Body composition in Prader-Willi syndrome compared with nonsyndromal obesity: Relationship to physical activity and growth hormone function

Lean Body Mass in Boys With Prader-Willi Syndrome Increases Normally During Spontaneous and Induced Puberty

CONTEXT

Prader-Labhart-Willi syndrome (PWS) is a rare genetic disorder characterized by intellectual disability, behavioural problems, and hypothalamic dysfunction combined with specific dysmorphisms. In PWS, growth hormone treatment is given primarily to improve body composition, yet lean body mass (LBM) does not normalize. Male hypogonadism is frequent in PWS and becomes evident during puberty. While LBM increases in normal boys during puberty, it is not known whether LBM and muscle mass concomitantly increase in PWS during spontaneous or induced puberty.

OBJECTIVE

To describe the peripubertal increment in muscle mass in boys with PWS undergoing growth hormone treatment.

DESIGN

Single-center, retrospective descriptive study, using data from 4 years before until 4 years after onset of puberty.

SETTING

Primary referral centre for PWS.

PATIENTS

Thirteen boys diagnosed with genetically proven PWS. The mean age at onset of puberty was 12.3 years; the mean observation period before (after) onset of puberty was 2.9 (3.1) years.

INTERVENTION

Puberty was induced upon pubertal arrest. All boys received internationally standardized growth hormone treatment.

MAIN OUTCOME MEASURE

Lean mass index (LMI) determined by dual energy X-ray absorptiometry.

RESULTS

LMI increased by 0.28 kg/m2 per year before puberty and by 0.74 kg/m2 per year after the onset of puberty. The time before puberty explained less than 10% of the variation in LMI, whereas the time after puberty onset explained about 25%.

CONCLUSION

Boys with PWS showed a recognizable increment in LMI during both spontaneous and induced puberty compared with the prepubertal phase, which was within the trajectories of normal boys. Therefore, timely testosterone substitution in the absence or at arrest of puberty during growth hormone treatment is important to optimize peak LBM in PWS.

Follow-Up Study of Growth Hormone Therapy in Children with Kabuki Syndrome: Two-Year Treatment Results

INTRODUCTION

Kabuki syndrome (KS) is a genetic disorder with characteristic facial dysmorphisms, short stature, hypertension, and obesity later in life. The aim of this study was to evaluate catch-up growth and cardiovascular markers before and during growth hormone (rhGH) treatment in KS children.

METHODS

This prospective study included 18 children whose KS was genetically established. Each KS subject received rhGH for a period of 2 years. Several measurements were performed before and during treatment: anthropometry, glucose metabolism, lipid profile, markers for endothelial function, and low-grade inflammation.

RESULTS

This study found an increase in delta height standard deviation score (SDS) for the whole group of 1.1 SDS after 2 years of rhGH treatment. Baseline metabolic profiles showed no cardiometabolic abnormalities in these children. Although 4 out of 18 children were obese, there were no signs of the metabolic syndrome. During rhGH treatment, serum low-density lipoprotein cholesterol concentrations decreased significantly (2.16-1.91 mmol/L, p = 0.04). Apolipoprotein B100 concentrations also showed a reduction after 24 months of treatment, but the other lipid and (apo)lipoprotein parameters did not change. While other endothelial function markers were stable, only vascular cell-adhesion molecule-1 concentrations increased (1,084-1,161 pg/mL, p < 0.01) during rhGH therapy. Furthermore, BMI and waist circumference improved during treatment. There were no signs of hypertension.

CONCLUSIONS

At baseline and during rhGH therapy, there were no signs of the metabolic syndrome. This is the first study demonstrating that rhGH treatment in KS children is a safe and effective therapy and that it positively influences linear height without exerting adverse effects on a wide array of cardiovascular risk markers.

Irisin and Secondary Osteoporosis in Humans

Irisin is a peptide secreted by skeletal muscle following exercise that plays an important role in bone metabolism. Numerous experiments in vitro and in mouse models have shown that the administration of recombinant irisin promotes osteogenesis, protects osteocytes from dexamethasone-induced apoptosis, prevents disuse-induced loss of bone and muscle mass, and accelerates fracture healing. Although some aspects still need to be elucidated, such as the dose- and frequency-dependent effects of irisin in cell cultures and mouse models, ample clinical evidence is emerging to support its physiological relevance on bone in humans. A reduction in serum irisin levels, associated with an increased risk of osteoporosis and bone fractures, was observed in postmenopausal women and in both men and women during aging, Recently, cohort studies of subjects with secondary osteoporosis showed that these patients have lower circulating levels of irisin, suggesting that this myokine could be a novel marker to monitor bone quality in this disease. Although there are still few studies, this review discusses the emerging data that are highlighting the involvement of irisin in some diseases that cause secondary osteoporosis.

The genetic background and vitamin D supplementation can affect irisin levels in Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is associated to distinctive clinical symptoms, including obesity, cognitive and behavioral disorders, and bone impairment. Irisin is a myokine that acts on several target organs including brain adipose tissue and bone. The present study was finalized to explore circulating levels of irisin in children and adult PWS patients.

METHODS

Seventy-eight subjects with PWS, 26 children (15 females, mean age 9.48 ± 3.6 years) and 52 adults (30 females, mean age 30.6 ± 10.7) were enrolled. Irisin serum levels were measured in patients and controls. Its levels were related with anthropometric and metabolic parameters, cognitive performance and bone mineral density either in pediatric or adult PWS. Multiple regression analysis was also performed.

RESULTS

Irisin serum levels in PWS patients did not show different compared with controls. A more in-depth analysis showed that both pediatric and adult PWS with DEL15 displayed significantly reduced irisin levels compared to controls. Otherwise, no differences in irisin concentration were found in UPD15 patients with respect to controls. Our study revealed that in pediatric PWS the 25(OH) vitamin-D levels affected irisin serum concentration. Indeed, patients who were not supplemented with vitamin D showed lower irisin levels than controls and patients performing the supplementation. Multiple regression analysis showed that irisin levels in pediatric and adult PWS were predicted by the genetic background and 25(OH)-vitamin D levels, whereas in a group of 29 adult PWS also by intelligent quotient.

CONCLUSION

We demonstrated the possible role of genetic background and vitamin-D supplementation on irisin serum levels in PWS patients.

Physical Activity in Patients with Prader-Willi Syndrome-A Systematic Review of Observational and Interventional Studies

Physical activity (PA) is an important aspect of the management of patients with Prader-Willi syndrome (PWS). However, the day-to-day implementation of PA programs is particularly challenging in these patients. This systematic review aimed (1) to describe habitual PA and sedentary behavior and (2) to assess the effects of PA interventions and to describe their implementation process, in children and adults with PWS. A systematic search of controlled trials, single-group interventions, observational, and qualitative studies published up to December 2020 was performed. Twenty-five studies were included. Habitual PA was found to be lower in patients with PWS compared to controls without obesity or with non-syndromic obesity. Habitual PA was positively associated with lean body mass and bone parameters in children with PWS, and these finding were strengthened by intervention studies reporting an increase in both outcomes after a PA program. PA programs also improved physical function (muscle strength, walking distance, and coordination), without significant effect on weight and fat mass. Attendance to exercise sessions was usually high and no serious adverse effect was reported. In conclusion, supervised PA programs are beneficial for children and adults with PWS. Support should be provided to families to facilitate their implementation in real-life settings.

