Growth hormone treatment in Prader-Willi syndrome patients: systematic review and meta-analysis

GH Therapy in Non-Growth Hormone-Deficient Children

Before 1985, growth hormone (GH) was extracted from human pituitaries, and its therapeutic use was limited to children with severe GH deficiency (GHD). The availability of an unlimited amount of recombinant GH (rhGH) allowed for investigating the efficacy of its therapeutic use in a number of conditions other than GHD. Nowadays, patients with Turner syndrome, SHOX deficiency, Noonan syndrome, Prader-Willi syndrome, idiopathic short stature, chronic kidney disease, and children born small for gestational age can be treated with rhGH in order to improve adult height. In patients with Prader-Willi syndrome, rhGH therapy also improves body composition and cognitive function. Large post-marketing multinational studies in a large number of pediatric patients demonstrated a good safety profile for rhGH. Recently, long-acting formulations of rhGH have been approved and licensed for GHD, and clinical trials are ongoing for other conditions. In this paper, we review the rhGH therapy in children with conditions other than GHD.

Childhood growth hormone treatment: challenges, opportunities, and considerations

With long standing demand and popularity, growth hormone treatments continue to be a topic of interest for paediatric endocrinologists and general paediatricians due to ongoing issues regarding their long-term effects, the safety of childhood treatment, and the introduction of long-acting growth hormone preparations in the past decade. Moreover, uncertainty regarding how to approach individual patients and their treatment indications remains, particularly concerning tailored treatment goals and objectives; this uncertainty is further complicated by the multitude of approved indications that surpass substitution therapy. The paediatric endocrinologist thus grapples with pertinent questions, such as what defines reasonable treatment goals for each individual given their indications, and when (and how) to initiate the necessary discussions about risks and benefits with patients and their families. The aim of this Review is to offer advanced physiological concepts of growth hormone function, map out approved paediatric indications for treatment along with evidence on their effects and safety, highlight controversies and complexities surrounding childhood growth hormone treatment, and discuss the potential of long-acting growth hormone and future directions in the realm of childhood growth hormone treatment.

Prader-Willi syndrome: guidance for children and transition into adulthood

Prader-Willi syndrome (PWS) is a rare orphan disease and complex genetic neurodevelopmental disorder, with a birth incidence of approximately 1 in 10,000-30,000. Management of people with PWS requires a multi-disciplinary approach, ideally through a multi-disciplinary team (MDT) clinic with community support. Hypotonia, poor feeding and faltering growth are characteristic features in the neonatal period, followed by hyperphagia and risk of rapid weight gain later in childhood. Children and adolescents (CA) with PWS usually display developmental delay and mild learning disability and can develop endocrinopathies, scoliosis, respiratory difficulties (both central and obstructive sleep apnoea), challenging behaviours, skin picking, and mental health issues, especially into adulthood. This consensus statement is intended to be a reference document for clinicians managing children and adolescents (up to 18 years of age) with PWS. It considers the bio-psycho-social domains of diagnosis, clinical assessment, and management in the paediatric setting as well as during and after transition to adult services. The guidance has been developed from information gathered from peer-reviewed scientific reports and from the expertise of a range of experienced clinicians in the United Kingdom and Ireland involved in the care of patients with PWS.

Efficacy of Human Recombinant Growth Hormone in Females of a Non-Obese Hyperglycemic Mouse Model after Birth with Low Birth Weight

We examined whether the administration of growth hormone (GH) improves insulin resistance in females of a non-obese hyperglycemic mouse model after birth with low birth weight (LBW), given that GH is known to increase muscle mass. The intrauterine Ischemia group underwent uterine artery occlusion for 15 min on day 16.5 of gestation. At 4 weeks of age, female mice in the Ischemia group were divided into the GH-treated (Ischemia-GH) and non-GH-treated (Ischemia) groups. At 8 weeks of age, the glucose metabolism, muscle pathology, and metabolome of liver were assessed. The insulin resistance index improved in the Ischemia-GH group compared with the Ischemia group (p = 0.034). The percentage of type 1 muscle fibers was higher in the Ischemia-GH group than the Ischemia group (p < 0.001); the muscle fiber type was altered by GH. In the liver, oxidative stress factors were reduced, and ATP production was increased in the Ischemia-GH group compared to the Ischemia group (p = 0.014), indicating the improved mitochondrial function of liver. GH administration is effective in improving insulin resistance by increasing the content of type 1 muscle fibers and improving mitochondrial function of liver in our non-obese hyperglycemic mouse model after birth with LBW.

Prader-Willi syndrome in a large sample from Spain: general features, obesity and regular use of psychotropic medication

BACKGROUND

Prader-Willi syndrome (PWS), a genetically determined disorder, the most frequent cause of early onset obesity, is associated with physical and cognitive dysfunctions and behavioural disturbances; these disturbances are frequently treated with psychotropic medication. The aim of this cross-sectional study was to describe the characteristics of the first large national sample of persons with PWS in Spain and analyse the relationships of those characteristics with key demographic and clinical factors, particularly with obesity and the regular use of psychotropic medication.

METHODS

Participants were recruited among all members of the Spanish Prader-Willi Association who agreed to take part in the study and fulfilled its inclusion criteria. Family and patient demographic features, family size and birth order, intelligence quotient (IQ), anthropometric measures, lifestyle habits, behavioural disturbances (with the Aberrant Behavior Checklist) and clinical data, as well as use of psychotropic drugs and their side effects (with the UKU scale), were collected in genetically confirmed cases of PWS. Bivariate and logistic regression analyses were used for determining the associations of demographic and clinical factors with both obesity and the regular use of psychotropic medication.

