Cognitive, emotional, physical and social effects of growth hormone treatment in adults with Prader-Willi syndrome

Case report: Long-term efficacy and safety of semaglutide in the treatment of syndromic obesity in Prader Willi syndrome - case series and literature review

Introduction

Prader-Willi syndrome (PWS) is the most prevalent cause of syndromic obesity. Obesity development in PWS is driven by dysfunction in neural pathways involved in satiety and reward, dysregulation in hormones regulating satiety and food intake, altered body composition and reduced energy expenditure, as well as the presence of various hormone deficiencies. As hyperphagia, satiety dysfunction and consequent food-seeking behaviors are intrinsic to PWS, obesity management can be challenging.

Case series

We present a long-term follow-up of treatment with GLP-1 receptor agonist (GLP-1 RA) semaglutide in three patients with PWS without diabetes, one of whom had previously undergone metabolic surgery. Semaglutide treatment at dosages from 0.5 mg to 2 mg weekly demonstrated variable efficacy, from preventing further weight gain in patient 1, to achieving weight loss of up to 14.4% and 11% relative to baseline, in Patient 2 and Patient 3. It was well tolerated, even after metabolic surgery.

Conclusion

Long-term randomized placebo-controlled trials with larger sample sizes are needed to provide stronger evidence on the long-term efficacy and safety of semaglutide for obesity treatment in PWS as well as explore the potential synergistic effects of GLP-1 RA treatment combined with other therapeutic interventions.

Prostate-specific antigen (PSA) levels in men with Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a rare genetic disorder typically characterized by body composition abnormalities, hyperphagia, behavioral challenges, cognitive dysfunction, and hormone deficiencies. Hypogonadism is common but knowledge on potential side effects of testosterone replacement is limited, in particular, the long-term effects on behavior and PSA.

PATIENTS AND METHODS

Retrospective case studies of seven men, median age 46 years, with genetically verified PWS, testosterone treated hypogonadism and available PSA values were included. Long-term follow-up of PSA was accessible in four patients. Medical records were reviewed for adverse effects.

RESULTS

Five men were treated with intramuscular testosterone undecanoate, two had no hypogonadism. Median PSA was 0.68 μg/L (0.23-1.3), median testosterone 15 nmol/L. After a median time of 17 years of testosterone replacement median PSA was 0.75 μg/L (range 0.46-1.4). Testosterone replacement was well tolerated, and no major behavioral changes were reported. Five were treated with growth hormone for >20 years.

CONCLUSION

Levels of PSA were low. Long-term treatment with testosterone was working well and did not result in any clinically meaningful increase in PSA. Our results indicate that testosterone replacement is neither associated with serious adverse events regarding changes in behavior or effect on PSA. However, larger studies are needed to confirm our results.

Response to growth hormone therapy in ring chromosome 15: Review and evidence from a new case on possible beneficial effect in neurodevelopment

Type 1 Insulin-like Growth Factor Receptor(IGF1R) plays a fundamental role in normal growth and development. Its disruption is usually characterized by severe intrauterine and postnatal growth retardation, microcephaly and neurodevelopmental delay.The efficacy of recombinant human growth hormone treatment remains a challenge for children with IGF1 resistance and pathogenic mutations of IGF1R, with limited data in patients carrying the most severe form of IGF1R defect, the ring chromosome 15.

SUBJECT AND METHOD

We tested a high dose of rhGH in a new patient with ring chromosome 15, as confirmed by karyotype and CGH array. We performed a systematic review, and all published r(15) syndrome cases treated by growth hormone(GH) up to April 2023 were searched, and their response to GH therapy was recorded and summarized.

RESULTS

Twelve patients with ring chromosome 15 received GH therapy according to a literature review. We expand the spectrum by the 13th case treated by GH, and we report an impressive improvement in intellectual performance and progressive catch-up growth after 5 and 20 months of follow-up. By introducing our new case in the analysis, the sex ratio was 3:10, and GH therapy was started at the age of 5.5 (3/9.4) (years) for an age of diagnosis of 4.75 (1.3/9.5) (years). The height before GH therapy was -5.1(-5.9/-4.1) SDS. The median duration of treatment was 1.7(0.9/2) (years), with a median height gain of 1(0.3/1.8) SDS and an improvement in growth velocity of 4.1(2.8/5.3) (cm/year).