Myokine levels after resistance exercise in young adults with Prader-Willi syndrome (PWS)

Individuals with PWS require marked caloric restriction and daily exercise to prevent morbid obesity. Lower energy expenditure, hypotonia, decreased muscle mass, and cognitive impairment make exercise challenging for this population. Exercise guidelines include resistance training as an important component. Myokine responses to resistance exercise may mediate beneficial metabolic effects. We aimed to determine if young PWS adults can perform a resistance exercise program and to measure myokine responses in PWS versus age- and BMI-matched controls. Each group included 11 participants (7M/4F). Ages and BMI for PWS and controls were 30.7 ± 4.6 versus 30.1 ± 4.3 years and 28.3 ± 4.3 versus 28.2 ± 4.2 kg/m² , respectively. Glucose, creatine kinase (CK), lactate, and myokines were measured before, after, 30, and 60 min after completing eight resistance exercises. Myokines were assayed using a multiplex myokine panel (Merck Millipore). CK was lower in PWS versus controls (62 ± 16 vs.322 ± 100 U/L, p < .04). Peak lactate was 3.7 ± 0.7 in PWS versus 7.3 ± 0.7 mmol/Lin controls (p < .001). The increase in interleukin-6 was similar in PWS and controls (41 ± 16% and 35 ± 10%, respectively). Pre- and post-exercise levels of the six myokines assayed showed no consistent differences between the PWS and control participants. PWS young adults are capable of performing resistance/strength-building exercise. The lower CK and peak lactate levels in PWS may reflect decreased muscle mass in this population. Further studies are needed to determine optimal exercise regimens and assess the role of myokines incontributing to the metabolic phenotype of PWS.

Physical exercise and Prader-Willi syndrome: A systematic review

OBJECTIVE

The aim of this systematic review was to summarize evidence on the acute responses of individuals with Prader-Willi syndrome (PWS) to physical exercise, and on the effectiveness of long-term exercise interventions to improve the clinical manifestations of this syndrome.

DESIGN/METHODS

Relevant articles were identified in the electronic databases PubMed, Medline, CINAHL and SPORTDiscus (from inception to December 2018). Twenty-two studies including a total of 356 patients with PWS met all inclusion criteria and were included in the review.

RESULTS

Patients with PWS present with a decreased physical performance and impaired cardiorespiratory (maximal oxygen consumption, heart rate recovery after exercise) and hormonal (growth hormone release) responses to exercise. Most long-term exercise interventions have proven to decrease body mass while improving physical performance. Some benefits have also been reported in biochemical (glucose homeostasis, lipid profile) and biomechanical (gait pattern) variables, although there is controversy regarding the effects on body composition. No exercise-related adverse events have been reported in patients with PWS.

CONCLUSION

Physical exercise seems to be safe and effective for improving several phenotypes in PWS, notably physical fitness. However, further research is needed to confirm these results and especially to corroborate whether exercise per se or combined with dietary intervention is an effective coadjuvant treatment for reducing body mass in these patients.

Hypermobility in individuals with Kabuki syndrome: The effect of growth hormone treatment

Kabuki syndrome (KS) is a multiple congenital malformation syndrome which has been described across all ethnic groups. Most KS patients possess two genetic subtypes: KMT2D-associated, autosomal-dominant KS type 1 (KS1; OMIM 147920); and KDM6A-associated, X-linked-dominant KS type 2. Generalized joint hypermobility is one feature of KS, but its exact incidence and pattern is not well described in the literature. As part of our prospective study on the metabolic and growth effect of GH treatment, we assessed children from our Dutch Kabuki cohort who were eligible for growth hormone therapy. We assessed severity and pattern of joint hypermobility, both before and after 24 months of growth hormone replacement therapy. The prevalence of hypermobility was 31% in boys and 14% in girls using the Beighton score and 69% in boys and 57% in girls using the Bulbena score. This varies from the general population where girls are more affected. After 2 years of growth hormone treatment, there was a statistically significant decrease in the presence of joint hypermobility to 6% using the Bulbena score and none with respect to the Beighton score. We hypothesized that this result suggests a direct effect of growth hormone on connective tissue in patients with KS.

The associations between diet and physical activity with body composition and walking a timed distance in adults with Prader-Willi syndrome

Background

Research on aging in Prader–Willi syndrome (PWS) is limited, although people with PWS are living longer. Individuals with PWS present with high fat mass, low lean mass, and low levels of physical activity (PA). Previous reports in children and young adults with PWS show inadequate nutrient intake and body fat percentage indicating obesity. Previous studies in PWS rarely included individuals beyond young adulthood, especially studies conducted in the United States. This study includes adults from 18 to 62 years of age, and includes 19 of the estimated 60 adult individuals with PWS in Oklahoma. Because individuals with PWS are living longer, information must be provided on aging with PWS. This study is a report of the initial data for a planned longitudinal study on aging with PWS.

Objective

Determine associations between body composition, diet, PA, and a timed walk for adults with PWS, and to assess adequacy of dietary intake for those individuals aging with PWS.

Design

This cross-sectional investigation determined dietary habits, PA, and body composition of adults with PWS, and tested associations between these variables.

Results

Participants ranged in age from 18 to 62 years. They had healthier body composition, at 26.8% body fat, than previously reported. Mean body mass index (BMI) was in the overweight range at 26.7. Those who consumed higher amounts of fat (as a percent of total kilocalories) had statistically significant lower body fat percentage, but this may simply reflect that individuals with lower body fat percentages felt freer to consume fat. Mean steps taken per day was 7631.7 steps but only 16% of participants met healthy PA recommendations despite participating in daily structured exercise. All participants’ diets met Dietary Guidelines for macronutrient distribution, but 80% were deficient in calcium, 100% were deficient in dietary vitamin D, and 87% were deficient in fiber. Sample size was small, so it was difficult to reach statistical significance, despite seeing clinical significance.

Conclusions

Recommend working toward healthy PA recommendations for all age groups by decreasing time in sedentary activity. Recommend increasing vitamin A and D fortified dairy products and high-fiber foods, and consider dietary supplementation, especially for calcium, vitamin D, and fiber.

Hormonal, metabolic and skeletal phenotype of Schaaf-Yang syndrome: a comparison to Prader-Willi syndrome

Background

Nonsense and frameshift mutations in the maternally imprinted, paternally expressed gene MAGEL2, located in the Prader-Willi critical region 15q11-15q13, have been reported to cause Schaaf-Yang syndrome (SYS), a genetic disorder that manifests as developmental delay/intellectual disability, hypotonia, feeding difficulties and autism spectrum disorder. Prader-Willi syndrome (PWS) is a genetic disorder characterised by severe infantile hypotonia, hypogonadotrophic hypogonadism, early childhood onset obesity/hyperphagia, developmental delay/intellectual disability and short stature. Scoliosis and growth hormone insufficiency are also prevalent in PWS.

There is extensive documentation of the endocrine and metabolic phenotypes for PWS, but not for SYS. This study served to investigate the hormonal, metabolic and body composition phenotype of SYS and its potential overlap with PWS.