RESULTS

The cohort included 177 participants (aged 6-48 years), that is, 90 (50.8%) males and 87 (49.2%) females. Behavioural disturbances were present in a range of 75% to 93% of participants; psychotropic medication was prescribed to 81 (45.8%) of them. Number of siblings showed a direct correlation with IQ, especially among males, and inappropriate speech was more intense in only-child females. Obesity was, in parallel, strongly associated with ascending age and with not being currently under growth hormone (GH) treatment. Participants taking any psychotropic medication were characterised by more frequent age ≥30 years, high level of hyperactivity and a psychiatric diagnosis.

CONCLUSIONS

Characterisation of persons with PWS in Spain confirms their physical and behavioural phenotype and supports the long-term application of GH therapy and the rational use of psychotropic medication.

Early psychomotor development and growth hormone therapy in children with Prader-Willi syndrome: a review

Prader-Willi syndrome (PWS) is a rare genetic disorder caused by the loss of imprinted gene expression on the paternal chromosome 15q11-q13. PWS is characterized by varying degrees of early psychomotor developmental deficits, primarily in cognition, language, and motor development. This review summarizes the early mental cognitive development, language development, and motor development in patients with PWS, compares the correlation of genotype with phenotype, and provides an update regarding the effects and concerns related to potential main side effects of treatment with recombinant human growth hormone on early psycho-cognitive and motor function development along with the linear growth and body composition of children with PWS.Conclusion: Early psychomotor development is strongly correlated with the prognosis of patients with PWS; moreover, current studies support that the initiation of interventions at an early age can exert significant beneficial effects on enhancing the cognitive and linguistic development of patients with PWS and allow them to "catch up" with motor development.  What is Known: • Prader-Willi syndrome is a rare genetic disorder characterized by multisystem damage, and children with Prader-Willi syndrome are typically characterized by early developmental delays, specifically in the areas of cognitive and motor development. • Recombinant human growth hormone therapy is the only medical treatment approved for Prader-Willi syndrome. What is New: • Extensive presentation of psycho-cognitive and motor development features and genotype-phenotype correlation in children with Prader-Willi syndrome.  • The effects of growth hormone on early psychomotor development in children with Prader-Willi syndrome were thoroughly reviewed, including their short- and long-term outcomes and any associated adverse effects.

The Pivotal Role of Oxytocin's Mechanism of Thermoregulation in Prader-Willi Syndrome, Schaaf-Yang Syndrome, and Autism Spectrum Disorder

Oxytocin (Oxt) regulates thermogenesis, and altered thermoregulation results in Prader-Willi syndrome (PWS), Schaaf-Yang syndrome (SYS), and Autism spectrum disorder (ASD). PWS is a genetic disorder caused by the deletion of the paternal allele of 15q11-q13, the maternal uniparental disomy of chromosome 15, or defects in the imprinting center of chromosome 15. PWS is characterized by hyperphagia, obesity, low skeletal muscle tone, and autism spectrum disorder (ASD). Oxt also increases muscle tonicity and decreases proteolysis while PWS infants are hypotonic and require assisted feeding in early infancy. This evidence inspired us to merge the results of almost 20 years of studies and formulate a new hypothesis according to which the disruption of Oxt's mechanism of thermoregulation manifests in PWS, SYS, and ASD through thermosensory abnormalities and skeletal muscle tone. This review will integrate the current literature with new updates on PWS, SYS, and ASD and the recent discoveries on Oxt's regulation of thermogenesis to advance the knowledge on these diseases.

Analysis of the Diet Quality and Nutritional State of Children, Youth, and Young Adults with Prader-Willi Syndrome: A Polish Multiple Case Study

Given the lack of data on dietary quality in young individuals with Prader-Willi syndrome (PWS) in Poland, a multiple case study was conducted in which anthropometric measurements and 7-day dietary records were collected from 20 subjects with PWS. The study group consisted of 8 females and 12 males with a mean age of 14.8 years and a mean BMI of 21.6. Based on BMI analysis, five subjects were overweight, including two subjects who were obese. The study showed that 35% of the subjects had energy intakes above the recommended levels. Protein deficiency was found in one subject in the analyzed diets. However, fat intake was excessive in four subjects, and the majority exceeded the recommended intake of saturated fatty acids. Vitamin E and B12 deficiencies were found in 40% and 85% of the subjects, respectively. All subjects had inadequate intakes of vitamin D and iodine, while the majority had deficiencies in sodium and copper intakes. Calcium intake was deficient in 35% of the subjects. However, most subjects met recommendations for the intakes of other minerals, vitamins, and fiber. These findings confirm the suboptimal dietary patterns of Polish individuals with PWS, with deficits observed in the intake of certain vitamins and minerals.

Metabolic and bariatric surgery for obesity in Prader Willi syndrome: systematic review and meta-analysis

Obesity is the leading cause of morbidity and mortality in patients with Prader-Willi Syndrome (PWS). Our objective was to compare changes in body mass index (BMI) after metabolic and bariatric surgery (MBS) for the treatment of obesity (BMI ≥35 kg/m2) in PWS. A systematic review of MBS in PWS was performed using PubMed, Embase, and Cochrane Central, identifying 254 citations. Sixty-seven patients from 22 articles met criteria for inclusion in the meta-analysis. Patients were organized into 3 groups: laparoscopic sleeve gastrectomy (LSG), gastric bypass (GB), and biliopancreatic diversion (BPD). No mortality within 1 year was reported in any of the 3 groups after a primary MBS operation. All groups experienced a significant decrease in BMI at 1 year with a mean reduction in BMI of 14.7 kg/m2 (P < .001). The LSG groups (n = 26) showed significant change from baseline in years 1, 2, and 3 (P value at year 3 = .002) but did not show significance in years 5, 7, and 10. The GB group (n = 10) showed a significant reduction in BMI of 12.1 kg/m2 in the first 2 years (P = .001). The BPD group (n = 28) had a significant reduction in BMI through 7 years with an average reduction of 10.7 kg/m2 (P = .02) at year 7. Individuals with PWS who underwent MBS had significant BMI reduction sustained in the LSG, GB, and BPD groups for 3, 2, and 7 years, respectively. No deaths within 1 year of these primary MBS operations were reported in this study or any other publication.

