New cross sectional stature, weight, and head circumference references for Down's syndrome in the UK and Republic of Ireland

Head circumference percentiles in Indian children with Down syndrome

This study aimed to construct age- and sex-specific growth percentiles for head circumference (HC) that can be used as a reference for Indian children with Down syndrome (DS). Over 24 years, following a mixed-longitudinal growth research design, 2,327 head circumference measurements were performed on 1,125 (boys: 752, girls: 373) children with DS karyotypically proven as cases of free trisomy 21 who were aged <1 month to 10 years, following a standardized anthropometric technique. A steady increase in the mean head circumference of male and female children with DS was noted. Boys with DS had significantly larger HCs than girls. Our study showed that 12.9% of Down syndrome cases had normal head circumference, 27.2% had small heads, and the majority, 59.9%, had microcephaly. Head circumference percentiles for boys and girls with Down syndrome were constructed for ages <1 month to 10 years. There is a need to monitor the growth of children with Down syndrome using population-specific and specialized growth charts. The age- and sex-specific head circumference growth percentiles presented for Indian children with Down syndrome can be used for growth monitoring and inter-population comparison.

Facial growth parameters in Down syndrome: Review of the literature and forensic application for missing persons age progression

PURPOSE

Individuals with Down syndrome (DS) show growth trajectories which deviate from standard ones due to variations in the growth of facial structures. Studying the effect of aging on the faces of DS individuals is necessary to obtain an accurate result through age progression, a technique based on the study of physiognomic features and used in cases of missing persons. Here we present scientific publications that delve into the rhythms of aging and morphological characteristics of facial features in DS individuals to enable appropriate age progression in cases of missing DS individuals.

RESULTS

The scientific literature considered in this review studies the growth of soft tissue and bone substrate by comparing standard growth values with those measured through anthropometric measurements of individuals with DS. Growth trajectories are described by considering morphological trends both by comparing standard values with those found in individuals with DS and by observing individual physiognomic traits.

CONCLUSIONS

When a young individual with DS goes missing, the realization of an age progression requires knowledge of the aging dynamics peculiar to the DS face. Therefore, physical, cognitive, and clinical factors must be considered. Delayed physical development and early aging, such as the onset of puberty and weight gain, have an important impact on the realization of age progression. In fact, depending on the life period to be considered, the effects of aging must be calibrated based on the knowledge gathered from scientific research.

Safety, tolerability, and efficacy of an in-class combination therapy switch from bosentan plus sildenafil to ambrisentan plus tadalafil in children with pulmonary arterial hypertension

The aim of this single-centre retrospective observational study was to evaluate the safety, tolerability, and efficacy of an in-class combination therapy switch from bosentan plus sildenafil to ambrisentan plus tadalafil in children with pulmonary arterial hypertension. Children aged over 5 years who were established on sildenafil plus bosentan were offered to undergo a therapy switch from May 2014 to May 2021 and, if remaining in the service, followed up to May 2024. Children with Eisenmenger syndrome, open intra or extra-cardiac shunt, or with pulmonary hypertension-associated lung disease were excluded. As part of a structured clinical program children were assessed via walk test, echocardiography, cardiac magnetic resonance imaging (CMRI), cardiopulmonary exercise testing, and serum biomarkers. Fifty-two children were included, 33 in the switch group and 19 in the control group. Clinical characteristics at diagnosis and baseline assessments did not differ between groups. All children tolerated the medication switch. Over a median 13.0 [12.0,13.7] week follow-up in the switch group there was a significant improvement in World Health Organization functional class (WHO FC, p < 0.001); reduction in estimated right ventricular systolic pressure by echocardiography of 7 mmHg (p = 0.03) and a 2% increase (p = 0.03) in right ventricular ejection fraction on CMRI. There was a sustained improvement in WHO FC (p < 0.01) in the switch group at medium-term follow-up of 40.9 [35.2,49.3] weeks. Long-term outcome of transplant- or Potts shunt-free survival was comparable between the two groups.

Comparison of Some Anthropometric Parameters and Blood Pressure between Adolescents with Down Syndrome and Healthy Ones

Background

Most of the people with Down syndrome have short stature compared to general population. There is also a high prevalence of overweight and obesity, mainly in the adolescence and in the adult life. The aim of this study was to compare some anthropometric parameters, heart rate and blood pressure of children with Down syndrome and those with normal development. Down syndrome is among the most commonly classified categories of mental sub normality, with the incidence at birth being around 1: 700 and 1: 750 in live births in most countries worldwide, with the risk of increasing with mother's age.

Methods

The sample consisted of 82 children, 32 with Down syndrome and 50 healthy children, male, aged 14-15 yr from the population of Kosovo in 2022. There were no health problems present in the healthy children.

Results

About 53% of children with Down syndrome have normal body mass, 15.62% are overweight, and 21.8 are obese. In terms of blood pressure, Down syndrome children have higher systolic pressure (121.94mm/hg), sd ±21.69 than healthy children (111.18mm/hg, sd ±10.88).

Conclusion

Children with Down syndrome had significantly higher body mass index, heart rate, and systolic pressure at rest compared to healthy children. However, after short physical activity, healthy children exhibited greater diastolic pressure than children with Down syndrome.

Prevalence, associated risk factors, and respiratory event distribution of obstructive sleep apnea in children with Down syndrome

PURPOSE

Children with Down Syndrome (DS) have a high prevalence of obstructive sleep apnea (OSA). We aimed to assess OSA prevalence in a single center cohort of children with DS, identify associated risk factors of obstructive respiratory events, and examine the influence of different sleep stages and body positions on respiratory events distribution.

METHODS

Single center retrospective study that included children with DS who underwent overnight polysomnogram (PSG). OSA severity was categorized by obstructive apnea-hypopnea index (OAHI) as mild (1.5-4.9 events/h), moderate (5-9.9 events/h), and severe (≥ 10 events/h). A logistic regression analysis was used to examine the association between OSA-related risk factors in normal and abnormal OAHI category and in REM and Non-REM predominant AHI groups.

RESULTS

PSG data were available for 192 children with a median age of 5 years (IQR 7). OSA prevalence was 82.3% (27.1% mild, 19.8% moderate, and 35.4% severe). A logistic regression model identified BMI and being an African American as significant predictors for OAHI severity. In children with OSA, the median OAHI was 7.6 and obstructive respiratory events were more common in REM sleep and in the supine position. The median REM OAHI was 20 events/h (IQR: 24.4), whereas the median Non-REM OAHI was 5.2 events/h (IQR: 12.6 p < 0.0001). Similarly, supine OAHI was 11.6 (IQR: 19.3) and off supine OAHI was 6.6 (IQR: 11.6, p = 0.0004). Age was a significant predictor (p = 0.012) for Non-REM predominant OSA which was present in 15.2% of children with OSA.

CONCLUSION

Children with DS have a high prevalence of OSA. Higher BMI and being an African American were significant associated risk factors for higher OAHI. Obstructive respiratory events in children with DS occur predominantly in REM sleep and in the supine position. Non-REM predominant distribution of respiratory events was noted in older children with DS.