Methods

In nine individuals with SYS (5 female/4 male; aged 5–17 years), we measured serum ghrelin, glucose, insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3, follicle-stimulating hormone, luteinising hormone, thyroid-stimulating hormone, free T4, uric acid and testosterone, and performed a comprehensive lipid panel. Patients also underwent X-ray and dual-energy X-ray absorptiometry analyses to assess for scoliosis and bone mineral density.

Results

Low IGF-1 levels despite normal weight/adequate nutrition were observed in six patients, suggesting growth hormone deficiency similar to PWS. Fasting ghrelin levels were elevated, as seen in individuals with PWS. X-rays revealed scoliosis >10° in three patients, and abnormal bone mineral density in six patients, indicated by Z-scores of below −2 SDs.

Conclusion

This is the first analysis of the hormonal, metabolic and body composition phenotype of SYS. Our findings suggest that there is marked, but not complete overlap between PWS and SYS.

Energy Metabolism Profile in Individuals with Prader-Willi Syndrome and Implications for Clinical Management: A Systematic Review

Prader-Willi syndrome (PWS) is a rare genetic disorder associated with excessive weight gain. Hyperphagia associated with PWS may result in higher energy intake, but alterations in energy expenditure may also contribute to energy imbalance. The purpose of this critical literature review is to determine the presence of alterations in energy expenditure in individuals with PWS. Ten studies that measured total energy expenditure (TEE), resting energy expenditure (REE), sleep energy expenditure (SEE), activity energy expenditure (AEE), and diet induced thermogenesis (DIT) were included in this review. The studies provided evidence that absolute TEE, REE, SEE, and AEE are lower in individuals with PWS than in age-, sex-, and body mass index-matched individuals without the syndrome. Alterations in lean body mass and lower physical activity amounts appear to be responsible for the lower energy expenditure in PWS rather than metabolic differences. Regardless of the underlying mechanism for lower TEE, the estimation of energy requirements with the use of equations derived for the general population would result in weight gain in individuals with PWS. The determination of energy requirements for weight management in individuals with PWS requires a more comprehensive understanding of energy metabolism. Future studies should aim to comprehensively profile all specific components of energy expenditure in individuals with PWS with the use of appropriately matched controls and gold standard methods to measure energy metabolism and body composition. One component of energy expenditure that is yet to be explored in detail in PWS is DIT. A reduced DIT (despite differences in fat free mass), secondary to hormonal dysregulation, may be present in PWS individuals, leading to a reduced overall energy expenditure. Further research exploring DIT in PWS needs to be conducted. Dietary energy recommendations for weight management in PWS have not yet been clearly established.

Review of Prader-Willi syndrome: the endocrine approach

Prader-Willi syndrome (PWS) is a complex genetic disorder with implications on the endocrine and neurologic systems, metabolism, and behavior. Early in life, PWS is characterized by hypotonia and failure to thrive, followed by obesity and hyperphagia. Patients with PWS develop hypothalamic dysfunction which may lead growth hormone deficiency (GHD), hypogonadism, hypothyroidism, adrenal insufficiency, and poor bone mineral density (BMD). In addition to hypothalamic dysfunction, individuals with PWS have increased risk for obesity which may be complicated by metabolic syndrome and type 2 diabetes mellitus (T2DM). In this paper, we will review the current literature pertaining to the endocrine concerns of PWS and current recommendations for screening and management of these conditions.

Treino parental para manejo comportamental de crianças com Síndrome de Prader-Willi: impacto sobre a saúde mental e práticas educativas do cuidador

RESUMO Objetivo: verificamos os indicadores de impacto na saúde mental de cuidadores de um programa de treinamento parental para manejo de crianças e adolescentes com Síndrome de Prader-Willi. Métodos: a amostra foi composta por 5 mães de crianças/adolescentes com Síndrome de Prader-Willi entre 6 a 18 anos. Os instrumentos de coleta de dados foram: a) Questionário para verificação de conhecimentos das mães sobre a síndrome, b) Inventário de Auto-avaliação para Adultos de 18 a 59 anos, c) Inventário de Estilos Parentais/Práticas educativas maternas e paternas; d) Levantamento de dificuldades e preocupações sobre os filhos. O estudo foi realizado em quatro fases: pré-intervenção, intervenção, pós-intervenção e seguimento. Resultados: as mães passaram a adotar práticas parentais educativas baseadas na monitoria positiva, diminuíram as práticas de risco. Conclusão: houve melhora em indicadores de dificuldades emocionais das mães, apreenderam a identificar e manejar fatores que prejudicavam a saúde física, o comportamento e a aprendizagem escolar dos filhos e a necessidade do envolvimento de outros familiares no cuidado do filho.

A Characterization of Movement Skills in Obese Children With and Without Prader-Willi Syndrome

PURPOSE

The aim of this study was twofold: (a) to measure and compare motor proficiency in obese children with Prader-Willi syndrome (OB-PWS) to that in obese children without PWS (OB), and (b) to compare motor proficiency in OB-PWS and OB to normative data.

METHOD

Motor proficiency was measured using the Bruininks-Oseretsky Test of Motor Proficiency-Second Edition-Complete Form, a norm-referenced assessment of motor function. Participants were 18 OB-PWS and 44 OB (8 to 11 years of age). The scores on the 8 subtests and the total motor composite were used to compare OB-PWS and OB. Furthermore, the scores on the 4 motor-area composites were used to compare OB-PWS and OB against normative data.

RESULTS

OB-PWS scored significantly lower than OB across all 8 subtests. OB-PWS also had significantly lower motor proficiency scores on all motor-area composites when compared with the normative sample. OB-PWS most frequently (67%-83%) scored well below average on the gross motor subtests. Although not as high as on the gross motor subtests, this finding also held true for the fine motor subtests with 39% to 45% of OB-PWS scoring well below average.

CONCLUSION

Motor proficiency is very poor in OB-PWS, in particular for gross motor skills. Physical, neurological, and developmental characteristics inherent to the syndrome may explain this low performance.

Association between physical activity and bone in children with Prader-Willi syndrome

BACKGROUND

The aim of the study was to determine if physical activity (PA) is associated with bone health in children with Prader-Willi syndrome (PWS).

METHODS

Participants included 23 children with PWS (age: 11.0±2.0 years). PA, measured by accelerometry, was categorized into light, moderate, vigorous and moderate plus vigorous intensities. Hip, total body minus the head (body), bone mineral content (BMC), bone mineral density (BMD) and BMD z-score (BMDz) were measured by dual X-ray absorptiometry. Separate hierarchical regression models were completed for all bone parameters, PA intensity and select covariates.

RESULTS

Moderate PA and select covariates explained the most variance in hip BMC (84.0%), BMD (61.3%) and BMDz (34.9%; p<0.05 for all). Likewise, for each body parameter, moderate PA and select covariates explained the most variance in body BMC (75.8%), BMD (74.4%) and BMDz (31.8%; p<0.05 for all).

CONCLUSIONS

PA of at least moderate intensity appears important for BMC and BMD in children with PWS.