Long-term effects of GH therapy in adult patients with Prader-Willi syndrome: a longitudinal study

Introduction

Prader-Willi syndrome (PWS) is a complex disorder resulting from the failure of expression of paternal alleles in the PWS region of chromosome 15. The PWS phenotype resembles that observed in the classic non-PWS GH deficiency (GHD), including short stature, excessive fat mass, and reduced muscle mass. To date, a small number of studies on the long-term effects of GH treatment are available in adult subjects with PWS.

Methods

In this longitudinal study, 12 obese subjects with PWS (GHD/non-GHD 6/6) were treated for a median of 17 years, with a median GH dose of 0.35 mg/day. The median age was 27.1 years. Anthropometric, body composition, hormonal, biochemical, and blood pressure variables were analyzed in all subjects.

Results

Waist circumference was significantly lower at the end of the treatment period (p-value=0.0449), while body mass index (BMI) did not differ significantly. Compared to the baseline, a highly significant reduction of Fat Mass % (FM%) was observed (p-value=0.0005). IGF-I SDS values significantly increased during GH therapy (p-value=0.0005). A slight impairment of glucose homeostasis was observed after GH therapy, with an increase in the median fasting glucose levels, while insulin, HOMA-IR, and HbA1c values remained unchanged. Considering GH secretory status, both subjects with and without GHD showed a significant increase in IGF-I SDS and a reduction of FM% after GH therapy (p-value= 0.0313 for all).

Discussion

Our results indicate that long-term GH treatment has beneficial effects on body composition and body fat distribution in adults with PWS associated with obesity. However, the increase in glucose values during GH therapy should be considered, and continuous surveillance of glucose metabolism is mandatory during long-term GH therapy, especially in subjects with obesity.

Central precocious puberty in Prader-Willi syndrome: a narrative review

Prader-Willi syndrome (PWS, OMIM176270) is a rare genetic disorder with recognizable dysmorphic features and multisystemic consequences such as endocrine, neurocognitive and metabolic ones. Although most patients with Prader-Willi syndrome exhibit hypogonadotropic hypogonadism, there is variability regarding sexual maturation, with precocious puberty occurring in rare cases. Our aim is to elaborate a thorough review of Prader-Willi patients with central precocious puberty, in order to raise awareness of such cases and to enhance our knowledge regarding the diagnosis and prompt treatment of this particular PWS patients.

Early recombinant human growth hormone treatment improves mental development and alleviates deterioration of motor function in infants and young children with Prader-Willi syndrome

BACKGROUND

Recombinant human growth hormone (rhGH) therapy has shown to improve height and body composition in children with Prader-Willi syndrome (PWS), the evidence of early rhGH treatment on motor and mental development is still accumulating. This study explored the time effect on psychomotor development, anthropometric indexes, and safety for infants and young children with PWS.

METHODS

A phase 3, single-arm, multicenter, self-controlled study was conducted in six sites. Patients received rhGH at 0.5 mg/m2/day for first four weeks, and 1 mg/m2/day thereafter for up to 52 weeks. Motor development was measured using Peabody Developmental Motor Scales-second edition, mental development using Griffiths Development Scales-Chinese (GDS-C). Height standard deviation score (SDS), body weight SDS, and body mass index (BMI) SDS were also assessed.

RESULTS

Thirty-five patients were enrolled totally. Significant improvements were observed in height, body weight, and BMI SDS at week 52; GDS-C score showed significant improvement in general quotient (GQ) and sub-quotients. In a linear regression analysis, total motor quotient (TMQ), gross motor quotient (GMQ), and fine motor quotient were negatively correlated with age; however, treatment may attenuate deterioration of TMQ and GMQ. Changes in GQ and locomotor sub-quotient in < 9-month group were significantly higher than ≥ 9-month group. Mild to moderate severity adverse drug reactions were reported in six patients.

CONCLUSION

Fifty-two-week treatment with rhGH improved growth, BMI, mental development, and lessened the deterioration of motor function in infants and young children with PWS. Improved mental development was more pronounced when instituted in patients < 9 months old.

Evaluation of Autonomic Nervous System Dysfunction in Childhood Obesity and Prader-Willi Syndrome

The autonomic nervous system (ANS) may play a role in the distribution of body fat and the development of obesity and its complications. Features of individuals with Prader-Willi syndrome (PWS) impacted by PWS molecular genetic classes suggest alterations in ANS function; however, these have been rarely studied and presented with conflicting results. The aim of this study was to investigate if the ANS function is altered in PWS. In this case-control study, we assessed ANS function in 20 subjects with PWS (6 males/14 females; median age 10.5 years) and 27 body mass index (BMI) z-score-matched controls (19 males/8 females; median age 12.8 years). Standardized non-invasive measures of cardiac baroreflex function, heart rate, blood pressure, heart rate variability, quantitative sudomotor axon reflex tests, and a symptom questionnaire were completed. The increase in heart rate in response to head-up tilt testing was blunted (p < 0.01) in PWS compared to controls. Besides a lower heart rate ratio with Valsalva in PWS (p < 0.01), no significant differences were observed in other measures of cardiac function or sweat production. Findings suggest possible altered sympathetic function in PWS.