From growth charts to growth status: how concepts of optimal growth and tempo influence the interpretation of growth measurements

Growth measurements are largely uninterpretable without comparison to a growth chart. Consequently, the characteristics of a growth chart become an integral component of the interpretation of growth measurements. The concepts of optimal growth and tempo are well recognised by auxologists, yet their implications for interpretation of growth measurements remain problematic. This narrative review discusses the concept of optimal growth and how it serves as a guiding principle in the development and use of growth charts. The challenges of operationalising tempo for growth assessment are also discussed. Illustrative examples highlight the importance of these two central concepts in the use and interpretation of growth measurements.

Fatty liver disease in children (MAFLD/PeFLD Type 2): unique classification considerations and challenges

In children, fatty liver disease is a group of disorders that often overlaps with inherited metabolic disorders (IMDs), which requires prompt diagnosis and specific management. Metabolic dysfunction-associated fatty liver disease (MAFLD) or, formerly, non-alcoholic fatty liver disease (NAFLD) is the hepatic component of a multisystemic disease that requires a positive criteria in metabolic dysfunction for diagnosis. However, in children, the diagnosis of MAFLD is one of the exclusions of an IMD [paediatric fatty liver disease (PeFLD) type 1] including the possibility that an IMD can be identified in the future following investigations that may be negative at the time. Therefore, while children with fatty liver with metabolic dysfunction could be classified as MAFLD (PeFLD type 2) and managed that way, those who do not fulfil the criteria for metabolic dysfunction should be considered separately bearing in mind the possibility of identifying a yet undiagnosed IMD (PeFLD type 3). This concept is ever more important in a world where MAFLD is the most common cause of liver disease in children and adolescents in whom about 7% are affected. The disease is only partially understood, and awareness is still lacking outside hepatology and gastroenterology. Despite its increasing pervasiveness, the management is far from a one-size-fits-all. Increasing complexities around the genetic, epigenetic, non-invasive modalities of assessment, psychosocial impacts, therapeutics, and natural history of the disease have meant that an individualised approach is required. This is where the challenge lies so that children with fatty liver are considered on their own merits. The purpose of this review is to give a clinical perspective of fatty liver disease in children with relevance to metabolic dysfunction.

Hearing impairment in murine model of Down syndrome

Hearing impairment is a cardinal feature of Down syndrome (DS), but its clinical manifestations have been attributed to multiple factors. Murine models could provide mechanistic insights on various causes of hearing loss in DS. To investigate mechanisms of hearing loss in DS in the absence of the cadherin 23 mutation, we backcrossed our DS mice, Dp(16)1Yey, onto normal-hearing CBA/J mice and evaluated their auditory function. Body weights of wild type (WT) and DS mice were similar at 3-months of age, but at 9-months, WT weighed 30% more than DS mice. Distortion product otoacoustic emissions (DPOAE), a test of sensory outer hair cell (OHC) function negatively impacted by conductive hearing loss, were reduced in amplitude and sensitivity across all frequencies in DS mice. The middle ear space in DS mice appeared normal with no evidence of infection. MicroCT structural imaging of DS temporal bones revealed a smaller tympanic membrane diameter, oval window, and middle ear space and localized thickening of the bony otic capsule, but no gross abnormalities of the middle ear ossicles. Histological analysis of the cochlear and vestibular sensory epithelium revealed a normal density of cochlear and vestibular hair cells; however, the cochlear basal membrane was approximately 0.6 mm shorter in DS than WT mice so that the total number of hair cells was greater in WT than DS mice. In DS mice, the early and late peaks in the auditory brainstem response (ABR), reflecting neural responses from the cochlear auditory nerve followed by subsequent neural centers in the brainstem, were reduced in amplitude and ABR thresholds were elevated to a similar degree across all frequencies, consistent with a conductive hearing impairment. The latency of the peaks in the ABR waveform were longer in DS than WT mice when compared at the same intensity; however, the latency delays disappeared when the data were compared at the same intensity above thresholds to compensate for the conductive hearing loss. Future studies using wideband tympanometry and absorbance together with detailed histological analysis of the middle ear could illuminate the nature of the conductive hearing impairment in DS mice.

Comparison of the Upper and Lower Extremity and Trunk Muscle Masses between Children with Down Syndrome and Children with Typical Development

PURPOSE

Comparison of not only the upper and lower extremity but also trunk muscle masses measured by means of an ultrasound imaging device between children with Down syndrome (DS) and children with typical development (TD).

METHODS

The study included 35 children with TD (TD group) and 26 children with DS (DS group). The upper and lower extremity and trunk muscle thicknesses were measured using an ultrasound imaging device.

RESULTS

The thicknesses of the rectus abdominis, obliquus externus and internus abdominis, rectus femoris, and short head of the biceps femoris muscles were significantly lower in the DS group than in the TD group. The thicknesses of the other upper and lower extremity and trunk muscles did not differ significantly between the groups.

CONCLUSIONS

The results of this study demonstrated lower masses of trunk flexor and knee extensor and flexor muscles in children with DS compared to those in children with TD.

Growth charts for Mexican children with Down syndrome

We present the results of a prospective, observational, descriptive, cross-sectional study performed on a Mexican population of 1867 children, aged 0-18 years, with Down syndrome (DS), observed between 2013 and 2019. A total of 9968 measurements of height, weight, and head circumference, as well as calculation of body mass index (BMI) were used to create growth charts and tables of percentiles. Growth curves were elaborated using Cole's LMS method. The mean weight and length at birth did not differ by sex: the weight was 2750 g for boys and 2710 g for girls (p > 0.05), and the length was 48.2 cm for boys and 47.9 cm for girls (p > 0.05). The mean final height at 18 years was different by sex: 149.6 cm for boys and 141.2 cm for girls. The average BMI at 18 years was 24.2 kg/m² for boys and 21.9 kg/m² for girls. In a comparison with U.S. growth charts, we find that the Mexican population has lower height and weight. These are the first growth curves for the Mexican population with DS. They can be used by health care providers to optimize preventive care by monitoring children with DS for the early identification of factors that affect individual growth.

The best tool for the assessment of developmental disorders in children with down syndrome: comparison of standard and specialized growth charts - cross sectional study

Down Syndrome (DS) is a chromosomal abnormality associated with a spectrum of cognitive and physical disabilities. Children with DS are exposed to both lower and excess body weight and follow distinct growth-curve patterns that deviate significantly from those of children without chromosomal defects. Anthropometric parameters are assessed in the pediatric population with the use of growth charts. The study is based on data from 411 children and adults with DS from Poland. Detailed information concerning children and online survey results were also analyzed. Centiles and standard deviation scores (SDS) of obtained anthropometric parameters were aligned with the data using the LMS method. The study aims to identify which type of growth chart (standard vs specialized) is a leading tool for earlier detection of developmental disorders in DS. The results obtained in the two types of growth charts differed. The advantage of the specialized growth charts over the standard ones cannot be unequivocally determined. Only the combination of both tools allows to detect the development disorders early in the broadest possible way.