CONCLUSION

GH seems to be effective for r(15) syndrome patients with short stature.

Premature adrenarche in Prader-Willi syndrome is associated with accelerated pre-pubertal growth and advanced bone age

OBJECTIVES

Prader-Willi syndrome (PWS) is characterized by obesity, growth hormone deficiency, hypogonadism, and a high prevalence of premature adrenarche despite reported hypothalamic-pituitary-adrenal axis dysfunction. While idiopathic premature adrenarche is associated with accelerated pre-pubertal growth and advanced bone age, the consequences of elevated adrenal androgens on growth and bone maturation in PWS remain unknown. This study therefore sought to describe age-related changes in dehydroepiandrosterone sulfate (DHEAS) and their effects on growth and bone maturation in PWS.

METHODS

This retrospective observational study included 62 children with PWS. Simple and multiple regression models were constructed to relate age and BMI-SDS with DHEAS levels. Height velocity was compared to age and sex-based norms with t-tests and two-way ANOVA. Patterns in bone age Z-score were examined with two-way ANOVA, and the contributions of age, BMI-SDS, and DHEAS to bone age Z-score were analyzed with multiple regression.

RESULTS

DHEAS levels rose earlier and were less strongly correlated with age in males and females with PWS (R²=0.12 and 0.30) compared to healthy controls (R²=0.89 and 0.88) in a pattern unrelated to BMI-SDS (adjusted R²=0.076, p=0.10 for age, and 0.29 for BMI-SDS). Mid-childhood height velocity was increased in males and preserved in females with PWS before declining at the age of expected puberty (p<0.0001). Peri-adrenarchal bone age was advanced in a manner associated with DHEAS but not BMI-SDS (p<0.0001; adjusted R²=0.48, p=0.0014 for DHEAS, and 0.78 for BMI-SDS).

CONCLUSIONS

An obesity-independent increase in adrenal androgens is associated with accelerated mid-childhood growth and bone maturation in PWS.

Endocrine and behavioural features of Lowe syndrome and their potential molecular mechanisms

BACKGROUND

Lowe syndrome (LS) is an X linked disease caused by pathogenic variants in the OCRL gene that impacts approximately 1 in 500 000 children. Classic features include congenital cataract, cognitive/behavioural impairment and renal tubulopathy.

METHODS

This study is a retrospective review of clinical features reported by family based survey conducted by Lowe Syndrome Association. Frequency of non-ocular clinical feature(s) of LS and their age of onset was summarised. An LS-specific therapy effectiveness scale was used to assess the response to the administered treatment. Expression of OCRL and relevant neuropeptides was measured in postmortem human brain by qPCR. Gene expression in the mouse brain was determined by reanalysis of publicly available bulk and single cell RNA sequencing.

RESULTS

A total of 137 individuals (1 female, 89.1% white, median age 14 years (range 0.8-56)) were included in the study. Short stature (height <3rd percentile) was noted in 81% (n=111) individuals, and 15% (n=20) received growth hormone therapy. Undescended testis was reported in 47% (n=64), and median age of onset of puberty was 15 years. Additional features were dental problems (n=77, 56%), bone fractures (n=63, 46%), hypophosphataemia (n=60, 44%), developmental delay and behavioural issues. OCRL is expressed in human and mouse hypothalami, and in hypothalamic cell clusters expressing Ghrh, Sst, Oxt, Pomc and pituitary cells expressing Gh and Prl.

CONCLUSIONS

There is a wide spectrum of the clinical phenotype of LS. Some of the features may be partly driven by the loss of function of OCRL in the hypothalamus and the pituitary.