The influence of growth hormone on pediatric body composition: A systematic review

BACKGROUND

Growth hormone (GH) affects metabolism and regulates growth in childhood. The most prominent feature of GH deficiency (GHD) in children is diminished height velocity that eventually leads to short stature. In adult-onset GHD, lean body mass (LBM) is reduced, and visceral fat mass (FM) increased. Beneficial effects of GH treatment on body composition in adults with GHD, including an increase in muscle mass and a decrease in FM, are well established. Relatively few studies have investigated the effects of GH treatment on the body composition of pediatric patients with idiopathic or hypothalamic-pituitary disease-associated GH deficiency. This systematic review aimed to summarize available evidence relating to the effects of GH treatment on body composition in children with GHD.

METHODS

The PubMed, Science Direct, Cochrane Trials, and Embase databases, were searched with keywords including "GH", "body composition", "children", and "growth hormone" for English-language articles, published between January 1999 and March 2021. Two reviewers independently evaluated the search results and identified studies for inclusion based on the following criteria: participants had a confirmed diagnosis of GHD (as defined in each study); participants were pediatric patients who were receiving GH or had stopped GH treatment, regardless of whether they were pre- or post-pubertal; the intervention was recombinant human GH (rhGH; somatropin); and outcomes included changes in body composition during or after stopping GH therapy. Data extracted from each study included study quality, study sample characteristics, study interventions, and body composition. Data on fat-free mass and LBM were combined into a single category of LBM.

RESULTS

Sixteen studies reporting changes in body composition (i.e., FM and LBM) associated with GH treatment in children with GHD were identified and included in the review. Collectively, these studies demonstrated that FM decreased, and LBM increased in response to GH replacement therapy.

CONCLUSION

Despite study limitations (i.e., potential effects of diet and physical activity were not considered), we concluded that a periodic body composition assessment is required to ensure that a satisfactory body composition is achieved during GH replacement therapy in children with GHD.

Preserved Sleep for the Same Level of Respiratory Disturbance in Children with Prader-Willi Syndrome

Debate remains as to how to balance the use of recombinant human growth hormone (rhGH) as an important treatment in Prader-Willi syndrome (PWS) with its potential role in obstructive sleep apnea. This single-center, retrospective study assessed differences in overnight polysomnography results between children with and without PWS and changes in respiratory parameters before and after the initiation of rhGH treatment in those with PWS. Compared with age-, sex-, and body-mass-index-matched controls (n = 87), children with PWS (n = 29) had longer total sleep time (434 ± 72 vs. 365 ± 116 min; p < 0.01), higher sleep efficiency (86 ± 7 vs. 78 ± 15%; p < 0.05), and lower arousal events (8.1 ± 4.5 vs. 13.0 ± 8.9 events/h; p < 0.05). Mean oxygen saturation was lower in PWS children (94.3 ± 6.0 vs. 96.0 ± 2.0%; p < 0.05), with no other differences in respiratory parameters between groups. Eleven children with PWS (38%) met the criteria for further analyses of the impact of rhGH; polysomnography parameters did not change with treatment. Compared with other children undergoing polysomnography, children with PWS had more favorable markers of sleep continuity and lower oxygen saturation for the same level of respiratory disturbance. rhGH administration was not associated with changes in respiratory parameters in PWS.

Cognitive Phenotype and Psychopathology in Noonan Syndrome Spectrum Disorders through Various Ras/MAPK Pathway Associated Gene Variants

Cognitive difficulties are argued to be common in patients with Noonan syndrome spectrum disorders (NSSDs), but findings are based on studies in which patients with variants in PTPN11 (prevalence ~50%) were overrepresented. The current study, using a structured clinical approach, describes the cognitive phenotype and psychopathology of 100 patients (aged 6 to 61 years) with nine different gene variants in the Ras/MAPK pathway underlying NSSDs (PTPN11n = 61, PTPN11 Noonan syndrome with multiple lentigines n = 3, SOS1n = 14, KRASn = 7, LZTR1n = 5, RAF1n = 4, SHOC2n = 2, CBLn = 2, SOS2n = 2). After weighted assessment and bootstrapping of the results of individual neuropsychological assessments and measures of psychopathology, cognitive performances in most variant groups were within the ranges of expectation. IQs were significantly lower in patients with variants in PTPN11, KRAS, RAF1, and SHOC2, but no specific cognitive impairments were found. The performances of younger participants (<16 years of age) did not differ from those of adults. Alexithymia and internalizing problems were more frequent in patients with variants in PTPN11 and SOS1, while PTPN11 patients also showed higher levels of externalizing problems. These results stress the need to take intelligence into account when interpreting lower cognitive performances in individual neuropsychological assessments, which is crucial for an adequate understanding and guidance of patients with NSSDs.

Subcutaneous adipose tissue is a positive predictor for bone mineral density in prepubertal children with Prader-Willi syndrome independent of lean mass

OBJECTIVES

Emerging evidence suggests a fat depot-specific relationship with bone mineral density (BMD) in children, particularly in those who are overweight/obese. However, this has not yet been investigated in detail in children with Prader-Willi syndrome (PWS), a genetic syndrome characterized by a decreased lean mass (LM) and increased fat mass (FM). The objective of this study is to investigate the relationships of LM and FM, particularly fat distribution, with bone mineral parameters.