Growth in girls with Turner syndrome

Turner syndrome (TS) is a chromosomal disorder affecting females characterized by short stature and gonadal dysgenesis. Untreated girls with TS reportedly are approximately 20-cm shorter than normal girls within their respective populations. The growth patterns of girls with TS also differ from those of the general population. They are born a little smaller than the normal population possibly due to a mild developmental delay in the uterus. After birth, their growth velocity declines sharply until 2 years of age, then continues to decline gradually until the pubertal age of normal children and then drops drastically around the pubertal period of normal children because of the lack of a pubertal spurt. After puberty, their growth velocity increases a little because of the lack of epiphyseal closure. A secular trend in height growth has been observed in girls with TS so growth in excess of the secular trend should be used wherever available in evaluating the growth in these girls. Growth hormone (GH) has been used to accelerate growth and is known to increase adult height. Estrogen replacement treatment is also necessary for most girls with TS because of hypergonadotropic hypogonadism. Therefore, both GH therapy and estrogen replacement treatment are essential in girls with TS. An optimal treatment should be determined considering both GH treatment and age-appropriate induction of puberty. In this review, we discuss the growth in girls with TS, including overall growth, pubertal growth, the secular trend, growth-promoting treatment, and sex hormone replacement treatment.

Is the estimated glomerular filtration rate formula useful for evaluating the renal function of Down syndrome?

BACKGROUND

Children with Down syndrome (DS) have different growth rates compared with normal children. The present study examined the reliability of a general formula, Uemura's formula, utilized in normal Japanese children to estimate renal function (estimated glomerular filtration rate - eGFR) in children with DS.

METHODS

This study included 758 children aged 2-18 years with DS who visited our medical center. Patients with congenital heart disease, or congenital anomalies of the kidney or urinary tract detected via abdominal ultrasonography, chronic glomerulonephritis, and vesicoureteral reflux, etc., were excluded. Height and serum creatinine data gathered from 2421 examinations of 379 children with DS (224 boys and 155 girls) were used to evaluate Uemura's formula.

RESULTS

The mean eGFR was lower in children with DS than in children without DS. Stage II chronic kidney disease was indicated in 44.6% of examinations and stage III in 0.8%. The association of eGFR with age differed between sexes. Boys with DS showed a significant but weak negative correlation between eGFR and age (r = -0.273, P < 0.001), whereas girls with DS showed a significant but very weak negative correlation (r = -0.111, P < 0.001).

CONCLUSIONS

A new eGFR formula that takes into account specific growth rates and puberty is needed for children with DS because general renal function evaluation formulas are inappropriate for these patients.

The Test-Retest Reliability of the Bruininks-Oseretsky Test of Motor Proficiency-Short Form in Youth with Down Syndrome-A Pilot Study

Background: It is unclear whether assessments of motor proficiency are reliable for individuals with Down syndrome. The purpose of the study was to evaluate the test–retest reliability of the Bruininks–Oseretsky Test of Motor Proficiency-Short Form (BOT-2 SF) in youth with Down syndrome. Methods: Ten youth (ages 13.1–20.7 years) with Down syndrome completed the BOT-2 SF (14 items) plus a standing long jump on two separate occasions. Intraclass correlation coefficients (ICC), 95% confidence intervals (CIs), and standard error of measurement (SEM) were calculated to determine the test–retest reliability of the BOT-2 SF and the standing long jump. Results: The test–retest reliability of the BOT-2 SF overall scores and percentile rankings were considered excellent. The test–retest reliability of each of the subtests varied with classifications of poor (n = 5), fair to good (n = 6), and excellent (n = 4). Conclusion: Current evidence suggests that children with Down syndrome have reduced motor skills. However, there appears to be a lack of assessment tools that reliably evaluate the motor skills of this population. The results from this investigation suggest that the BOT-2-SF provides “excellent reliability” (≥0.75) to assess the motor skills in youth with Down syndrome.

Growth Patterns of Thai Children with Down Syndrome from Birth to 5 Years

Specific growth charts for children with Down syndrome (DS) have been developed in several countries, but not in Thailand. This pilot study aims to develop growth patterns for Thai children with DS, which will help clinicians to improve assessment and monitoring of the growth patterns for these children. A retrospective review of 80 children with DS who received care at Thammasat University Hospital between 2014 and 2018 was conducted. A total of 1,681 length/height and weight measurements were collected. Four sex-specific growth patterns of length/height and weight were generated with the fifth, 50th, and 95th percentile. The children with DS were lower in weight and shorter than general Thai children and children with DS in other countries. Therefore, each country should develop individual DS growth charts.

Altered sucking dynamics in a breastfed infant with Down syndrome: a case report

BACKGROUND

The health and developmental advantages of human milk and breastfeeding are particularly important for infants with Down syndrome. However, they typically have shorter breastfeeding duration due to sucking issues that are not well understood. This case report describes serial measures of milk transfer volumes, sucking dynamics and tongue movement in a breastfeeding infant with Down syndrome. Management of maternal milk production enabled feeding of only breast milk until maturation of breastfeeding skills and the achievement of full breastfeeding by 6 months.

CASE PRESENTATION

The mother of a term infant with Down syndrome and no associated health complications presented with concerns regarding adequacy of milk removal at the breast and low milk supply. We monitored sucking dynamics during breastfeeding by measuring intraoral vacuum strength, nutritive and non-nutritive suck rates and burst durations, and tongue movement using submental ultrasound. Breastfeeds were monitored at 4, 10, 14, 19 and 24 weeks, and maternal 24 h milk production was measured at 4, 10 and 24 weeks postpartum. We observed a weaker suck strength and shorter nutritive suck duration, and atypical tongue movement up to 19 weeks, with low milk transfer volumes. Regular breast expression was effective in increasing maternal milk production, providing expressed milk for all complementary feeds. Full breastfeeding was achieved by 6 months when reference sucking values were observed.

CONCLUSIONS

This case report illustrates that infants with Down syndrome may have low intraoral vacuum and limited nutritive sucking that persists for several months, likely due to delayed oro-motor development. In the absence of effective sucking human milk feeding can continue when milk production is stimulated with frequent and adequate breast expression. It is possible for infants with Down syndrome and no associated health complications to eventually establish full breastfeeding. Mothers that wish to breastfeed their infant with Down syndrome require anticipatory guidance and continuing lactation and family support.

Multiorgan involvement and management in children with Down syndrome

AIM

To review multiorgan involvement and management in children with Down syndrome (DS).

METHODS

A literature review of articles from 1980 to 2019 using the MEDLINE interface of PubMed was performed using the following search terms- [Down syndrome] or [Trisomy 21] AND [Cardiology] or [Respiratory] or [neurodevelopment] or [epilepsy] or [musculoskeletal] or [immune system] or [haematological] or [endocrine] or [gastrointestinal] or [ophthalmological] or [Ear Nose Throat] or [dermatology] or [renal].