Recommendations for the diagnosis and management of childhood Prader-Willi syndrome in China

Prader-Willi syndrome (PWS) is a complex and multisystem neurobehavioral disease, which is caused by the lack of expression of paternally inherited imprinted genes on chromosome15q11.2-q13.1. The clinical manifestations of PWS vary with age. It is characterized by severe hypotonia with poor suck and feeding difficulties in the early infancy, followed by overeating in late infancy or early childhood and progressive development of morbid obesity unless the diet is externally controlled. Compared to Western PWS patients, Chinese patients have a higher ratio of deletion type. Although some rare disease networks, including PWS Cooperation Group of Rare Diseases Branch of Chinese Pediatric Society, Zhejiang Expert Group for PWS, were established recently, misdiagnosis, missed diagnosis and inappropriate intervention were usually noted in China. Therefore, there is an urgent need for an integrated multidisciplinary approach to facilitate early diagnosis and optimize management to improve quality of life, prevent complications, and prolong life expectancy. Our purpose is to evaluate the current literature and evidences on diagnosis and management of PWS in order to provide evidence-based guidelines for this disease, specially from China.

A Review of Prader–Willi Syndrome

Prader–Willi Syndrome (PWS, OMIM #176270) is a rare complex genetic disorder due to the loss of expression of paternally derived genes in the PWS critical region on chromosome 15q11-q13. It affects multiple neuroendocrine systems and may present failure to thrive in infancy, but then, hyperphagia and morbid obesity starting in early childhood became the hallmark of this condition. Short stature, hypogonadism, sleep abnormalities, intellectual disability, and behavioral disturbances highlight the main features of this syndrome. There have been a significant number of advances in our understanding of the genetic mechanisms underlying the disease, especially discoveries of MAGEL2, NDN, MKRN3, and SNORD116 genes in the pathophysiology of PWS. However, early diagnosis and difficulty in treating some of the disease’s most disabling features remain challenging. As our understanding of PWS continues to grow, so does the availability of new therapies and management strategies available to clinicians and families.

Neurobehavioral Dimensions of Prader Willi Syndrome: Relationships Between Sleep and Psychosis-Risk Symptoms

Background

Prader Willi Syndrome (PWS) is a genetic disorder caused by the absence of expression of the paternal copies of maternally imprinted gene(s) located at 15q11-q13. While the physical and medical characteristics of PWS, including short stature, hyperphagia and endocrine dysfunction are well-characterized, systematic investigation of the long-recognized psychiatric manifestations has been recent.

Methods

Here, we report on the first remote (web-based) assessment of neurobehavioral traits, including psychosis-risk symptoms (Prodromal Questionnaire-Brief Version; PQ-B) and sleep behaviors (Pittsburgh Sleep Quality Index), in a cohort of 128 participants with PWS, of whom 48% had a paternal deletion, 36% uniparental disomy, 2.4% an imprinting mutation and 13% unknown mutation (mean age 19.3 years ± 8.4; 53.9% female). We aimed to identify the most informative variables that contribute to psychosis-risk symptoms. Multiple domains of cognition (accuracy and speed) were also assessed in a subset of PWS participants (n = 39) using the Penn Computerized Neurocognitive Battery (Penn-CNB).

Results

Individuals with PWS reported a range of psychosis-risk symptoms, with over half reporting cognitive disorganization (63.1%) and about one third reporting unusual beliefs (38.6%) and/or suspiciousness (33.3%). Subjectively-reported sleep quality, nap frequency, sleep duration, sleep disturbance, and daytime dysfunction were significant predictors of psychosis-risk symptom frequency and severity (all p's < 0.029). Sleep disturbance ratings were the strongest predictors of psychosis-risk symptoms. Regarding cognition, individuals with PWS showed the most prominent deficits in accuracy on measures of social cognition involving faces, namely Face Memory, Age Differentiation and Emotion Recognition, and greatest slowing on measures of Attention and Emotion Recognition. However, there were no significant differences in psychosis-risk symptoms or cognitive performance as a function of PWS genetic subtype.

Conclusions

PWS is associated with a high prevalence of distressing psychosis-risk symptoms, which are associated with sleep disturbance. Findings indicate that self/parent-reported neurobehavioral symptoms and cognition can be assessed remotely in individuals with PWS, which has implications for future large-scale investigations of rare neurogenetic disorders.