METHODS

This is a retrospective and cross-sectional study. Forty-seven prepubertal Japanese children with PWS (22 males, mean age: 6.86 years) were included. No subjects had type 2 diabetes mellitus or osteoporotic medications. LM, FM, and BMD and bone mineral content in the total body less head and the lumbar spine were measured using dual-energy x-ray absorptiometry, in addition to subcutaneous/visceral adipose tissue (SAT/VAT), and the ratio of VAT to SAT (V/S) by computed tomography at the umbilical level. Bone mineral apparent density was calculated to correct for bone size.

RESULTS

LM positively correlated with bone mineral parameters after controlling for age, sex, growth hormone (GH) treatment, and FM. Although FM did not correlate with bone mineral parameters, compartment-specific analysis revealed that SAT positively and V/S negatively correlated with bone mineral parameters after controlling for age, sex, GH treatment and LM.

CONCLUSIONS

A compartment-specific effect of FM on bone mineral parameters was noted such that SAT was a positive predictor for BMD independent of LM in prepubertal children with PWS.

Endocrine and Metabolic Illnesses in Young Adults with Prader-Willi Syndrome

Prader−Willi syndrome (PWS) is a rare genetic disorder characterized by an insatiable appetite that leads to morbid obesity. Previous studies reported health problems in adults with PWS. However, studies on younger adults are lacking, and there are no specific studies of endocrine and metabolic illness in this age group. We performed a retrospective cohort study of 68 individuals with PWS aged 19 to 34 years at Samsung Medical Center. The prevalence of endocrine and metabolic illnesses were compared with those in an age-, sex-, and BMI-matched healthy control group. Young adults with PWS had a higher prevalence of metabolic syndrome (35.3% vs. 4.4%), type 2 diabetes mellitus (50.0% vs. 5.4%), hypertension (30.8% vs. 16.1%), dyslipidemia (38.2% vs. 14.7%), decreased bone density (26.4% vs. 0.9%), and sleep apnea (32.3% vs. 4.4%) than controls (all p < 0.05). The PWS group that maintained recombinant human growth (rhGH) treatment in adulthood had a lower probability of having a BMI ≥ 30 at the last follow-up (odds ratio = 0.106 (0.012−0.948), p = 0.045). Endocrine and metabolic illnesses in individuals with PWS may have already started in the early teens; therefore, appropriate screening and early intervention are important. Better understanding of the natural history of PWS and age-related complications will lead to better-quality medical care for individuals with PWS.

Hypothalamic syndrome

Hypothalamic syndrome (HS) is a rare disorder caused by disease-related and/or treatment-related injury to the hypothalamus, most commonly associated with rare, non-cancerous parasellar masses, such as craniopharyngiomas, germ cell tumours, gliomas, cysts of Rathke's pouch and Langerhans cell histiocytosis, as well as with genetic neurodevelopmental syndromes, such as Prader-Willi syndrome and septo-optic dysplasia. HS is characterized by intractable weight gain associated with severe morbid obesity, multiple endocrine abnormalities and memory impairment, attention deficit and reduced impulse control as well as increased risk of cardiovascular and metabolic disorders. Currently, there is no cure for this condition but treatments for general obesity are often used in patients with HS, including surgery, medication and counselling. However, these are mostly ineffective and no medications that are specifically approved for the treatment of HS are available. Specific challenges in HS are because the syndrome represents an adverse effect of different diseases, and that diagnostic criteria, aetiology, pathogenesis and management of HS are not completely defined.

Circulating insulin-like growth factor 1 levels are reduced in very young children with Prader-Willi syndrome independent of anthropometric parameters and nutritional status

OBJECTIVE

Insulin growth factor-1 (IGF-1) is used to evaluate growth hormone (GH) sufficiency and is decreased in children with Prader-Willi syndrome (PWS). Although IGF-1 is negatively affected by body size and nutritional status, both of which are impaired in PWS children, these variables are typically not considered when assessing IGF-1 levels in these subjects. Here, we compared IGF-1 levels in PWS children to controls matched for age, sex, anthropometric parameters, and nutritional status.

DESIGN/PATIENTS/MEASUREMENTS

The retrospective analysis included genetically diagnosed PWS subjects (n = 65, median age; 14.0 months) and controls (n = 111, 14.3 months) matched for age, sex, anthropometric parameters (height-standard deviation score [SDS], weight-SDS, body mass index-SDS), and serum albumin levels, a marker for nutritional status. IGF-1 SDS was compared between PWS subjects and controls after adjustment for confounding variables. The GH provocation test was performed in 29 PWS subjects, and IGF-1 SDS was compared between GH-sufficient (n = 20) and GH-deficient (n = 9) subjects. Spearman's rank correlation coefficient was performed to investigate the association between age and IGF-1 SDS. None had received GH or levothyroxine treatment.

RESULTS

After adjustment for confounding variables, IGF-1 SDS was significantly lower in PWS subjects than controls (-1.56 vs. -1.01, p = .003), while it was not different between GH-sufficient and GH-deficient PWS subjects. Correlation analysis failed to show an association between age and IGF-1 SDS both in control and PWS groups.

CONCLUSIONS

IGF-1 SDS is lower in very young children with PWS independent of anthropometric parameters and nutritional status, suggesting the presence of hypothalamic dysfunction of GH secretion.