RESULTS

Congenital heart disease particularly septal defects occur in over 60% of infants with DS and 5%-34% of infants develop persistent pulmonary hypertension of the newborn irrespective of a diagnosis of congenital heart disease. Early recognition and management of aspiration, obstructive sleep apnoea and recurrent lower respiratory tract infections (LRTI) could reduce risk of developing pulmonary hypertension in later childhood. Children with DS have an increased risk of autistic spectrum disorder, attention deficit disorder and epilepsy particularly infantile spasms, which are associated with poor neurodevelopmental outcomes. Congenital anomalies of the gastrointestinal and renal system as well as autoimmune diseases, coeliac disease, arthropathy, thyroid dysfunction fold diabetes mellitus and dermatological conditions are more common. Hearing and visual anomalies are also well recognised association with DS (Table 1).

CONCLUSION

Children with DS are at an increased risk of multiorgan comorbidities. Organ-specific health surveillance may provide holistic care for the children and families with DS throughout childhood.

World Health Organization's Growth Reference Overestimates the Prevalence of Severe Malnutrition in Children with Sickle Cell Anemia in Africa

Anthropometric indices are widely used to assess the health and nutritional status of children. We tested the hypothesis that the 2007 World Health Organization (WHO) reference for assessment of malnutrition in children with sickle cell anemia (SCA) overestimates the prevalence of severe malnutrition when compared to a previously constructed SCA-specific reference. We applied the WHO and SCA-specific references to children with SCA aged 5–12 years living in northern Nigeria (Primary Prevention of Stroke in Children with SCA in sub-Saharan Africa (SPRING) trial) to determine the difference in prevalence of severe malnutrition defined as body mass index (BMI) Z-score <−3 and whether severe malnutrition was associated with lower mean hemoglobin levels or abnormal transcranial Doppler measurements (>200 cm/s). A total of 799 children were included in the final analysis (median age 8.2 years (interquartile range (IQR) 6.4–10.4)). The application of the WHO reference resulted in lower mean BMI than the SCA-specific reference (−2.3 versus −1.2; p < 0.001, respectively). The use of the WHO reference when compared to the SCA-specific reference population also resulted in a higher prevalence of severe malnutrition (28.6% vs. 6.4%; p < 0.001). The WHO reference significantly overestimates the prevalence of severe malnutrition in children with SCA when compared to an SCA-specific reference. Regardless of the reference population, severe malnutrition was not associated with lower mean hemoglobin levels or abnormal transcranial Doppler (TCD) measurements.

The value of anthropometric indices for childhood obesity in Japan

Context: Childhood obesity is one of the most serious public health problems. The simplest method for the identification of adiposity in children involves measuring height and weight because these metrics are easy to obtain and are not greatly affected by observers. Objective: Body mass index (BMI) has been widely used as a surrogate marker of childhood obesity, particularly after the International Obesity Task Force recommended that BMI is appropriate for the determination of childhood obesity. However, in Japan, the percentage of overweight (POW) is more widely used for evaluating childhood obesity. Methods: This review discusses and summarises the situation in Japan regarding the use of various anthropometric indices for assessing childhood obesity, focusing on POW and BMI and including the situation with disease-specific indices. Results: There are two main reasons why POW is widely used in Japan instead of BMI. One reason is that the Japan Society for the Study of Obesity recommended that POW should be used for evaluating childhood obesity. The other reason is that BMI cut-off values for childhood obesity have not been determined in Japan. Conclusion: Individuals involved in child healthcare in Japan should keep in mind both the merits and drawbacks of various anthropometric indices.

Growth curves for French people with Down syndrome from birth to 20 years of age

We present new and complete growth charts for 2,598 healthy French children and adolescents with Down syndrome (DS) from 0 to 20 years old, obtained with highly reliable statistical methods. This study is retrospective and addresses data collected over a period of 12 years, monocentric and with a satisfactory representation of the population nationwide. Final occipito-frontal circumference (OFC) is at the fifth percentile compared to WHO charts, with a drop between 12 and 18 months. Final height is at the first percentile compared to WHO charts for girls and boys with two periods of reduced growth velocity: before 36 months and around puberty. We observed no pubertal growth peak for girls. For boys, pubertal growth peak showed to happen earlier and to be less significant than in the general population. When compared to a previous French study with people affected with DS, pubertal growth acceleration begins at a later age for girls and boys; girls in our study are taller at age 15 (+5 cm), but there is no difference for boys at this age. Overweight is more frequent compared to the typical French population. Mean body mass index (BMI) rises rapidly above the 75th percentile of typical French children as early as age 4, with an earlier age for precocious adiposity rebound. The second period for rapid increase of BMI is around 14 years old. When compared to a previous French study with DS, we did not observe any BMI increase, at least up to the age of 14.

Sleep and sleep disordered breathing in children with down syndrome: Effects on behaviour, neurocognition and the cardiovascular system

Down syndrome (DS), the most common human chromosomal malformation, has an estimated annual incidence of one in 1000 live births worldwide. Sleep problems are common in children with DS, reported by parents in up to 65% of school-aged children, significantly higher rates than in typically developing (TD) children. Problems include difficulty in sleep initiation and maintenance together with obstructive sleep apnoea (OSA) which affects up to over 90%, of DS children compared with 1-5% in the general paediatric population. Any sleep problem has the potential to exert significant negative effects on daytime behaviour, learning and quality of life in TD children and there is now a growing body of evidence that children with DS are similarly affected. In addition to adverse effects on daytime functioning, OSA has adverse effects on the cardiovascular system and this is a particularly significant issue given the high rates of hypertension and premature cardiac disease in people with DS. This review discusses the effects of sleep problems and OSA on daytime functioning and cardiovascular function in children with DS and evidence of the effectiveness of treatment in improving outcomes and quality of life for these children.

The prevalence of obesity in children and young people with Down syndrome

BACKGROUND

Overweight and obesity is a growing concern among individuals with intellectual disabilities; however, little is known about the prevalence among children and youth with Down syndrome (CYDS). The purpose of this study was to determine the prevalence of overweight/obesity among CYDS in South West Ireland.

METHODS

This cross-sectional study measured height and weight of 61 CYDS aged 4-16 years. Body mass index (BMI) was calculated and percentage body fat (PBF) was measured using bio-electrical impendence analysis (BIA).

RESULTS

Using the International Obesity Task Force BMI cut-offs, 51.6% of males and 40% of females were overweight/obese compared to 32% and 14.8%, respectively, using PBF. The mean PBF for males was 18.76 versus females 22.38 (p < .05). There is a higher prevalence of overweight/obesity, particularly in males, compared to the general population of children.

CONCLUSIONS

The difference in estimation of overweight/obesity between BMI and BIA has implications for research and clinical practice.