Prader-Willi Critical Region, a Non-Translated, Imprinted Central Regulator of Bone Mass: Possible Role in Skeletal Abnormalities in Prader-Willi Syndrome

Prader-Willi Syndrome (PWS), a maternally imprinted disorder and leading cause of obesity, is characterised by insatiable appetite, poor muscle development, cognitive impairment, endocrine disturbance, short stature and osteoporosis. A number of causative loci have been located within the imprinted Prader-Willi Critical Region (PWCR), including a set of small non-translated nucleolar RNA's (snoRNA). Recently, micro-deletions in humans identified the snoRNA Snord116 as a critical contributor to the development of PWS exhibiting many of the classical symptoms of PWS. Here we show that loss of the PWCR which includes Snord116 in mice leads to a reduced bone mass phenotype, similar to that observed in humans. Consistent with reduced stature in PWS, PWCR KO mice showed delayed skeletal development, with shorter femurs and vertebrae, reduced bone size and mass in both sexes. The reduction in bone mass in PWCR KO mice was associated with deficiencies in cortical bone volume and cortical mineral apposition rate, with no change in cancellous bone. Importantly, while the length difference was corrected in aged mice, consistent with continued growth in rodents, reduced cortical bone formation was still evident, indicating continued osteoblastic suppression by loss of PWCR expression in skeletally mature mice. Interestingly, deletion of this region included deletion of the exclusively brain expressed Snord116 cluster and resulted in an upregulation in expression of both NPY and POMC mRNA in the arcuate nucleus. Importantly, the selective deletion of the PWCR only in NPY expressing neurons replicated the bone phenotype of PWCR KO mice. Taken together, PWCR deletion in mice, and specifically in NPY neurons, recapitulates the short stature and low BMD and aspects of the hormonal imbalance of PWS individuals. Moreover, it demonstrates for the first time, that a region encoding non-translated RNAs, expressed solely within the brain, can regulate bone mass in health and disease.

Adults with Prader-Willi syndrome have weaker bones: effect of treatment with GH and sex steroids

Obesity has been considered to have a protective effect against the risk of fractures in adults. However, a high frequency of fracture is described in obese adults with Prader-Willi syndrome. To evaluate bone geometry, density and strength in a group of adult obese patients with Prader-Willi syndrome (PWS) and to examine the modulating effect on bone of treatment with growth hormone (GH) and sex steroids. This was a cross-sectional study performed in 41 (17 males, 24 females) obese subjects with genetically confirmed PWS, aged 29.4 ± 8.6 years. Forty-six healthy subjects (22 males and 24 females) served as controls. Digitalized X-rays were evaluated at the level of the 2nd metacarpal bone to assess bone geometry, i.e. cross-sectional area (CSA), cortical area (CA), medullary area (MA), metacarpal index (MI) and bone strength evaluated as bending breaking resistance index (BBRI). DEXA was also used to evaluate body composition and bone mineral density (total body, lumbar spine and femoral neck). PWS subjects, after adjusting for height and bone size, had a reduced CSA, CA and BBRI, while bone density was not different. GH treatment had a positive effect and sex steroids a negative effect on bone size and strength. PWS subjects showed a reduced bone size at the metacarpus leading to a reduced strength, while bone density was appropriate for size. GH treatment improves bone geometry but not bone density. Bone strength was significantly reduced in PWS patients who did not receive GH and had been treated with sex steroids.

Growth hormone treatment for osteoporosis in patients with scoliosis of Prader-Willi syndrome

BACKGROUND

Patients with Prader-Willi syndrome (PWS) have fragile bones. Osteoporosis is a major concern in scoliosis surgery. Our aim was to investigate bone mineral density (BMD) in PWS patients and to verify the efficacy of and scoliosis deterioration with growth hormone (GH) administration for osteoporosis.

METHODS

We followed 148 PWS patients who underwent lumbar spine (L2-4) BMD testing. Sixty-four patients had scoliosis, and 84 were non-scoliosis patients. Patients were treated with GH (0.245 mg/kg/week) until they reached a skeletal age of 17 years for males and 15 years for females. We also evaluated the effect of GH treatment on BMD in 101 patients (60 males, 41 females) undergoing BMD testing more than twice. The mean patient age was 5.4 years. The mean duration of GH administration was 54 months.

RESULTS

Mean lumbar BMD was 0.567 g/cm(2). Fifty patients (33.8%) had osteoporosis and 41 (27.7%) had osteopenia. There was no significant difference in mean BMD between patients with scoliosis (0.598 g/cm(2)) and without scoliosis (0.548 g/cm(2)). GH treatment caused a significant increase in Z score (pre-GH: mean -2.28 vs. post-GH: mean -1.53, P < 0.001). There was no statistical difference in the prevalence of scoliosis between the GH treatment group (45/112, 40.1%) and non-treatment group (19/36, 52.8%).

CONCLUSIONS

Among patients with PWS, 61.5% had low BMDs. GH administration significantly improved the lumbar BMD (Z score). There were no statistically significant differences in the prevalence of scoliosis among patients who received GH treatment compared to patients who did not.

Update on body composition and bone density in children with Prader-Willi syndrome

AIM

To compare body composition in children with Prader-Willi syndrome (PWS) not naïve to growth hormone (GH) with obese and lean controls.

METHODS

Participants included 12 children with PWS, 12 children with obesity (body fat percentage >95th percentile for age and sex) and 12 lean children (body fat percentage <85th percentile for age and sex) matched by age and height. Fat mass, lean mass, bone mineral content (BMC), bone mineral density (BMD) and BMD z-score for total body, hips and lumbar spine were obtained through dual X-ray absorptiometry.

RESULTS

PWS had higher fat percentage in the legs (p = 0.04) but similar leg fat mass (p = 1.00) compared to obese. PWS exhibited lower lean mass in the body (p = 0.04) and legs (p = 0.02) than obese, but similar to lean (p = 1.00 and p = 0.89, respectively). PWS had lower hip BMC (p < 0.01), BMD (p < 0.01) and BMD z-score (p < 0.01) compared to obese but similar to lean. No other differences were found between PWS and obese (p > 0.05 for all).

CONCLUSIONS

Children with PWS not naïve to GH present differences in fat and lean mass distribution compared to obese controls. BMC and BMD appear unaffected by PWS, except at the hips.

Current status of growth hormone therapy in Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a complex genetic disorder characterized by muscular hypotonia, hypogonadism, short stature, hyperphagia, obesity, cognitive disabilities and behavioral problems. Body composition is abnormal and growth hormone (GH) secretion is insufficient with more body fat than lean body mass. In children with PWS treatment with GH improves height, head size, body composition and psychomotor functioning. In adults with PWS treatment with GH improves body composition, physical activity and quality of life. However, restricted diet and regular physical exercise are cornerstone treatments in PWS also during GH treatment. GH treatment should be considered in PWS patients with a genetically confirmed diagnosis. Cognitive disabilities and scoliosis are not contraindications to GH treatment. Adverse effects to GH treatment in PWS are few, but glucose metabolism and changes in respiration must be monitored carefully, especially in individuals with predispositions. GH treatment should be continued as long as benefits outweigh the risks.