One Year of Recombinant Human Growth Hormone Treatment in Adults with Prader-Willi Syndrome Improves Body Composition, Motor Skills and Brain Functional Activity in the Cerebellum

We compared body composition, biochemical parameters, motor function, and brain neural activation in 27 adults with Prader-Willi syndrome and growth-hormone deficiency versus age-and sex-matched controls and baseline versus posttreatment values of these parameters after one year of recombinant human growth hormone (rhGH) treatment. To study body composition, we analyzed percentage of fat mass, percentage of lean mass, and muscle-mass surrogate variables from dual X-ray absorptiometry. Biochemical parameters analyzed included IGF-I, glucose metabolism, and myokines (myostatin, irisin, and IL6). To explore muscle function, we used dynamometer-measured handgrip strength, the Timed Up and Go (TUG) test, and the Berg Balance Scale (BBS). To study brain activation, we acquired functional magnetic resonance images during three motor tasks of varying complexity. After one year of treatment, we observed an increase in lean mass and its surrogates, a decrease in fat mass, improvements in TUG test and BBS scores, and increased neural activation in certain cerebellar areas. The treatment did not significantly worsen glucose metabolism, and no side-effects were reported. Our findings support the benefits of rhGH treatment in adults with Prader-Willi syndrome and growth-hormone deficiency on body composition and suggest that it may also improve balance and brain neural activation.

Cognitive and Adaptive Effects of Early Growth Hormone Treatment in Prader-Willi Syndrome Patients: A Cohort Study

Background: Prader–Willi Syndrome (PWS) is a genetically based neurodevelopmental disease characterized by obesity, hyperphagia, and mild to moderate intellectual disability. Treatment with growth hormone (GH) could provide cognitive benefits. The objective of the present study was to compare the cognitive and adaptive performance of 31 patients with genetically confirmed PWS grouped in two cohorts, one treated with GH before 2 years old (Group 1) and the other receiving the treatment later (Group 2). Method: We compared two variables necessary to diagnose intellectual disability: intellectual performance, using the Weschler scales, and adaptive behavior, using the DABS scale. The scores were analyzed by means of non-parametric statistical tests. Results: Group 1 (n = 10) obtained higher and statistically significant scores in Total Intelligence Quotient (TIQ), General Ability Index (GAI), and General Adaptive Behavior (GAB), implying better cognitive and adaptive performance compared to Group 2. Conclusions: Treatment with GH should be administered in the early stage of development (before 2 years old) to obtain greater benefits at the cognitive and adaptive levels.

Hypogonadism in Women with Prader-Willi Syndrome-Clinical Recommendations Based on a Dutch Cohort Study, Review of the Literature and an International Expert Panel Discussion

Prader-Willi syndrome (PWS) is a rare neuroendocrine genetic syndrome. Characteristics of PWS include hyperphagia, hypotonia, and intellectual disability. Pituitary hormone deficiencies, caused by hypothalamic dysfunction, are common and hypogonadism is the most prevalent. Untreated hypogonadism can cause osteoporosis, which is already an important issue in PWS. Therefore, timely detection and treatment of hypogonadism is crucial. To increase understanding and prevent undertreatment, we (1) performed a cohort study in the Dutch PWS population, (2) thoroughly reviewed the literature on female hypogonadism in PWS and (3) provide clinical recommendations on behalf of an international expert panel. For the cohort study, we retrospectively collected results of a systematic health screening in 64 female adults with PWS, which included a medical questionnaire, medical file search, medical interview, physical examination and biochemical measurements. Our data show that hypogonadism is frequent in females with PWS (94%), but is often undiagnosed and untreated. This could be related to unfamiliarity with the syndrome, fear of behavioral changes, hygienic concerns, or drug interactions. To prevent underdiagnosis and undertreatment, we provide practical recommendations for the screening and treatment of hypogonadism in females with PWS.