Development of disease-specific growth charts in Turner syndrome and Noonan syndrome

Many congenital diseases are associated with growth failure, and patients with these diseases have specific growth patterns. As the growth patterns of affected individuals differ from those of normal populations, it is challenging to detect additional conditions that can influence growth using standard growth charts. Disease-specific growth charts are thus very useful tools and can be helpful for understanding the growth pattern and pathogenesis of congenital diseases. In addition, disease-specific growth charts allow doctors to detect deviations from the usual growth patterns for early diagnosis of an additional condition and can be used to evaluate the effects of growth-promoting treatment for patients. When developing these charts, factors that can affect the reliability of the charts should be considered. These factors include the definition of the disease with growth failure, selection bias in the measurements used to develop the charts, secular trends of the subjects, the numbers of subjects of varying ages and ethnicities, and the statistical method used to develop the charts. In this review, we summarize the development of disease-specific growth charts for Japanese individuals with Turner syndrome and Noonan syndrome and evaluate the efforts to collect unbiased measurements of subjects with these diseases. These charts were the only available disease-specific growth charts of Turner syndrome and Noonan syndrome for Asian populations and were developed using a Japanese population. Therefore, when these charts are adopted for Asian populations other than Japanese, different growth patterns should be considered.

Growth charts for Brazilian children with Down syndrome: Birth to 20 years of age

BACKGROUND

The growth of youth with Down syndrome (DS) differs from that of youth without DS, and growth charts specific to DS have been developed. However, little is known about the growth of Brazilian youth with DS. The objective of this study was to construct growth charts for Brazilian youth with DS and compare the growth data with the Child Growth Standards of the World Health Organization (WHO) and charts for children with DS from other studies.

METHODS

Mixed longitudinal and cross-sectional data were collected at University of Campinas, 48 specialized centers for people with intellectual disabilities, and two foundations for people with DS between 2012 and 2015. A total of 10,516 growth measurements from birth to 20 years of age were available from 938 youth with DS (53.7% boys) born between 1980 and 2013. The Lambda Mu Sigma method was applied to construct the curves using generalized additive models for location, scale, and shape.

RESULTS

Length/height-for-age, weight-for-age, and head circumference-for-age percentile curves were generated for Brazilian boys and girls from birth to 20 years of age. Differences in growth of Brazilian youth ranged from -0.8 to -3.2 z-scores compared to WHO standards, and -1.9 to +1.3 compared to children with DS in other studies.

CONCLUSIONS

These specific growth charts may guide clinicians and families in monitoring the growth of Brazilian children and adolescents with DS.

An exploratory study of the association between physical activity, cardiovascular fitness and body size in children with Down syndrome

OBJECTIVE

To explore the association between physical activity, cardiovascular fitness and body size among children with Down syndrome.

METHOD

Physical activity, cardiovascular fitness and body size were measured by accelerometry, maximal fitness test and anthropometric measurements (BMI, waist circumference), respectively.

RESULTS

Fourteen children with Down syndrome (8 boys, 6 girls; mean age 12.9 years) participated. There was no significant correlation between physical activity and cardiovascular fitness or physical activity and body size. Children with Down syndrome who were fitter, had lower BMIs (r = -0.77, 95% confidence interval (CI) -0.41 to -0.93) and smaller waist circumference (r = -0.75, 95% CI -0.36 to -0.92).

CONCLUSION

Preliminary evidence suggests physical activity may not be associated with either body size or fitness in children with Down syndrome. Body size appears to be inversely related to fitness in children with Down syndrome.

Body composition estimation using skinfolds in children with and without health conditions affecting growth and body composition

BACKGROUND

Body composition prediction equations using skinfolds are useful alternatives to advanced techniques, but their utility across diverse paediatric populations is unknown.

AIM

To evaluate published and new prediction equations across diverse samples of children with health conditions affecting growth and body composition.

SUBJECTS AND METHODS

Anthropometric and dual-energy X-ray absorptiometry (DXA) body composition measures were obtained in children with Down syndrome (n = 59), Crohn disease (n = 128), steroid-sensitive nephrotic syndrome (n = 67) and a healthy reference group (n = 835). Published body composition equations were evaluated. New equations were developed for ages 3-21 years using the healthy reference sample and validated in other groups and national survey data.

RESULTS

Fat mass (FM), fat-free mass (FFM) and percentage body fat (%BF) from published equations were highly correlated with DXA-derived measures (r = 0.71-0.98), but with poor agreement (mean difference = 2.4 kg, -1.9 kg and 6.3% for FM, FFM and %BF). New equations produced similar correlations (r = 0.85-1.0) with improved agreement for the reference group (0.2 kg, 0.4 kg and 0.0% for FM, FFM and %BF, respectively) and in sub-groups.

CONCLUSIONS

New body composition prediction equations show excellent agreement with DXA and improve body composition estimation in healthy children and those with selected conditions affecting growth.

Growth references for Japanese individuals with Noonan syndrome

BACKGROUND

Noonan syndrome (NS) is a clinically and genetically heterogeneous syndrome characterized by distinctive facial features, short stature, congenital heart diseases, and other comorbidities. NS-specific growth charts are essential for NS care, but currently no such charts are available for Asian populations.

METHODS

We conducted a nationwide survey by collaborating with three academic societies in Japan. We obtained the data of 356 clinically diagnosed NS subjects from 20 hospitals. The Lambda-Mu-Sigma method was used for establishing growth charts.

RESULTS

A total of 308 subjects (males: 159 and females: 149) were analyzed after excluding 48 subjects because of missing auxological data (26 subjects), presence of complications affecting growth (5 subjects), and extreme longitudinal growth aberrations which lay more than three standard deviation scores from the mean in this population (17 subjects). Genetic analyses were performed in 150 patients (48.7%); 103 (68.7%) were reported to have some abnormalities in the known causative genes. Cardiovascular diseases were found in 256 patients (83.1%). The NS-specific height, weight, and BMI charts were constructed with 3,249 mixed longitudinal and cross-sectional measurements.

CONCLUSION

Growth standards for Japanese individuals with NS were established. These charts are expected to be used in various clinical settings.

Down Syndrome: Gestational Age-Related Neonatal Anthropometrics for Germany

BACKGROUND

Neonates with Down syndrome (DS) weigh less, are smaller and have increased first-year mortality, especially if born small for gestational age (GA). DS-specific GA-related neonatal anthropometrics for Germany are lacking.

OBJECTIVES

To construct reference tables and centile curves for birth weight (g), crown-heel length (cm) and head circumference (cm) by sex and GA for German DS neonates.

METHODS

Retrospective anthropometric data from live-born singleton DS neonates born in Germany from January 1966 to June 2010 were collected using standardized questionnaires and patient records. Reference tables were created based on means and standard deviations. The 3rd, 10th, 25th, 50th, 75th, 90th and 97th centile curves were constructed and smoothed using running medians and Cole's LMS method.

RESULTS

Anthropometric measurements were obtained for 1,304 DS neonates [males/females: 713/591 (54.7%/45.3%)]. Reference tables and centile charts were constructed from 3,542 (males/females: 1,932/1,610) observations for GA 32-41 weeks. Compared with general-population newborns, prematurity was increased (21.1 vs. 6.3%) at GA 32-36 weeks. Term-born (GA 40 weeks) male and female DS neonates were 352.5 and 223.5 g lighter and 1.5 and 1.4 cm smaller than general-population neonates, and head circumference was also 1.4 and 1.5 cm smaller, respectively.