Testosterone replacement therapy to improve secondary sexual characteristics and body composition without adverse behavioral problems in adult male patients with Prader-Willi syndrome: an observational study

Prader-Willi syndrome (PWS), a complex genetic disorder, arises from suppressed expression of paternally inherited imprinted genes on chromosome 15q11-q13. Characteristics include short stature, intellectual disability, behavioral problems, hypogonadism, obesity, and reduced bone and muscle mass. Testosterone replacement (TR) remains controversial due to concerns regarding behavioral problems. To evaluate the effects of TR on secondary sexual characteristics, body composition, and behavior in adult males with PWS, 22 male PWS patients over the age of 16 with behavioral scores of less than grade 4 on the Modified Overt Aggression Scale (MOAS) underwent monthly intramuscular TR (125 mg). Pubertal change, body composition and behavior were evaluated before and after 24 months of therapy. Serum testosterone, LH, and FSH did not change. Increased pubic hair was observed in 16 of 22 patients (72.7%). Percent body fat decreased from 47.55 ± 2.06% to 39.75 ± 1.60% (n = 18) (P = 0.018). Bone mineral density increased from 0.8505 ± 0.0426 g/cm(2) to 0.9035 ± 0.0465 g/cm(2) (n = 18) (P = 0.036), and lean body mass increased from 18093.4 ± 863.0 g to 20312.1 ± 1027.2 g (n = 18) (P = 0.009). The MOAS was unchanged, from 4.5 ± 2.0 at the beginning of the study to 3.0 ± 1.7 at the end of study indicating no increase in aggression. No behavioral problems were observed. Based on this pilot study, TR with 125 mg monthly is a potentially safe and useful intervention for adult males with PWS.

Comparison of body composition, basal metabolic rate and metabolic outcomes of adults with Prader Willi syndrome or lesional hypothalamic disease, with primary obesity

CONTEXT

The care of patients with hypothalamic obesity is challenging.

OBJECTIVE

To compare body composition, basal metabolic rate (BMR) and metabolic outcomes of adults, with lesional or genetic hypothalamic obesity, with obese patients suffering from primary obesity, once matched for body mass index (BMI).

DESIGN AND PATIENTS

Adults with hypothalamic obesity of genetic origin (Prader Willi syndrome (PWS)) or acquired hypothalamic damage (HD), such as craniopharygioma, were compared with obese control candidates awaiting bariatric surgery (C), with a BMI between 35 and 65 kg m(-)(2), and aged between 18 and 50 years.

MAIN OUTCOME MEASURES

Body composition measured by whole-body dual-energy X-ray absorptiometry scanning, BMR using indirect calorimetry, hormonal and metabolic assessments.

RESULTS

A total of 27 adults with a genetic diagnosis of PWS, 15 obese subjects with HD and 206 obese controls with similar BMI were studied. Compared with the control group, PWS patients had an increased percentage of fat mass (FM), and a decreased percentage of android FM. The BMR of PWS patients was significantly lower than controls and highly correlated with lean body mass in PWS and C patients. Body composition of HD was similar with those of obese patients. A trend toward an increased prevalence of diabetes in HD patients and of cytolysis in PWS was observed in comparison with primary obese patients.

CONCLUSION

Genetic and lesional hypothalamic obesities have different consequences for phenotypic features such as body composition or BMR compared with primary obese patients. The mechanisms of adipose tissue development and metabolic complications may be different between genetic and lesional obesities.

Effects of adiposity and Prader-Willi Syndrome on postexercise heart rate recovery

Heart rate recovery (HRR) is an indicator of all-cause mortality in children and adults. We aimed to determine the effect of adiposity and Prader-Willi Syndrome (PWS), a congenital form of obesity, on HRR. Sixteen children of normal weight (NW = body fat % ≤85th percentile, 9.4 ± 1.1 y), 18 children with obesity (OB = body fat % >95th percentile, 9.3 ± 1.1 y), and 11 PWS youth (regardless of body fat %; 11.4 ± 2.5 y) completed peak and submaximal bike tests on separate visits. HRR was recorded one minute following peak and submaximal exercises. All groups displayed similar HRR from peak exercise, while NW (54 ± 16 beats) and OB (50 ± 12 beats) exhibited a significantly faster HRR from submaximal exercise than PWS (37 ± 14 beats). These data suggest that excess adiposity does not influence HRR in children, but other factors such as low cardiovascular fitness and/or autonomic dysfunction might be more influential.

The effect of growth hormone treatment or physical training on motor performance in Prader-Willi syndrome: a systematic review

Although motor problems in Prader-Willi syndrome (PWS) are prominent in infants, and continue into childhood and adulthood, there is little insight into the factors important for clinical management. The literature was reviewed to: (1) provide an overview of the characteristics and prevalence of motor problems and (2) evaluate the effects of growth hormone (GH) treatment and physical training on motor performance. A systematic search revealed 34 papers: 13 on motor performance; 12 on GH treatment; and nine on physical training. In infants, motor development is 30-57% of the normal reference values, and children and adults also have significant problems in skill acquisition, muscle force, cardiovascular fitness, and activity level. GH treatment positively influenced motor performance in infants, children, and adults, although not all studies demonstrated an effect. All studies on physical training demonstrated beneficial effects in PWS patients. We suggest a combination of GH treatment and physical training to be started as soon as possible, especially in infants, to improve motor development as this will positively influence general development.

Growth hormone treatment in adults with Prader-Willi syndrome: the Scandinavian study

Prader-Willi syndrome (PWS) is characterized by short stature, muscular hypotonia, cognitive dysfunction, and hyperphagia usually leading to severe obesity. Patients with PWS share similarities with growth hormone deficiency (GHD). Few studies have dealt with growth hormone (GH) treatment in PWS adults. The purpose of the Scandinavian study was to evaluate the effects of GH on body composition, lipid and glucose metabolism, physical performance and safety parameters in adults with PWS. Twenty-five women and 21 men with PWS were randomized to treatment with GH or placebo during 1 year followed by 2 years of open labeled GH treatment. At baseline 1/3 had normal BMI, six patients severe GHD, ten impaired glucose tolerance and seven diabetes. At 1 year insulin-like growth factor I (IGF-I) SDS had increased by 1.51 (P < 0.001) and body composition improved in the GH treated group. Visceral fat decreased by 22.9 ml (P = 0.004), abdominal subcutaneous fat by 70.9 ml (P = 0.003) and thigh fat by 21.3 ml (P = 0.013), whereas thigh muscle increased 6.0 ml (P = 0.005). Lean body mass increased 2.25 kg (P = 0.005), and total fat mass decreased 4.20 kg (P < 0.001). The positive effects on body composition were maintained after 2 years of GH treatment. Peak expiratory flow increased by 12% (P < 0.001) at 2 years of GH treatment. Lipid and glucose metabolism were unchanged, however, three patients developed diabetes at 2 years of GH treatment. In conclusion GH treatment had beneficial effects on the abnormal body composition without serious adverse events making it a logic treatment option in adults with PWS.

Muscle-bone characteristics in children with Prader-Willi syndrome

BACKGROUND

A decrease in muscle mass, low motor performance, and normal lumbar spine bone mineral density (BMD) have been reported in children with Prader-Willi syndrome (PWS). However, these data are limited by the fact that PWS children (who have short stature) were compared to age-matched healthy or obese individuals of normal height.

OBJECTIVE

The goal of the present study was to compare bone and muscle characteristics in PWS children to sex- and age- or height-matched healthy subjects.

MATERIALS AND METHODS

The study population included 17 PWS children (ages 6.2 to 17.5 yr; nine girls) who were not treated with GH. The axial skeleton was analyzed at the lumbar spine using dual-energy x-ray absorptiometry, and the appendicular skeleton (radius and tibia) was evaluated using peripheral quantitative computed tomography. Muscle parameters (mass, size, and functional parameters) were measured by dual-energy x-ray absorptiometry, peripheral quantitative computed tomography, and jumping mechanography, respectively.