Prader-Willi syndrome: an update on obesity and endocrine problems

Prader-Willi syndrome (PWS) is a rare complex genetic disorder that results from a lack of expression of the paternally inherited chromosome 15q11-q13. PWS is characterized by hypotonia and feeding difficulty in early infancy and development of morbid obesity aggravated by uncontrolled hyperphagia after childhood and adolescent. Dysmorphic facial features, delayed motor and language development, various degrees of cognitive impairment, and behavioral problems are common in PWS. Without early, intensive nutritional therapy along with behavioral modification, PWS patients develop severe obesity associated with type 2 diabetes, obstructive sleep apnea, right-side heart failure, and other obesity-related metabolic complications. Hypothalamic dysfunction in PWS can lead to several endocrine disorders, including short stature with growth hormone deficiency, hypothyroidism, central adrenal insufficiency, and hypogonadism. In this review, we discuss the natural history of PWS and the mechanisms of hyperphagia and obesity. We also provide an update on obesity treatments and recommendations for screening and monitoring of various endocrine problems that can occur in PWS.

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.

Hypogonadism in Adult Males with Prader-Willi Syndrome-Clinical Recommendations Based on a Dutch Cohort Study, Review of the Literature and an International Expert Panel Discussion

Prader-Willi syndrome (PWS) is a complex genetic syndrome characterized by hyperphagia, intellectual disability, hypotonia and hypothalamic dysfunction. Adults with PWS often have hormone deficiencies, hypogonadism being the most common. Untreated male hypogonadism can aggravate PWS-related health issues including muscle weakness, obesity, osteoporosis, and fatigue. Therefore, timely diagnosis and treatment of male hypogonadism is important. In this article, we share our experience with hypogonadism and its treatment in adult males with PWS and present a review of the literature. In order to report the prevalence and type of hypogonadism, treatment regimen and behavioral issues, we retrospectively collected data on medical interviews, physical examinations, biochemical measurements and testosterone replacement therapy (TRT) in 57 Dutch men with PWS. Fifty-six (98%) of the patients had either primary, central or combined hypogonadism. Untreated hypogonadism was associated with higher body mass index and lower hemoglobin concentrations. TRT was complicated by behavioral challenges in one third of the patients. Undertreatment was common and normal serum testosterone levels were achieved in only 30% of the patients. Based on the Dutch cohort data, review of the literature and an international expert panel discussion, we provide a practical algorithm for TRT in adult males with PWS in order to prevent undertreatment and related adverse health outcomes.

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.

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.

The use of growth hormone therapy in adults with Prader-Willi syndrome: A systematic review

OBJECTIVE

Despite clear benefits in the management of children with Prader-Willi syndrome (PWS), the role of growth hormone (GH) in adults is unclear. The aim of this study was to conduct a systematic review to evaluate the effects of GH on body composition, bone health and cardiovascular health in adults with PWS.

DESIGN

A systematic computerized literature search of the PubMed database was conducted by two independent reviewers. Inclusion criteria were individuals over the age of 16 years with a genetic diagnosis of PWS who had received GH therapy, together with assessment of body composition, bone health or cardiovascular health.

RESULTS

Twenty full-text papers met the inclusion criteria, encompassing 364 unique patients. No differences in body mass index (BMI) were noted, although 2 studies reported increased BMI after GH cessation. Data demonstrated statistically significant increases in lean body mass and reductions in percentage fat mass. Studies reported inconsistent effects of GH on cholesterol and echocardiography parameters. No studies reported differences in bone mineral density, although one reported improved bone geometry. Minor adverse events including pretibial oedema, headache and transient impaired glucose tolerance were reported in 7 studies.

CONCLUSIONS

These data suggest that GH is safe and well tolerated in adults with PWS, with evidence of improvement in body composition. Further longitudinal studies are still required to investigate the effects of GH on bone and cardiovascular health. Where GH is used in adults with PWS, this should be managed by a specialist multidisciplinary team with regular monitoring initiated.