CONCLUSION

This is the first study to report GA-related, sex-specific reference tables and centile charts of birth weight, length and head circumference for DS neonates born in Germany. Compared with the general German population, DS newborns are more frequently born prematurely, weigh less, are smaller and have a smaller head circumference at birth.

Cerebrovascular contributions to aging and Alzheimer's disease in Down syndrome

Down syndrome (DS) is a common cause of intellectual disability and is also associated with early age of onset of Alzheimer's disease (AD). Due to an extra copy of chromosome 21, most adults over 40years old with DS have beta-amyloid plaques as a result of overexpression of the amyloid precursor protein. Cerebrovascular pathology may also be a significant contributor to neuropathology observed in the brains of adults with DS. This review describes the features of cardiovascular dysfunction and cerebrovascular pathology in DS that may be modifiable risk factors and thus targets for interventions. We will describe cerebrovascular pathology, the role of co-morbidities, imaging studies indicating vascular pathology and the possible consequences. It is clear that our understanding of aging and AD in people with DS will benefit from further studies to determine the role that cerebrovascular dysfunction contributes to cognitive health. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock.

Growth Charts for Children With Down Syndrome in the United States

BACKGROUND AND OBJECTIVES

Children with Down syndrome (DS) have lower birth weights and grow more slowly than children without DS. Advances in and increased access to medical care have improved the health and well-being of individuals with DS; however, it is unknown whether their growth has also improved. Our objective was to develop new growth charts for children with DS and compare them to older charts from the United States and more contemporary charts from the United Kingdom.

METHODS

The Down Syndrome Growing Up Study (DSGS) enrolled a convenience sample of children with DS up to 20 years of age and followed them longitudinally. Growth parameters were measured by research anthropometrists. Sex-specific growth charts were generated for the age ranges birth to 36 months and 2 to 20 years using the LMS method. Weight-for-length and BMI charts were also generated. Comparisons with other curves were presented graphically.

RESULTS

New DSGS growth charts were developed by using 1520 measurements on 637 participants. DSGS growth charts for children <36 months of age showed marked improvements in weight compared with older US charts. DSGS charts for 2- to 20-year-olds showed that contemporary males are taller than previous charts showed. Generally, the DSGS growth charts are similar to the UK charts.

CONCLUSIONS

The DSGS growth charts can be used as screening tools to assess growth and nutritional status and to provide indications of how growth of an individual child compares with peers of the same age and sex with DS.

Down syndrome birth weight in England and Wales: Implications for clinical practice

The aim of this study was to determine if syndrome‐specific birth weight charts were beneficial for babies with Down syndrome in England and Wales. Birth weights of 8,825 babies with Down syndrome born in England and Wales in 1989–2010 were obtained from the National Down Syndrome Cytogenetic Register. Birth weight centiles for 30–42 weeks gestation by sex were fitted using the LMS method and were compared to those for unaffected babies from the UK‐WHO growth charts. For babies born with Down syndrome the median birth weight from 37 to 42 weeks was 2,970 g (10th–90th centile: 2,115–3,680) for boys and 2930 g (2,100–3,629) for girls, and the modal age of gestation was 38 weeks, 2 weeks earlier than for unaffected babies. At 38 weeks gestation they were only slightly lighter than unaffected babies (159 g for boys and 86 g for girls). However at 40 weeks gestation the shortfall was much greater (304 g and 239 g, respectively). In neonates with Down syndrome there is little evidence of growth restriction before 38 weeks gestation, so up to this age it is appropriate to use the UK‐WHO birth weight charts. Thereafter birth weight is below that of unaffected babies and it should be plotted on the UK Down syndrome growth charts. © 2015 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc.

Screening for hypothyroidism in Down syndrome using the capillary thyroid stimulating hormone method

OBJECTIVES

To analyze data from the Scottish capillary thyroid stimulating hormone (TSH) screening program for hypothyroidism in Down syndrome to identify a threshold for capillary TSH elevation below which low venous free thyroxine (fT4) (<9 pmol/L) and/or frank venous TSH elevation (>10 mU/L) range is unlikely.

STUDY DESIGN

Review of proformas prospectively submitted on all children with Down syndrome referred via the screening program between 2003 and 2013.

RESULTS

Ninety-nine patients with Down syndrome (50 females, 49 males) were identified, 76 school-age (≥ 5 years) and 23 preschool (<5 years), mean (range) age at referral 9.4 (0.9-18.1) years. Pearson correlation between capillary TSH and venous TSH was 0.814; between capillary TSH and venous fT4 -0.522 (P = .01). Receiver operator curve analysis showed that capillary TSH values of 4 and 6 mU/L were 95.9% and 73.5% sensitive, 5.8% and 80.8% specific, respectively, in predicting venous TSH >10 mU/L. Fifty-three children had capillary TSH values of 4-5.9 mU/L of whom only one, a boy of 15.8 years, had subnormal venous fT4 (<9 pmol/L), and venous TSH >10 mU/L was found in 13 (4 preschool).

CONCLUSIONS

Venous fT4 is normal in almost all patients with Down syndrome with capillary TSH 4-6 mU/L. We propose an algorithm incorporating rescreening by finger prick after 6 months, rather than venepuncture, in school-aged children with borderline capillary TSH elevation. Further data are needed before this approach can be recommended for preschool children.

Factors associated with growth and blood pressure patterns in children with sickle cell anemia: Silent Cerebral Infarct Multi-Center Clinical Trial cohort

Individuals with sickle cell anemia (SCA) exhibit delayed growth trajectories and lower blood pressure (BP) measurements than individuals without SCA. We evaluated factors associated with height, weight, and BP and established reference growth curves and BP tables using data from the Silent Cerebral Infarct Multi-Center Clinical (SIT) Trial (NCT00072761). Quantile regression models were used to determine the percentiles of growth and BP measurements. Multivariable quantile regression was used to test associations of baseline variables with height, weight, and BP measurements. Height and weight measurements were collected from a total of 949 participants with median age of 10.5 years [Interquartile range (IQR) 8.2-12.9] and median follow-up time of 3.2 years (IQR 1.8-4.7, range 0-12.9). Serial BP measurements were collected from a total of 944 and 943 participants, respectively, with median age of 10.6 years (IQR = 8.3-12.9 years), and median follow-up time of 3.3 years (IQR = 1.7-4.8). Multivariable quantile regression analysis revealed that higher hemoglobin measurements at baseline were associated with greater height (P < 0.001), weight (P = 0.000), systolic BP (P < 0.001), and diastolic BP (P = 0.003) measurements. We now provide new reference values for height, weight, and BP measurements that are now readily available for medical management.