RESULTS

Compared to height-matched controls, PWS patients had normal axial and appendicular BMD, as well as normal muscle size. Compared to age- or height-matched controls of normal weight, PWS patients had lower maximal muscle force and power relative to body mass during jumping. PWS patients had similar absolute maximal muscle force but lower absolute maximal power compared to age- or height-matched controls. Relationships between bone mass and muscle size and force were similar in PWS patients and in healthy subjects.

CONCLUSION

Relative to their height, PWS patients not treated with GH had normal axial and appendicular BMD, muscle size, and muscle-bone relationships.

Prader-willi syndrome: clinical aspects

Prader-Willi Syndrome (PWS) is a complex multisystem genetic disorder that shows great variability, with changing clinical features during a patient's life. The syndrome is due to the loss of expression of several genes encoded on the proximal long arm of chromosome 15 (15q11.2-q13). The complex phenotype is most probably caused by a hypothalamic dysfunction that is responsible for hormonal dysfunctions and for absence of the sense of satiety. For this reason a Prader-Willi (PW) child develops hyperphagia during the initial stage of infancy that can lead to obesity and its complications. During infancy many PW child display a range of behavioural problems that become more noticeable in adolescence and adulthood and interfere mostly with quality of life. Early diagnosis of PWS is important for effective long-term management, and a precocious multidisciplinary approach is fundamental to improve quality of life, prevent complications, and prolong life expectancy.

Specific treatment of Prader-Willi syndrome through cyclical rehabilitation programmes

PURPOSE

 To evaluate retrospectively the efficiency of our rehabilitation programme for patients with Prader-Willi Syndrome. In total, 49 patients were examined, 21 female and 28 male, the youngest in their late teens. Prader-Willi syndrome is generally characterised by cognitive impairment, behavioural abnormalities, and hyperphagia. Patients are usually considerably adverse to any form of physical exercise, and despite hormonal therapy, weight control in adult patients can be difficult.

METHODS

 Four times a year, disease-specific residential programmes were organised, each lasting 4 weeks. The patients were restricted to a 1500 Kcal diet. In addition, they were required to do 6.5 h of physical exercise daily, stamina being built up by using music therapy, psychomotor therapy, education and entertainment activities.

RESULTS

BMI decreased by 2.1 average points in every residential session. For three patients who attended our treatments regularly, a reduction of 8.9 points over 6 years was recorded. An attendance of at least three sessions per year seemed to be necessary to substantially reduce weight.

CONCLUSIONS

A multidisciplinary approach and a daily calorie-counted diet can lead to significant weight loss in teenage and adult PWS patients. This approach would also be suitable in treating patients with other obesity syndromes with mental retardation.

Obesity in disabled children and adolescents: an overlooked group of patients

BACKGROUND

There is an ongoing debate concerning the relationship between disability and obesity in childhood and adolescence.

METHODS

The literature available in Medline was selectively searched for the terms: "(children /OR/ adolescents) /AND/ disability /AND/ (overweight /OR/ obesity)". This search was complemented by inspection of journals in the fields of obesity, pediatrics, and neurology.

RESULTS

A total of 38 relevant articles were identified. All studies agreed that the prevalence of overweight and obesity in children with disabilities was almost twice that in their non-disabled peers. No effective, long-lasting interventions for obesity in disabled children and adolescents have been published.

CONCLUSION

Since a high proportion of disabled children and adolescents are overweight or obese, effective strategies for preventing and managing excess weight need to be developed so as not to further endanger their social participation. Moreover, risk factors for overweight in disabled children and adolescents should be identified and their weight status carefully monitored.

Bone mineral density and effects of growth hormone treatment in prepubertal children with Prader-Willi syndrome: a randomized controlled trial

BACKGROUND

Bone mineral density (BMD) is unknown in children with Prader-Willi syndrome (PWS), but is decreased in adults with PWS. In patients with GH deficiency, BMD increases during GH treatment.

OBJECTIVES

The aim of the study was to evaluate BMD in children with PWS and to study the effects of GH treatment.

DESIGN

We conducted a randomized controlled GH trial. Forty-six prepubertal children were randomized into either a GH-treated group (1.0 mg/m(2) . d) or a control group for 2 yr. At start, 6, 12, and 24 months of study, total body and lumbar spine BMD were measured by dual-energy x-ray absorptiometry, and lumbar spine bone mineral apparent density (BMAD) was calculated.

RESULTS

Baseline total body and lumbar spine BMD sd score (SDS) were normal [mean (sd), -0.2 SDS (1.1) and -0.4 SDS (1.2), respectively]. BMADSDS, which corrects for short stature, was also normal [mean (sd), 0.40 SDS (1.1)]. Total body BMDSDS decreased during the first 6 months of GH (P < 0.0001), but increased during the second year of treatment. After 24 months of study, total body and lumbar spine BMDSDS, and the BMADSDS did not significantly differ between GH-treated children and randomized controls (P = 0.30, P = 0.44, and P = 0.47, respectively). Results were similar when corrected for body mass index SDS. Repeated measurements analysis showed a significant positive association between IGF-I SDS and total body and lumbar spine BMDSDS, but not with BMADSDS.

CONCLUSIONS

Our results show that prepubertal children with PWS have a normal BMD. GH treatment had no effect on BMD, except for a temporary decrease of total body BMDSDS in the first 6 months.

Everyday physical activity and adiposity in Prader-Willi syndrome

The aim of this study was to assess the impact of Prader-Willi syndrome (PWS) on the level of everyday physical activity and to explore whether the activity level is related to adiposity. Measurements were performed with an accelerometry-based Activity Monitor during two consecutive schooldays in 12 children with PWS (7-16 years of age) and in 12 age- and gender-matched, healthy children. Adiposity was assessed by body mass index standard deviation scores and by percentage body fat (dual energy X-ray absorptiometry). Mean duration of dynamic activities (expressed as percentage of 24 h) was lower in children with PWS than in the comparison group (8.7 [2.5]% and 12.0 [3.1]%, respectively; p = 0.01). Six children with PWS had normal activity levels. Physical activity level was not related to adiposity. The results indicate that, as a group, children with PWS have an inactive lifestyle. However, children with PWS cannot be stereotyped as inactive since half of them had normal activity levels.

Growth hormone therapy improves exercise capacity in adult patients with Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is associated with an inappropriate proportion of fat mass (FM) to non-FM compared to simple obesity. Altered body composition in PWS resembles that seen in subjects with GH deficiency, in which a reduction of lean body mass (LBM) is observed. The low LBM may contribute to the reduced motor skills seen in PWS patients.

AIM

The objective of the study was to investigate the effects of GH therapy on exercise capacity and body composition in a group of adult subjects with PWS.

SUBJECTS AND METHODS

Twelve PWS adults (7 males and 5 females, aged 26.4+/-4.4 yr, body mass index 44.3+/-4.6 kg/m2) participated in the study. Body composition analysis and exercise stress test were carried out throughout the 12 months GH therapy. Body composition was measured by Dual Energy X-ray Absorptiometry. Physical performance was evaluated using treadmill exercise test. Exercise intensity was expressed as metabolic equivalents (MET, 1 MET= 3.5 ml O2 kg(-1) min(-1)). Statistical analysis was performed by repeated-measures analysis of variance followed by post-hoc analysis with t test for paired data for comparisons among the different follow ups.

