, year 1: 4.7 (-0.91); year 2: 4.2 (-1.62); year 3: 4.5 (-1.87); and for patients ages 10-15 years were, year 1: 4.0 (-0.76); year 2: 2.8 (-1.34); year 3: 3.1 (-0.74). There was a significant correlation between height velocity z score and change from baseline in height z score (r = 0.94 [n = 117]; P < 0.0001). Patient's bicarbonate status (low was defined as two postbaseline serum bicarbonate values <20 mmol/L) and sex had no effect on height velocity. In both age groups, continued growth was observed; however, the growth rate was slower than expected compared with a matched normal population from years 1 to 2 and showed minimal recovery from years 2 to 3.

Parental attitudes toward fertility preservation in boys with cancer: context of different risk levels of infertility and success rates of fertility restoration

OBJECTIVE

To measure the parental attitudes toward fertility preservation in boys with cancer.

DESIGN

Retrospective cohort study.

SETTING

Questionnaire survey via regular mail.

PATIENT(S)

A total of 465 families whose sons were already treated for cancer.

INTERVENTION(S)

The questionnaire was designed for two groups based on child's age at the time of cancer diagnosis: <12 and ≥12 years old.

MAIN OUTCOME MEASURE(S)

Descriptive statistics regarding a positive or negative attitude of parents toward fertility preservation options in the context of different risk levels of infertility and success rates of fertility restoration.

RESULT(S)

The response rate was 78%. Sixty-four percent of parents of boys ≥12 years old would agree to store sperm obtained by masturbation and/or electroejaculation, and 54% of parents of boys <12 years old would agree to store a testicular biopsy. If the risk of infertility or the success rate of fertility restoration were ≤20%, more than one-fourth of parents would still opt for fertility preservation.

CONCLUSION(S)

All parents should be counseled about the risks of infertility due to cancer treatment, because many parents want to preserve their son's fertility even if the risk of becoming infertile or the chances on fertility restoration are low.

Pathophysiological insights derived by natural history and motor function of spinal muscular atrophy

OBJECTIVE

To examine the natural history of spinal muscular atrophy (SMA) to gain further insight into the clinical course and pathogenesis.

STUDY DESIGN

Survival pattern, age of onset, and ambulatory status were retrospectively analyzed in 70 patients with SMA with deletions of the survival motor neuron 1 genes that presented to a specialized neuromuscular clinic. The Kaplan-Meier method was used to obtain survival curves. Hammersmith Functional Motor Scale-Expanded and abductor pollicis brevis compound muscle action potential amplitudes were assessed in 25 of the surviving cohort and correlated with survival motor neuron 2 copy number.

RESULTS

Survival probabilities at ages 1, 2, 4, 10, 20, and 40 years were 40%, 25%, 6%, and 0%, respectively, for patients with SMA type 1; 100%, 100%, 97%, 93%, 93%, and 52% for patients with SMA type 2 and all patients with SMA type 3 were alive (age range 7-33 years). There were significant associations between age of onset and long-term outcome, specifically survival in SMA type 1 (P < .01) and Hammersmith Functional Motor Scale-Expanded (P < .0001), and compound muscle action potential (P = .001) in SMA types 2 and 3. Motor function in patients with long-standing SMA reduced over prolonged periods or remained stable. Survival motor neuron 2 copy number related to continuing changes in motor function with age.

CONCLUSION

The natural history of SMA suggests considerable early loss of motor neurons, with severity related to differences in the number of remaining motor neurons. As the ensuing chronic course in milder phenotypes suggests relative stability of remaining motor neurons, the maximal therapeutic window presents early.

Body-composition reference data for simple and reference techniques and a 4-component model: a new UK reference child

BACKGROUND

A routine pediatric clinical assessment of body composition is increasingly recommended but has long been hampered by the following 2 factors: a lack of appropriate techniques and a lack of reference data with which to interpret individual measurements. Several techniques have become available, but reference data are needed.

OBJECTIVE

We aimed to provide body-composition reference data for use in clinical practice and research.

DESIGN

Body composition was measured by using a gold standard 4-component model, along with various widely used reference and bedside methods, in a large, representative sample of British children aged from 4 to ≥20 y. Measurements were made of anthropometric variables (weight, height, 4 skinfold thicknesses, and waist girth), dual-energy X-ray absorptiometry, body density, bioelectrical impedance, and total body water, and 4-component fat and fat-free masses were calculated. Reference charts and SD scores (SDSs) were constructed for each outcome by using the lambda-mu-sigma method. The same outcomes were generated for the fat-free mass index and fat mass index.

RESULTS

Body-composition growth charts and SDSs for 5-20 y were based on a final sample of 533 individuals. Correlations between SDSs by using different techniques were ≥0.68 for adiposity outcomes and ≥0.80 for fat-free mass outcomes.

CONCLUSIONS

These comprehensive reference data for pediatric body composition can be used across a variety of techniques. Together with advances in measurement technologies, the data should greatly enhance the ability of clinicians to assess and monitor body composition in routine clinical practice and should facilitate the use of body-composition measurements in research studies.