Approach to the Patient: Safety of Growth Hormone Replacement in Children and Adolescents

The use of recombinant human growth hormone (rhGH) in children and adolescents has expanded since its initial approval to treat patients with severe GH deficiency (GHD) in 1985. rhGH is now approved to treat several conditions associated with poor growth and short stature. Recent studies have raised concerns that treatment during childhood may affect morbidity and mortality in adulthood, with specific controversies over cancer risk and cerebrovascular events. We will review 3 common referrals to a pediatric endocrinology clinic, followed by a summary of short- and long-term effects of rhGH beyond height outcomes. Methods to mitigate risk will be reviewed. Finally, this information will be applied to each clinical case, highlighting differences in counseling and clinical outcomes. rhGH therapy has been used for more than 3 decades. Data are largely reassuring, yet we still have much to learn about pharmaceutical approaches to growth in children and the lifelong effect of treatment.

The Year in Growth and Short Stature

The papers and communications selected here, published in 2020-2021, report major advances in pathophysiology, diagnostics, treatment and patient care in the fields of growth hormones and disorders. © 2022 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.

Adrenal insufficiency in patients with Prader-Willi syndrome

The generalized dysfunction of the hypothalamic-pituitary axis in patients with Prader-Willi syndrome (PWS) is the most likely cause of hypogonadism, inadequate growth hormone secretion, excessive appetite and associated obesity, impaired body temperature regulation, and hypothyroidism. The syndrome is also related to an increased risk of central adrenal insufficiency, although its prevalence remains unknown. The results of the studies in which different methods of pharmacological stimulation were used do not provide conclusive outcomes. As a result, there are no clear guidelines with regard to diagnosis, prevention, or long-term care when adrenal insufficiency is suspected in patients with PWS. Currently, most patients with PWS are treated with recombinant human growth hormone (rhGH). It has been confirmed that rhGH therapy has a positive effect on growth, body composition, body mass index (BMI), and potentially on psychomotor development in children with PWS. Additionally, rhGH may reduce the conversion of cortisone to cortisol through inhibition of 11β-hydroxysteroid dehydrogenase type 1. However, its influence on basal adrenal function and adrenal stress response remains unexplained in children with PWS. This paper reviews the literature related to the hypothalamic-pituitary-adrenal axis dysfunction in the PWS patient population with a focus on children.

Management of Prader-Labhart-Willi syndrome in children and in adults, with particular emphasis on the treatment with recombinant human growth hormone

INTRODUCTION

Prader-Willi syndrome (PWS) is a genetically determined disease that manifests itself in a number of abnormalities resulting, among others, from dysfunction of the hypothalamic-pituitary system. Only integrated, multidisciplinary care gives patients the chance to significantly improve the quality of life and achieve a life expectancy that does not differ from the general population.

AIM

The aim of the study was to summarize the available literature on the management of patients suffering from PWS.

CONCLUSIONS

More and more reports based on clinical trials conducted around the world indicate the undeniable benefits of rhGH therapy in patients with PWS in childhood and after the end of growth period. They consist in improving the body composition, improving the lipid profile, increasing bone mineral density and improving the mental state and patients' quality of life.

Health Problems in Individuals With PWS Are Associated With Lower Quality of Life for Their Parents: A Snapshot in the Brazilian Population

Prader-Willi syndrome (PWS) is a complex genetic disorder requiring interdisciplinary team monitoring and intensive care by parents. So far there is little information on people with PWS in Brazil. Our aim was to describe health problems and treatments used by people with PWS in Brazil and their relationship to their parents' quality of life. Parents answered questionnaires about their child's medical and exercise history, behavior problems, sociodemographic characteristics, and their own quality of life. Results: The responses of the participants showed similar health problems as in other countries. Anxiety and tantrums were the behavioral problems most commonly cited by parents. Parents of people with PWS had lower scores in respect of quality of life than the Brazilian population. Behavioral problems in individuals with PWS were negatively associated with their parents' quality of life. Behavioral and medical conditions in the children were associated with reduced quality of life in the parents. We conclude that heath care should not only be directed toward those with PWS, but also their parents.

Diabetes Mellitus in Prader-Willi Syndrome: Natural History during the Transition from Childhood to Adulthood in a Cohort of 39 Patients

Type 2 diabetes mellitus (T2DM) affects 20% of patients with Prader-Willi syndrome (PWS), with many cases diagnosed during the transition period. Our aim was to describe the natural history of T2DM in patients with PWS before the age of 25 years and to develop screening and preventive strategies. Thirty-nine patients followed in the French PWS Reference Center were included (median age 25.6 years [23.7; 31.7]). Twenty-one had been treated with growth hormone (GH), fifteen had not, and three had an unknown status. The median age at T2DM diagnosis was 16.8 years (11–24) and the median BMI was 39 kg/m² [34.6; 45], with 34/35 patients living with obesity. The patients displayed frequent psychiatric (48.3% hospitalization,) and metabolic (56.4% hypertriglyceridemia,) comorbidities and a parental history of T2DM (35.7%) or overweight (53.6%) compared to the PWS general population. There was no difference in BMI and metabolic complications between the GH-treated and non-GH-treated groups at T2DM diagnosis. Patients with PWS who develop early T2DM have severe obesity, a high frequency of psychiatric and metabolic disorders, and a family history of T2DM and overweight. These results underline the need for early identification of patients at risk, prevention of obesity, and repeated blood glucose monitoring during the transition period.