Disease-specific growth charts for Korean infants with Prader-Willi syndrome

Patients with Prader-Willi syndrome (PWS) present with short stature and obesity. The growth pattern of children with PWS is different from that of the healthy population. Therefore, it is not appropriate to use normal growth charts to evaluate the growth status of children with PWS. We aimed to develop disease-specific growth charts for height and weight for nongrowth hormone-treated Korean infants with PWS aged between 0 and 36 months and to use these growth charts for the evaluation and management of infants with PWS. We conducted a retrospective review of the medical records of 122 infants with genetically confirmed PWS. Data on the patients' height and weight measurements before they underwent growth hormone treatment were recorded. Disease-specific growth charts were generated and the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th centiles were calculated using the LMS (refers to λ, μ, and σ, respectively) smoothing procedure for height and weight. The disease-specific growth charts for Korean infants with PWS can be used when examining infants with PWS and when evaluating their growth at later stages for comparison purposes. They are also useful for monitoring growth patterns, nutritional assessments, and recording responses to growth hormone treatment.

National growth charts for United Arab Emirates children with Down syndrome from birth to 15 years of age

Background

Specific centile growth charts for children with Down syndrome (DS) have been produced in many countries and are known to differ from those of normal children. Since growth assessment depends on the growth pattern characteristic for these conditions, disorder-specific charts are desirable for various ethnic groups.

Aims

To provide cross-sectional weight, height, and head circumference (HC) references for healthy United Arab Emirates (UAE) children with DS.

Methods

A retrospective and cross-sectional growth study of Emirati children with DS, aged 0 to 18 years old, was conducted. Height, weight, and HC were measured in each child. Cole’s LMS statistical method was applied to estimate age-specific percentiles, and measurements were compared to UAE reference values for normal children.

Results

Incidence of DS in the UAE population is 1 in 374 live births (267 in 10 000 live births). We analyzed 1263 growth examinations of 182 children with DS born between 1994 and 2012. The male-to-female ratio was 1.6:1. Height, weight, and HC centile charts were constructed for ages 0 to 13 years. The prevalence of overweight and obesity in DS children aged 10 to 13 years of age was 32% and 19%, respectively. The DS children were significantly shorter and heavier than normal children in the UAE.

Conclusions

Weight, height, and HC growth charts were created for children with DS. These can be used as a reference standard for the UAE children with DS. Overweight and obesity are quite common in DS children ≥10 years of age, as DS children tend to be shorter and heavier than non-DS children.

Growth charts for Chinese Down syndrome children from birth to 14 years

OBJECTIVE

To establish Down syndrome (DS)-specific growth charts for Hong Kong Chinese children.

DESIGN AND SETTING

Growth data were collected from (1) members of the Hong Kong Down Syndrome Association (cross-sectional); (2) DS children attending special schools or living in residential homes (cross-sectional); and (3) the paediatric departments of seven public hospitals (retrospective).

PATIENTS

425 DS children (57% males and 43% females) born in 1977-2000, yielding 4987 observations.

MAIN OUTCOME MEASURES

The LMS method was used to construct reference centile curves of weight, height, body mass index (BMI) from birth until 14 years and head circumference for the first 4 years.

RESULTS

The median birth length was 49.8 cm and height at age 14 was 146.7 cm for DS boys. Corresponding figures for DS girls were 49.5 and 142.1 cm. The median birth weight was 3.0 kg for DS boys and 2.9 kg for DS girls. At age 14, 26% DS boys (BMI >22.6 kg/m(2)) and 12% DS girls (BMI >23.3 kg/m(2)) were overweight. The median head circumference at birth was 32.8 cm for boys and 32.0 cm for girls.

CONCLUSIONS

Chinese DS children had a shorter stature, lower weight and tendency to be overweight than local non-DS children. Their growth patterns differed from those of Chinese DS children in Taiwan, and DS children in the USA and Sweden. Growth retardation was most salient during the first year of life.

Weight-for-age distribution and case-mix adjusted outcomes of 14,307 paediatric intensive care admissions

Aims

To determine whether the paediatric intensive care (PIC) population weight distribution differs from the UK reference population and whether weight-for-age at admission is an independent risk factor for mortality.

Methods

Admission weight-for-age standard deviation scores (SDS) were calculated for all PIC admissions (March 2003–December 2011) to Great Ormond Street Hospital: this is the number of standard deviations (SD) between a child’s weight and the UK mean weight-for-age. Categorised into nine SDS groups, standardised mortality ratios (SMR) and logistic regression were used to assess the relationship between weight-for-age at admission and risk-adjusted mortality.

Results

Out of 12,458 admissions, mean weight-for-age was 1.04 SD below the UK reference population mean (p < 0.0001). Based on 942 deaths, risk-adjusted mortality was lowest in those with mild-to-moderately raised weight-for-age (SDS 0.5–2.5) and highest in children with extreme under- or overweight (SDS < −3.5 and SDS > +3.5). Logistic regression indicated that age, gender, ethnicity and weight-for-age are independent risk factors for mortality. South Asian and ‘other’ ethnicities had significantly increased risk of death compared to children of white and black ethnic origin.

Conclusion

The PIC population mean weight-for-age is significantly lower than the UK reference mean. The extremes of weight-for-age are over-represented, especially underweight. Weight-for-age at admission is an independent risk factor for mortality. A U-shaped association between weight and risk-adjusted mortality exists, with the lowest risk of death in children who are mild-to-moderately overweight. Future studies should determine the impact of malnutrition on risk-adjusted mortality and investigate the aetiology of risk disparities with ethnicity.

Electronic supplementary material

The online version of this article (doi:10.1007/s00134-014-3381-x) contains supplementary material, which is available to authorized users.

Diagnosis and management of Down syndrome

Down syndrome is the commonest chromosomal disorder causing mild to moderate intellectual disability, yet it is one of the neglected disorder amongst practicing physicians. Children with Down syndrome when intervened early by speech therapy, physiotherapy and occupational therapy and given proper medical attention for different health issues, can have a better long term outcome as compared to other genetic causes of intellectual disability. This paper would help the general practitioners to identify children with Down syndrome and to manage the common problems associated with this condition.

Methodologies to assess paediatric adiposity

INTRODUCTION

Childhood obesity is associated with increased risk of adult obesity, cardiovascular disease, diabetes and cancer. Appropriate techniques for assessment of childhood adiposity are required to identify children at risk. The aim of this review was to examine core clinical measurements and more technical tools to assess paediatric adiposity.

METHODS

The online databases PubMed, CINALH and EMBASE were searched and the abstracts identified were reviewed to determine appropriate studies. Their reference lists were also searched to identify further eligible studies. Publications were included if they described childhood measurement techniques or involved validation.

RESULTS AND DISCUSSION

There are many body composition assessment tools available, none of which are direct. Each technique has limitations and a combination of methods may be used. The main clinical techniques are weight, height, body mass index (BMI) and circumferences which provide sufficient information to enable classification of overweight or obesity when growth centile charts and ratios are employed. Further investigation depends on resources available and examiner skill. Skinfold thicknesses are cost-effective but require technical training and only measure subcutaneous fat. Dual energy X-ray absorptiometry (DEXA), air displacement plethysmography (ADP), magnetic resonance imaging (MRI) and computed tomography (CT) are more costly and intensive, requiring the child to remain still for longer periods. DEXA and ADP are capable of accurately measuring adiposity but are unable to distinguish between fat depots. MRI and CT can distinguish intra-abdominal from subcutaneous adiposity and are considered gold standards, but CT is unsuitable for adiposity measurement in children due to high levels of radiation exposure. Ultrasound is a promising technique capable of measuring intra-abdominal adiposity in children but requires further validation.