Time for a general approval of growth hormone treatment in adults with Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a complex, multi-system, neurodevelopmental disorder characterised by neonatal muscular hypotonia, short stature, high risk of obesity, hypogonadism, intellectual disabilities, distinct behavioural/psychiatric problems and abnormal body composition with increased body fat and a deficit of lean body mass. Growth hormone (GH) deficiency and other hormone deficiencies are common due to hypothalamic dysfunction. In children with PWS GH treatment has been widely demonstrated to improve body composition, normalise height and improve psychomotor development. In adults with PWS, GH's main effects are to maintain normal body structure and metabolism. The positive effects of GH treatment on body composition, physical fitness and beneficial effects on cardiovascular risk markers, behaviour and quality of life in adults with PWS are also well established from several studies. GH treatment is approved for treatment of children with PWS in many countries, but until recently not as a treatment in young adults in the transition period or for adults in general. In this commentary we want to draw attention to the uneven global use of GH treatment, specifically in adults with PWS, and advocate for GH treatment to be approved internationally, not just for children, but also for adults with PWS and based only on the diagnosis of genetically confirmed PWS.

Disorders of hypothalamic function: Insights from Prader-Willi syndrome and the effects of craniopharyngioma

Either physical damage or being born with a specific genetic abnormality can impact on the functioning of the hypothalamus, resulting in diverse physical manifestations and/or specific behavior disorders. The impact of physical damage due to craniopharyngioma (CP) and/or surgery to remove a craniopharyngioma is compared and contrasted with the impact resulting from the genetic abnormalities associated with Prader-Willi syndrome (PWS). Similarities between PWS and CP posttreatment include hyperphagia and weight gain, low growth hormone levels, low bone density in adults, hypogonadism, disturbed temperature regulation, disturbed sleep and daytime sleepiness, memory difficulties, and problems with behavior and with peer relationships. These disturbances are an indication of the hypothalamus's central role in homeostasis. Most of the abnormalities appear to be more severe postoperatively in people with CP. Differences include higher ghrelin levels in PWS, complete absence of pituitary hormones in many cases of CP, higher incidence of thyroid dysfunction in CP, "growth without growth hormone" in obese children with CP, different types of diabetes (diabetes insipidus in CP and diabetes mellitus in PWS), and evidence of developmental delay and low IQ in people with PWS.

Genetic Subtype-Phenotype Analysis of Growth Hormone Treatment on Psychiatric Behavior in Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a complex multisystemic condition caused by a lack of paternal expression of imprinted genes from the 15q11.2-q13 region. Limited literature exists on the association between molecular classes, growth hormone use, and the prevalence of psychiatric phenotypes in PWS. In this study, we analyzed nine psychiatric phenotypes (depressed mood, anxiety, skin picking, nail picking, compulsive counting, compulsive ordering, plays with strings, visual hallucinations, and delusions) recognized in PWS and investigated associations with growth hormone treatment (GHT), deletions (DEL) and uniparental disomy (UPD) in a cohort of 172 individuals with PWS who met the criteria for analysis. Associations were explored using Pearson chi-square tests and univariable and multivariable logistic regression analyses to control for confounding exposures. This observational study of the largest dataset of patients with PWS to date suggested the following genetic subtype and phenotype correlations in psychiatric behaviors: (1) skin picking was more frequent in those with DEL vs. UPD; (2) anxiety was more common in those with UPD vs. DEL; and (3) an increased frequency of anxiety was noted in the UPD group treated with GHT compared to the DEL group. No other significant associations were found between the genetic subtype or GHT including for depressed mood, nail picking, compulsive counting, compulsive ordering, playing with strings, and visual hallucinations. Further studies will be required before any conclusions can be reached.

Intellectual functioning in Silver-Russell syndrome: First study in adults

Silver-Russell syndrome (SRS) is a rare genetic disorder (estimated incidence 1/30,000 to 100,000 live births). So far, only a few studies have focused on the cognitive profile of individuals with SRS, and these were conducted some time ago, concentrated on pediatric cohorts, and included patients who had been diagnosed using a variety of clinical diagnostic systems. There has yet to be any research on the intellectual functioning of adults with SRS. This study sought to establish the intelligence, strengths and weaknesses within intellectual profile of adults with SRS, compared with normative data. Ten individuals with 11p15 epimutation aged 18-39 years completed the Wechsler Adult Intelligence Scale-Fourth Edition. Measures of interest included participants' intelligence (Full Scale Intelligence Quotient [FSIQ]) and four domains of cognitive functioning: verbal comprehension, perceptual reasoning, working memory and processing speed. Discrepancy scores were calculated, and descriptive statistical and linear correlations were used to investigate factors associated with IQ outcome. Clinical and medical information such as rehabilitation, and perceived difficulties in daily life were collected by interviews and questionnaires. Results showed that the mean FSIQ score was in the average range (M = 95.40, SD = 18.55) and they performed best on verbal comprehension. Frequent daily difficulties were reported by patients and/or their families: learning disabilities and low self-esteem were perceived by 60% of adults. Early intervention and multidisciplinary care from childhood to adulthood are important in SRS for care potential medical, cognitive and psychosocial problems. This is the first study to document the intellectual functioning of adults with SRS.