Effects of COVID-19 Lockdown on Weight, Body Composition, and Behavior of Children, Adolescents, and Young Adults with Prader-Willi Syndrome

To reduce transmission of the coronavirus disease 2019 (COVID-19), many countries implemented lockdowns, causing the closure of childcare services. This study was designed to evaluate the impact of the COVID-19 lockdown in March-April 2020 on children, adolescents, and young adults with Prader-Willi syndrome (PWS) living in Germany. We recruited 180 participants with a genetically confirmed PWS. All families completed a questionnaire, and participants underwent a post-lockdown assessment; the last examination before the lockdown was determined as the pre-lockdown assessment. We used bivariate analyses to compare pre- and post-lockdown outcomes. Weight standard deviation scores (SDS_PWS) and body mass index (BMI)-SDS_PWS remained stable or even decreased in some age groups. A statistically significant gain in lean body mass (LBM) was found in all groups <18 years of age. We observed an increase in IGF-I and IGFBP-3 concentrations without a significant change in growth hormone (GH) dosage. Most families (95.4%) reported set mealtimes and implementation of structured activities (72.2%) during the lockdown period. We therefore suggest that the favorable development of weight/BMI and LBM was caused by an interplay of a suspected enhanced GH administration and continuous parental commitment. However, more intense behavioral problems were observed in 45.7%, which persisted post-lockdown in 33.7%.

Growth Hormone Treatment for Adults With Prader-Willi Syndrome: A Meta-Analysis

CONTEXT

Features of Prader-Willi syndrome (PWS) overlap with features of growth hormone (GH) deficiency, like small hands and feet, short stature, increased body fat, and low muscle mass and strength. In children with PWS, GH treatment (GHt) improves physical health and cognition. GHt has become the standard of care in PWS children, but in adults this is not yet the case.

OBJECTIVE

This work aims to provide an overview of the current knowledge on GHt in PWS adults.

METHODS

Medline, Embase, and the Cochrane Central Register of Controlled Trials databases were searched. Study selection included randomized clinical trials (RCTs) and nonrandomized (un)controlled trials (NRCTs) that reported data for adults with PWS, who received GHt for at least 6 months. Data on body composition, body mass index (BMI), cardiovascular end points, bone, cognitive function, quality of life, and safety were extracted.

RESULTS

Nine RCTs and 20 NRCTs were included. Body composition improved during 12 months of GHt with an increase in mean (95% CI) lean body mass of 1.95 kg (0.04 to 3.87 kg) and a reduction of mean (95% CI) fat mass of -2.23% (-4.10% to -0.36%). BMI, low-density lipoprotein cholesterol levels, fasting glucose levels, and bone mineral density did not change during GHt. There were no major safety issues.

CONCLUSION

GHt appears to be safe and improves body composition in adults with PWS. Because poor body composition is closely linked to the observed high incidence of cardiovascular morbidity in adults with PWS, improving body composition might reduce cardiovascular complications in this vulnerable patient group.

Associations Between Hyperphagia, Symptoms of Sleep Breathing Disorder, Behaviour Difficulties and Caregiver Well-Being in Prader-Willi Syndrome: A Preliminary Study

Prader-Willi syndrome (PWS) is a rare genetic disorder characterised by neurodevelopmental delays, hyperphagia, difficulties with social communication and challenging behaviours. Individuals require intensive supervision from caregivers which may negatively affect caregiver quality of life. This study used data collected in the Australasian PWS Registry (n = 50, mean age 11.2 years) to evaluate associations between child behaviours and caregiver mental well-being. Symptoms of sleep-related breathing disorder, child depression and social difficulties were associated with poorer caregiver mental and physical well-being. Growth hormone therapy use was associated with better caregiver mental and physical well-being. Optimising management of problematic behaviours and sleep disturbances have the potential to support caregivers who are the most vital network of support for individuals affected by PWS.

[Clinical guidelines «Obesity in children»]

Childhood obesity is an urgent problem of pediatric endocrinology due to the widespread occurrence, the development of metabolic complications and their steady tracking into adulthood. The developed clinical guidelines are the main working tool of the practitioner. They briefly and structurally present the main information about the epidemiology and modern classification of obesity, methods of its diagnosis and treatment based on the principles of evidence-based medicine.

Effects of Childhood Multidisciplinary Care and Growth Hormone Treatment on Health Problems in Adults with Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a complex hypothalamic disorder. Features of PWS include hyperphagia, hypotonia, intellectual disability, and pituitary hormone deficiencies. The combination of growth hormone treatment and multidisciplinary care (GHMDc) has greatly improved the health of children with PWS. Little is known about the effects of childhood GHMDc on health outcomes in adulthood. We retrospectively collected clinical data of 109 adults with PWS. Thirty-nine had received GHMDc during childhood and adolescence (GHMDc+ group) and sixty-three had never received growth hormone treatment (GHt) nor multidisciplinary care (GHMDc− group). Our systematic screening revealed fewer undetected health problems in the GHMDc+ group (10%) than in the GHMDc− group (84%). All health problems revealed in the GHMDc+ group had developed between the last visit to the paediatric and the first visit to the adult clinic and/or did not require treatment. Mean BMI and the prevalence of diabetes mellitus type 2 were significantly lower in the GHMDc+ group compared to the GHMDc− group. As all patients who received GHt were treated in a multidisciplinary setting, it is unknown which effects are the result of GHt and which are the result of multidisciplinary care. However, our data clearly show that the combination of both has beneficial effects. Therefore, we recommend continuing GHMDc after patients with PWS have reached adult age.