CONCLUSION

The core clinical measurements of weight, height, BMI and circumferences are sufficient to enable diagnosis of paediatric overweight and obesity while more technical tools provide further insight.

Growth curves in Down syndrome: implications for clinical practice

Growth curves have been developed for individuals with Down syndrome (DS) in several countries. However, in order to facilitate the preparation of clinical guidelines it is necessary to verify the eligibility of these curves. The search was conducted according to the PRISMA method (Preferred Reporting Items for Systematic reviews and Meta-Analyses). It was conducted between July 2012 and June 2013 in MEDLINE/PubMed and BIREME. The inclusion and exclusion criteria were applied to identify the studies and a total of 16 relevant articles were selected. The aspects analyzed in the articles consisted of sample size, number of observations, age group, anthropometric variables, standard deviation scores (SDS), type of study, collection and analysis of data, participants, inclusion/exclusion criteria and outcomes. The mean, standard deviations (SDs) and percentiles for sex and age were used to develop the curve of weight, height, and head circumference. The individuals with DS presented growth between -0.4 and -4.0 SDS in comparison to healthy controls. The variation in these observations can be explained by genetic differences, secular trends in growth and disease status. Regarding the limitations identified, it was observed that most of the studies did not provide data concerning the number of individuals and observations, mean values and respective SDs by sex and age. In addition, most studies did not use LMS methods to evaluate asymmetry, the median and data variability. In conclusion, the results of this review demonstrated that in order to avoid false diagnoses in children and adolescents with DS new growth curves must be developed.

Bone mass and density in preadolescent boys with and without Down syndrome

Preadolescent boys with Down syndrome at 7-10 years of age have lower bone mass and density in the pelvis than age-matched children without Down syndrome. However, bone mass and density of total body less head and lumbar spine are not different between these two groups.

INTRODUCTION

This study aimed to assess bone mineral content (BMC) and density (BMD) in preadolescent boys with and without Down syndrome (DS) at 7-10 years of age.

METHODS

Eleven preadolescent boys with DS and eleven age-matched children without DS participated in this study. Dual-energy X-ray absorptiometry was used to measure BMC and BMD in whole body and lumbar spine. Both BMC and BMD of total body less head (TBLH) and lumbar spine (vertebrae L2-L4) were compared between the two groups, with and without adjusting for physical characteristics such as bone area, body height, and total lean mass. Two bone mineral apparent density (BMAD) variables were calculated to estimate volumetric BMD in the lumbar spine.

RESULTS

Both BMC and BMD in the pelvis were lower in the DS group, after adjusting for physical characteristics. However, with and without adjusting for physical characteristics, the two groups were not different in BMC and BMD of the arms, legs, and TBLH from the whole body scan and in BMC, BMD, and BMAD of the lumbar spine from the lumbar spine scan.

CONCLUSIONS

These findings indicate that the pelvis may be the first site to show the significant difference in BMC and BMD between preadolescent boys with and without DS. It also suggests that significantly lower BMC and BMD in whole body and lumbar spine, which is usually observed in young adults with DS, may not occur before adolescence.

Is body mass index a useful measure of excess body fatness in adolescents and young adults with Down syndrome?

BACKGROUND

To determine the validity of body mass index (BMI) to identify excess fatness in youth with Down syndrome (DS).

METHODS

Using the Centers for Disease Control and Prevention (CDC) growth reference, we defined overweight (≥ 85th percentile) and obesity (≥ 95th percentile) based on participants' age- and sex-specific BMI z-scores, calculated from measured height and weight. Percentage body fat was measured by dual-energy X-ray absorptiometry. We determined sensitivity, specificity, positive predictive value, negative predictive value and efficiency of BMI percentiles to identify excess adiposity relative to elevated percentage body fat cut-offs developed from the Pediatric Rosetta Body Composition project in 32 youth (20 boys/12 girls), ages 13-21 years with Down syndrome.

RESULTS

For adolescents with Down syndrome using the cut-off points of 95th percentile for BMI (obesity), sensitivity and specificity were 71% and 96% respectively. Positive predictive value was 83% and negative predictive value was 92%. Overall efficiency was 91%. Sensitivity and specificity for BMI cut-offs above the 85th percentile (overweight) were 100% and 60% respectively. The positive predictive value was 41% and negative predictive value was 100%. Overall efficiency was 69%.

CONCLUSION

On the whole, the obesity (≥ 95th percentile) cut-off performs better than the overweight cut-off (85th-94th percentile) in identifying elevated fatness in youth with DS.

Resting energy expenditure and adiposity accretion among children with Down syndrome: a 3-year prospective study

Background

Children with Down syndrome (DS) have a higher prevalence of obesity than other children. Whether this increased risk for obesity is due to a lower resting energy expenditure (REE) is controversial. Our study assessed whether 1) the REE of children with DS adjusted for fat free mass (FFM) was lower than that of sibling controls and 2) the changes in fat mass (FM) over three years were associated with FFM-adjusted baseline REE.

Methods

This study used cross-sectional and prospective cohort designs. Four annual measurement visits were conducted with 28 children with DS and 35 sibling controls aged 3–10y. REE and serum thyroxine (T4) were measured at baseline. Anthropometry, skinfold thicknesses measures, and, in a subsample, dual energy x-ray absorptiometry (DXA) were used at each visit to calculate FM.

Results

Children with DS had significantly lower REE adjusted for FFM (−78 kcal/day, 95% CI: −133 to −27, p=0.003). The difference remained significant after adjustment for FM, sex, and African ancestry (−49 kcal/day, 95% CI: −94 to −4, p=0.03). In the longitudinal analysis, the baseline REE adjusted for baseline FFM was not predictive of FM accretion over time (p=0.8).

Conclusion

Children with DS have lower REE than sibling controls, but REE was not associated with changes in FM over time. The results suggest that the lower REE of children with DS does not explain their increased risk for obesity.

Bioelectrical impedance for measuring percentage body fat in young persons with Down syndrome: validation with dual-energy absorptiometry

AIM

Children with Down syndrome have an increased prevalence of obesity, although there is little work describing body composition in this population. The aims of this study were to accurately measure body fat in children with Down syndrome and to identify which existing algorithm best predicts percentage body fat in this population.

METHODS

Seventy children with Down syndrome had anthropometric, bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) data collected to calculate percentage body fat (PBF). Pearson correlations were carried out to assess the relationships of various methods for measuring body fat and Bland-Altman plots to assess systematic error.

RESULTS

Mean PBF was 30.5% for girls and 22.5% for boys. A total of 38% of girls and 23% of boys were obese according to international criteria. PBF as determined by DXA correlated well with PBF by BIA in both girls and boys (r = 0.91 and 0.89, respectively, p < 0.001).

CONCLUSION

There are high rates of obesity in children with Down syndrome. BIA can be used to accurately determine adiposity in this population. We recommend the use of the Schaeffer algorithm for calculation of PBF in children with Down syndrome.