Comparison of detection of normal puberty in boys by a hormonal sleep test and a gonadotropin-releasing hormone agonist test

CONTEXT

The magnitude of sleep-related gonadotropin rise required to activate pubertal gonadal function is not established.

OBJECTIVE

Our objective was to determine the normal relationship between sleep-related pubertal hormone levels and pituitary-testicular responsiveness to a GnRH agonist (GnRHag) test across the pubertal transition. DESIGN/SETTING AND PARTICIPANTS: We conducted a prospective study in a General Clinical Research Center with healthy 9- to 15-yr-old volunteer boys.

INTERVENTIONS

INTERVENTIONS included overnight blood sampling followed by leuprolide acetate injection (10 μg/kg).

PRIMARY OUTCOME VARIABLES

LH, FSH, and testosterone levels were evaluated.

RESULTS

LH levels during sleep and post-GnRHag rose steadily during the late prepubertal years. Sleep peak LH correlated highly with the LH response to GnRHag across groups (r = 0.913). A sleep peak LH level of at least 3.7 U/liter predicted pubertal testicular activation with 100% accuracy. LH of at least 14.8 and at least 19.0 U/liter 4 h after GnRHag, respectively, predicted puberty with 100% sensitivity/94% specificity and 100% specificity/94% sensitivity. Overweight pubertal boys had transiently prolonged responses to GnRHag. FSH rose during both waking and sleeping hours during the prepubertal years, and all pubertal boys had an FSH level of at least 0.9 U/liter awake and at least 1.2 U/liter asleep. Sleep LH was more closely related than FSH to testicular size.

CONCLUSIONS

These data suggest that a critical LH level during sleep (≥3.7 U/liter) heralds the onset of pubertal virilization and that this level is predictable by LH of at least 14.8-19 U/liter 4 h after GnRHag. These data also suggest that LH stimulation of testicular androgen production plays a role in stimulating testicular tubule growth once a critical level of FSH is achieved.

Neural mechanisms of encoding social and non-social context information in autism spectrum disorder

Individuals with autism spectrum disorder (ASD) often fail to attach context to their memories and are specifically impaired in processing social aspects of contextual information. The aim of the present study was to investigate the modulatory influence of social vs. non-social context on neural mechanisms during encoding in ASD. Using event-related fMRI, 13 boys with ASD and 13 typically developing boys comparable for age and IQ were investigated during encoding of neutral objects presented either with a social (faces) or a non-social (houses) context. A memory paradigm was then applied to identify brain activation patterns associated with encoding of subsequently recollected versus non-recollected objects. On the behavioural level, no significant between-group differences emerged. In particular, no differential effects of context on memory performance were observed. Neurally, however, context-specific group differences were observed in several brain regions. During encoding of subsequently recollected objects presented with a face, ASD subjects (compared to controls) showed reduced neural activation in the bilateral inferior frontal gyrus, bilateral middle frontal gyrus and right inferior parietal lobule. Neural activation in the right inferior frontal gyrus was positively correlated with memory performance in controls, but negatively in ASD individuals. During encoding of subsequently non-recollected objects presented in the non-social context, ASD subjects showed increased activation in the dorsal MPFC. Our findings suggest that in ASD subjects, fronto-parietal brain regions subserving memory formation and the association of contextual information are activated atypically when a social context is presented at encoding. The data add to findings from related research fields indicating that in ASD, socioemotional impairment extends into domains beyond social cognition. Increased activation in the dorsal MPFC in ASD individuals might reflect supervisory cognitive processes related to the suppression of a distracting non-social context.

Linear growth and final height characteristics in adolescent females with anorexia nervosa

OBJECTIVE

Growth retardation is an established complication of anorexia nervosa (AN). However, findings concerning final height of AN patients are inconsistent. The aim of this study was to assess these phenomena in female adolescent inpatients with AN.

METHODS

We retrospectively studied all 211 female adolescent AN patients hospitalized in an inpatient eating disorders department from 1/1/1987 to 31/12/99. Height and weight were assessed at admission and thereafter routinely during hospitalization and follow-up. Final height was measured in 69 patients 2-10 years after discharge. Pre-morbid height data was available in 29 patients.

RESULTS

Patients' height standard deviation scores (SDS) on admission (-0.285±1.0) and discharge (-0.271±1.02) were significantly (p<0.001) lower than expected in normal adolescents. Patients admitted at age ≤13 years, or less than 1 year after menarche, were more severely growth-impaired than patients admitted at an older age, (p = 0.03). Final height SDS, available for 69 patients, was -0.258±1.04, significantly lower than expected in a normal population (p = 0.04), and was more severely compromised in patients who were admitted less than 1 year from their menarche. In a subgroup of 29 patients with complete growth data (pre-morbid, admission, discharge, and final adult height), the pre-morbid height SDS was not significantly different from the expected (-0.11±1.1), whereas heights at the other time points were significantly (p = 0.001) lower (-0.56±1.2, -0.52±1.2, and -0.6±1.2, respectively).

CONCLUSIONS

Our findings suggest that whereas the premorbid height of female adolescent AN patients is normal, linear growth retardation is a prominent feature of their illness. Weight restoration is associated with catch-up growth, but complete catch-up is often not achieved.