RESULTS

Compared to baseline GH therapy increased LBM at 6 (p<0.0001) and 12 months (p<0.005) (45.3+/-7.7 kg vs 48.6+/-6.7 kg vs 48.2+/-7.5 kg). FM% was significantly reduced both after 6 and 12 months (p<0.02) (56.1+/-4.8% vs 53.7+/-4.2% vs 53.3+/-4.8%). Attained MET were found to be improved by 16% after 6 months and by 19% after 12 months of GH (p<0.001), while the small further rise between 6 and 12 months was not significant.

CONCLUSIONS

Our findings seem to support the view that GH therapy has beneficial effects on physical activity and agility as well as on body composition of adult patients with PWS.

Obesity and secondary conditions in adolescents with disabilities: addressing the needs of an underserved population

Children and adolescents with physical and cognitive disabilities have a higher prevalence of overweight compared to their non-disabled peers. This health risk can lead to a greater number of obesity-related secondary conditions (e.g., fatigue, pain, deconditioning, social isolation, difficulty performing activities of daily living) and can impose significant personal and economic hardship on the child and family. Effective strategies for reducing the risk of overweight/obesity in adolescents with disabilities must begin with greater awareness of the behavioral and environmental antecedents that lead to higher rates of obesity in this underserved segment of the youth population. Research on interventions to reduce obesity among adolescents with disabilities is an important area of future research for public health scientists. A range of interventions will be necessary to overcome the many barriers that youth with disabilities experience in achieving and maintaining a healthy weight.

The effect of growth hormone on the response of total and acylated ghrelin to a standardized oral glucose load and insulin resistance in children with Prader-Willi syndrome

CONTEXT

Fasting levels of plasma ghrelins are grossly elevated in children with Prader-Willi syndrome (PWS). The cause of this elevation and the regulation of ghrelins in PWS is largely unknown. The regulatory role of individual nutritional components and of GH is not well characterized.

OBJECTIVE

We investigated the influence of GH on acylated (aGhr) and total ghrelin (tGhr) concentrations before and after an oral glucose load, and on insulin resistance in PWS children.

DESIGN, PATIENTS, AND INTERVENTIONS

In a clinical follow-up study, plasma ghrelins were measured during an oral glucose tolerance test, and parameters of insulin resistance were determined in 28 PWS children before and/or 1.18 (0.42-9.6) yr (median, range) after start of GH therapy (0.035 mg/kg body weight per day).

MAIN OUTCOME MEASURES

Fasting and postglucose concentrations of aGhr and tGhr and homeostasis model assessment 2 insulin resistance were the main outcome measures.

SETTING

The study was conducted in a single center (University Children's Hospital).

RESULTS

High fasting [1060 +/- 292 (sd) pg/ml; n = 12] and postglucose trough (801 +/- 303 pg/ml; n = 10) tGhr concentrations in GH-untreated PWS children were found to be decreased in the GH-treated group (fasting 761 +/- 247 pg/ml, n = 24, P = 0.006; postglucose 500 +/- 176 pg/ml, n = 20; P = 0.006). In contrast, aGhr concentrations and insulin resistance were not changed by GH treatment. Both aGhr and tGhr concentrations were decreased by oral carbohydrate administration, independent of the GH treatment status.

CONCLUSIONS

Our results indicate that, in PWS children, aGhr and tGhr are differentially regulated by GH.

Adrenarche in Prader-Willi syndrome appears not related to insulin sensitivity and serum adiponectin

Prader-Willi syndrome (PWS) is a genetic disorder characterized by dysmorphic features, obesity, hypogonadism, hypotonia and mental retardation. Obesity has been linked to insulin resistance and the latter has also been associated with premature adrenarche. Since up to date a controlled study to investigate adrenarche and its hormonal regulation was lacking in PWS, our aim was to assess whether prepubertal PWS patients develop premature adrenarche and its relationship with markers of insulin sensitivity. Fourteen prepubertal children with PWS (6 M, 8 F) and 10 non-syndromal simple obese matched controls (5 M, 5 F) participated (mean age: 7.62 +/- 1.84 years). A fasting blood sample was obtained for adrenal and ovarian androgens, sex hormone binding globulin, insulin-like growth factor-I (IGF-I), insulin-like growth factor binding protein-1, leptin, adiponectin and a lipid profile. Thereafter an oral glucose tolerance test was performed. PWS patients were smaller at birth and a higher proportion displayed premature pubarche. No differences were found in testosterone, androstenedione, sex hormone binding globulin, free androgen index, homeostatic model assessment-IR, 2-hour insulin, leptin or adiponectin levels. 17-hydroxyprogesterone and DHEAS levels however, were significantly higher in PWS. IGF-I levels were significantly lower in PWS and correlated significantly with height SDS (p < 0.05). In conclusion, a higher proportion of premature adrenarche in our PW patients was observed, which was not explained by differences in insulin sensitivity or plasma levels of adipokines and IGF-I.

Reduced exercise-associated response of the GH-IGF-I axis and catecholamines in obese children and adolescents

Obesity blunts catecholamine and growth hormone (GH) responses to exercise in adults, but the effect of obesity on these exercise-associated hormonal responses in children is unclear. Therefore, the aim of the present study was to asses the effect of childhood obesity on the counterregulatory hormonal response to acute exercise. Twenty-five obese children (Ob; body mass index > 95%), and 25 age, gender, and maturity-matched normal-weight controls (NW) participated in the study. Exercise consisted of ten 2-min bouts of constant-cycle ergometry above the anaerobic threshold, with 1-min rest intervals between each bout. Pre-, post-, and 120-min postexercise blood samples were collected for circulating components of the GH-IGF-I axis and catecholamines. There were no differences in peak exercise heart rate, serum lactate, and peak O2 uptake normalized to lean body mass between the groups. Obesity attenuated the GH response to exercise (8.9 +/- 1.1 vs. 3.4 +/- 0.7 ng/ml in NW and Ob participants, respectively; P < 0.02). No significant differences in the response to exercise were found for other components of the GH-IGF-I axis. Obesity attenuated the catecholamine response to exercise (epinephrine: 52.5 +/- 12.7 vs. 18.7 +/- 3.7 pg/ml, P < 0.02; norepinephrine: 479.5 +/- 109.9 vs. 218.0 +/- 26.0 pg/ml, P < 0.04; dopamine: 17.2 +/- 2.9 vs. 3.5 +/- 1.9 pg/ml, P < 0.006 in NW and Ob, respectively). Insulin levels were significantly higher in the obese children and dropped significantly after exercise in both groups. Despite the elevated insulin levels and the blunted counterregulatory response, none of the participants developed hypoglycemia. Childhood obesity was associated with attenuated GH and catecholamine response to acute exercise. These abnormalities were compensated for, so that exercise was not associated with hypoglycemia, despite increased insulin levels in obese children.