Effects of Recombinant Human Growth Hormone Treatment, Depending on the Therapy Start in Different Nutritional Phases in Paediatric Patients with Prader-Willi Syndrome: A Polish Multicentre Study

Recombinant human growth hormone (rhGH) treatment is an established management in patients with Prader-Willi syndrome (PWS), with growth promotion and improvement in body composition and possibly the metabolic state. We compared anthropometric characteristics, insulin-like growth factor 1 (IGF1) levels, metabolic parameters and the bone age/chronological age index (BA/CA) in 147 children with PWS, divided according to age of rhGH start into four groups, corresponding to nutritional phases in PWS. We analysed four time points: baseline, rhGH1 (1.21 ± 0.81 years), rhGH2 (3.77 ± 2.17 years) and rhGH3 (6.50 ± 2.92 years). There were no major differences regarding height SDS between the groups, with a higher growth velocity (GV) (p = 0.00) and lower body mass index (BMI) SDS (p < 0.05) between the first and older groups during almost the whole follow-up. IGF1 SDS values were lower in group 1 vs. other groups at rhGH1 and vs. groups 2 and 3 at rhGH2 (p < 0.05). Glucose metabolism parameters were favourable in groups 1 and 2, and the lipid profile was comparable in all groups. BA/CA was similar between the older groups. rhGH therapy was most effective in the youngest patients, before the nutritional phase of increased appetite. We did not observe worsening of metabolic parameters or BA/CA advancement in older patients during a comparable time of rhGH therapy.

Prader-Willi syndrome: Hormone therapies

Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder linked to the lack of expression of specific maternally imprinted genes located in the chromosomal region 15q11-q13. Impaired hypothalamic development and function explain most of the phenotype that is characterized by a specific trajectory from anorexia at birth to excessive weight gain at later ages, which is accompanied by hyperphagia and early severe obesity, as well as by other hormonal deficiencies, behavioral deficits, and dysautonomia. In almost all patients, their endocrine dysfunction involves growth hormone deficiency and hypogonadism, which originate from a combination of both peripheral and hypothalamic origin, central hypothyroidism in 40%, precocious adrenarche in 30% of the cases, and in rare cases, also adrenocorticotropin deficiency and precocious puberty. In addition, the oxytocin (OXT) and ghrelin systems are impaired in most patients and involved in a poor suckling response at birth, and hyperphagia with food addiction, poor social skills, and emotional dysregulation. Current hormonal replacement treatments are the same as used in classical hormonal deficiencies, and recombinant human GH treatment is registered since 2000 and has dramatically changed the phenotype of these children. OXT and OXT analogue treatments are currently investigated as well as new molecules targeting the ghrelin system. The severe condition of PWS can be seen as a model to improve the fine description and treatments of hypothalamic dysfunction.

A retrospective analysis of growth hormone therapy in children with Schaaf-Yang syndrome

Short stature is a common phenotype in children with Schaaf-Yang syndrome (SYS). Prader-Willi syndrome (PWS) and SYS share several phenotypic features including short stature, muscular hypotonia and developmental delay/intellectual disability. Evidence exists that similar to PWS, growth hormone (GH) deficiency may also be a feature of SYS. Recombinant human GH (rhGH) therapy has been approved for PWS, but the effects of rhGH therapy in individuals with SYS have not yet been documented. This retrospective, questionnaire-based study analyzes the prevalence of rhGH therapy in children with SYS, the effects of rhGH therapy on anthropometric measures, and parental perception of the treatment. Twenty-six individuals with SYS were sent a clinical questionnaire and a request for growth charts. We found a significant increase in height z-score (p* = 0.04) as well as a significant decrease in body mass index 6 months after rhGH therapy initiation (p* = 0.04). Furthermore, height z-scores of the treated group (mean z-score = -1.00) were significantly higher than those of the untreated group (mean z-score = -3.36, p = 0.01) at time of enrollment. All parents reported an increase in muscle strength and endurance, and several families noted beneficial effects such as improved cognition and motor development.

Endocrine disorders in Prader-Willi syndrome: a model to understand and treat hypothalamic dysfunction

Prader-Willi syndrome is a rare genetic neurodevelopmental disorder resulting from the loss of expression of maternally imprinted genes located in the paternal chromosomal region, 15q11-13. Impaired hypothalamic development and function is the cause of most of the phenotypes comprising the developmental trajectory of Prader-Willi syndrome: from anorexia at birth to excessive weight gain preceding hyperphagia, and early severe obesity with hormonal deficiencies, behavioural problems, and dysautonomia. Growth hormone deficiency, hypogonadism, hypothyroidism, premature adrenarche, corticotropin deficiency, precocious puberty, and glucose metabolism disorders are the main endocrine dysfunctions observed. Additionally, as a result of hypothalamic dysfunction, oxytocin and ghrelin systems are impaired in most patients. Standard pituitary and gonadal hormone replacement therapies are required. In this Review, we discuss Prader-Willi syndrome as a model of hypothalamic dysfunction, and provide a comprehensive description of the accumulated knowledge on genetics, pathophysiology, and treatment approaches of this rare disorder.

Dietary Management for Adolescents with Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a complex, multisystem neurodevelopmental disorder affecting approximately 1 in 25,000 live births. PWS is caused by absence of expression of paternally inherited imprinted genes on chromosome 15q11-q13. The syndrome typically occurs due to one of three genetic mechanisms: paternal deletion of involved genes, maternal uniparental disomy, or imprinting center defects. These genetic anomalies lead to well-described clinical phenotype that includes hypotonia, hypothalamic dysfunction, social and behavioral issues, life-threatening hyperphagia, and elevated probability of obesity. Adolescents with PWS are at the highest risk for development of life-threatening obesity due to increased access to food, decreased physical activity, and hyperphagia. Currently, the only treatment for the hyperphagia is environmental control, including locked kitchens and continuous supervision of the affected individual. Caloric intake must be restricted to prevent obesity, which subsequently increases the hunger drive even more. Research and clinical practice have demonstrated that increasing physical activity along with insuring a well-balanced, nutritionally dense diet can improve overall weight control in adolescents with PWS.