A female with Angelman syndrome and unusual limb deformities

This report presents the case of a 13-year-old female with Angelman syndrome caused by 15q11-13 microdeletion demonstrating unusual marked limb deformities with generalized osteoporosis, delayed bone age, and brachydactyly type B. The radiographs of her femur, tibia, fibula, ulna, and radius revealed curved deformities in the distal diaphysis-metaphysis areas and generalized osteoporosis. This can be explained by the patient's severe disability, delayed puberty, presumed nutritional and environmental deficits, or rickets. In addition, she had shortening of the distal phalanges of all fingers, the absence of some epiphyses of the distal phalanges, and hypertrophic and curved III metacarpal bones. These clinical findings could not be explained by classical rickets or osteoporosis, but can be classified as brachydactyly type B. To our knowledge, such marked limb deformities and brachydactyly have not previously been described in patients with Angelman syndrome.

Growth hormone improves mobility and body composition in infants and toddlers with Prader-Willi syndrome

OBJECTIVES

To determine the effect of growth hormone (GH) on body composition and motor development in infants and toddlers with Prader-Willi syndrome (PWS).

STUDY DESIGN

Twenty-nine subjects with PWS (4-37 months of age) were randomized to GH treatment (1mg/m 2 /day) or observation for 12 months. Percent body fat, lean body mass, and bone mineral density were measured by dual x-ray absorptiometry; energy expenditure was measured by deuterium dilution; and motor constructs of mobility (M) and stability (S) were assessed using the Toddler Infant Motor Evaluation (TIME).

RESULTS

GH-treated subjects, compared with controls, demonstrated decreased percent body fat (mean, 22.6% +/- 8.9% vs 28.5% +/- 7.9%; P < .001), increased lean body mass (mean, 9.82 +/- 1.9 kg vs 6.3 +/- 1.9 kg; P < .001), and increased height velocity Z scores (mean, 5. 0 +/- 1.8 vs 1.4 +/- 1.0; P < .001). Patients who began GH before 18 months of age showed higher mobility skill acquisition compared with controls within the same age range (mean increase in raw score, 284 +/- 105 vs 206 +/- 63; P < .05).

CONCLUSIONS

GH treatment of infants and toddlers with PWS for 12 months significantly improves body composition and when begun before 18 months of age increases mobility skill acquisition. These results suggest that GH therapy instituted early in life may lessen deterioration of body composition in PWS while also accelerating motor development.

Growth hormone and body composition in children younger than 2 years with Prader-Willi syndrome

OBJECTIVES

To assess body composition of infants with Prader-Willi syndrome (PWS) by using deuterium dilution and investigating the efficacy of early institution of growth hormone (GH) therapy in increasing lean mass (LM) and preventing massive obesity.

STUDY DESIGN

One group of 11 children with PWS <2 years before and during 30-month GH therapy (GH group) was compared with 6 infants administered only coenzyme Q(10) for 1 year (Q10 group). LM adjusted for height (LM(Ht)) and relative fat mass (%FM(Age)) standard deviation scores (SDS) were calculated from data of 95 healthy children.

RESULTS

Initially, LM(Ht) of all patients was below the normal average. LM(Ht) decreased by -0.46 +/- 0.3 SD (P=.03) per year in the Q10 group but rose by 0.25 +/- 0.3 SD (P=.02) per year during GH therapy, normalizing after 30 months (-0.70 +/- 1.0 SD). Despite low to normal weight for height (WfH), %FM(Age) was above the normal average (GH group, 31.0% +/- 4.5%, Q10 group, 32.4% +/- 9.5%). In the Q10 infants, %FM(Age) increased by 0.71 +/- 0.7 SD per year, whereas in the GH group, %FM(Age) remained more stable up to 30 months.

CONCLUSIONS

Diminished LM(Ht) found in infants with PWS further declines during the early years. Early institution of GH therapy lifts LM(Ht) into the normal range and delays fat tissue accumulation.

Decreased energy expenditure is caused by abnormal body composition in infants with Prader-Willi Syndrome

OBJECTIVE

Infants with Prader-Willi syndrome (PWS) are hypotonic and underweight before the onset of childhood obesity. This study evaluates body composition in the PWS infant and its relationship to energy expenditure.

STUDY DESIGN

Sixteen infants and toddlers with PWS (mean age, 12.4+/-6 months; eight female subjects) underwent analysis of body composition with dual-energy x-ray absorptiometry and deuterium dilution, and energy expenditure with both doubly labeled water and indirect calorimetry.

RESULTS

Percent body fat was significantly increased (male subjects, P<.001; female subjects, P<.001) and fat-free mass (FFM) was significantly decreased (male subjects, P<.001; female subjects, P=.04) in infants with PWS when compared with age-matched published data for normal infants. Meanwhile, total energy expenditure was significantly decreased (male subjects, P=.025; female subjects, P<.001) in infants with PWS when compared with published normative data. There was a normal relationship between FFM and total energy expenditure in infants with PWS.

CONCLUSION

Compared with published data for infants without PWS, infants with PWS demonstrate increased percent body fat, decreased FFM, and decreased energy expenditure. Importantly, total energy expenditure per kilogram of FFM appears similar in infants with and without PWS. We conclude that lower energy expenditure in infants with PWS is caused by decreased FFM.

Prader-Willi syndrome and the evolution of human childhood

The kinship theory of genomic imprinting predicts that imprinted genes have effects on asymmetric kin (relatives with different degrees of matrilineal and patrilineal relatedness). The most important interaction with such a relative is a child's interaction with its mother. Therefore, the study of imprinted genes and their phenotypic effects promises to provide insights into the evolution of mother-child relations. Prader-Willi syndrome (PWS) is caused by the absence of expression of genes at 15q11-q13 that are normally expressed only when paternally derived. The kinship theory predicts that children with PWS will fail to express behaviors that have increased mothers' costs of child-rearing. Our analysis focuses on aspects of the PWS phenotype that affect appetite and feeding. Immediately after birth, children with PWS have little appetite and are usually unable to suckle, but at some stage (usually within the first 2 years) they develop a voracious appetite and an obsession with food. We conjecture that this change in appetite reflects evolutionary forces associated with weaning. Immediately after birth, when a child is completely dependent on the breast, poor appetite reduced maternal costs. However, once a child was able to consume supplemental foods, maternal costs would have been reduced by children with increased, nonfastidious appetites.

Improving body composition and physical activity in Prader-Willi Syndrome

OBJECTIVE

To determine if muscle training in Prader-Willi Syndrome (PWS) can improve local body composition, physical capacity, and activity.

STUDY DESIGN

Seventeen children and adolescents with PWS and 18 control children were enrolled in a daily short calf muscle training program for 3 months. Before (t(0)) and after 3 months of training (t(3m)), spontaneous physical activity and exercise capacity were assessed by pedometer registrations and activity protocols. Local body composition was determined by calf circumference and skinfold measurements at t(0), t(3m), and 3 months after t(3m) (t(6m)).

RESULTS

During training, calf skinfold decreased from 1.1 to 0.8 SD (P <.01) and calf circumference in PWS increased from 1.4 to 1.9 SD (P <.05), reflecting improved muscle mass. At t(3m), a significant increase in spontaneous physical activity (from 45% to 71%, compared with baseline data of control children, P <.05) and physical capacity (from 31%-78%, P <.01) was found.

CONCLUSIONS

In persons with PWS, a well-defined and easy-to-accomplish training program improves local body composition and has generalized effects on physical activity and capacity, opening up a new therapeutic option to improve metabolic conditions.