Impact of genetic subtypes of Prader-Willi syndrome with growth hormone therapy on intelligence and body mass index

Prader-Willi syndrome (PWS) is a genomic imprinting disorder characterized by infantile hypotonia with a poor suck and failure to thrive, hypogenitalism/hypogonadism, behavior and cognitive problems, hormone deficiencies, hyperphagia, and obesity. The Stanford Binet and Wechsler (WAIS-R; WISC-III) intelligence (IQ) tests were administered on 103 individuals with PWS from two separate cohorts [University of California, Irvine (UCI) (N = 56) and Vanderbilt University (N = 47)] and clinical information obtained including growth hormone (GH) treatment, PWS molecular classes, weight and height. Significantly higher IQ scores (p < .02) were found representing the vocabulary section of the Stanford Binet test in the growth hormone (GH) treated group when compared with non-GH treatment in the pediatric-based UCI PWS cohort with a trend for stabilization of vocabulary IQ scores with age in the GH treated maternal disomy (UPD) 15 subject group. Significant differences (p = .05) were also found in the adult-based Vanderbilt PWS cohort with 15q11-q13 deletion subjects having lower Verbal IQ scores compared with UPD 15. No difference in body mass index was identified based on the PWS molecular class or genetic subtype. Medical care and response to treatment with growth hormone may influence intelligence impacted by PWS genetic subtypes and possibly age, but more studies are needed.

Prader- Willi syndrome: An uptodate on endocrine and metabolic complications

Prader-Willi syndrome (PWS) is a genetic disorder characterized by short stature, low lean body mass, muscular hypotonia, mental retardation, behavioral abnormalities, dysmorphic features, and excessive appetite with progressive obesity. It is caused by lack of expression of genes on the paternally inherited chromosome 15q11.2-q13. This genetic disorder has an estimated prevalence that ranges between 1/10,000-1/30,000. Hypothalamic dysfunction is a common finding in PWS and it has been implicated in several manifestations of this syndrome such as hyperphagia, temperature instability, high pain threshold, sleep disordered breathing, and multiple endocrine abnormalities. These include growth hormone deficiency, central adrenal insufficiency, hypogonadism, hypothyroidism, and obesity often complicated by type 2 diabetes. The aim of this manuscript is to overview the current literature on metabolic and endocrine complications of PWS, focusing on human studies and providing insights on the physio pathological mechanisms. A careful management of metabolic and endocrine complications can contribute to improve quality of life, prevent complications, and prolong life expectancy of PW patients.

Psychopathological disorders in Prader-Willi syndrome

Prader-Willi syndrome is a genetic disorder caused by chromosomal changes in segment 15q11-q13 including cognitive, mental, and behavioral symptoms, as well as a specific physical phenotype. Both the most common psychopathological changes (intellectual disability, obsessions, impulsivity, autism spectrum disorders, self-injuries) and the main psychiatric comorbidities (affective disorders, psychosis, obsessive-compulsive disorder, autism spectrum disorder) are characterized by a great heterogeneity, which warrants the need for better identification of their frequency and clinical signs. In addition to its effects on body compositionand hypotony, growth hormone has been shown to be useful for regulating patient behavior, and psychoactive drugs are also an option. Other alternatives have shown promising results in experimental trials. Adequate understanding of the psychopathology associated to Prader-Willi syndrome would allow for improving clinical approach, symptom identification, detection of comorbidities, and administration of more effective treatments, leading to better clinical outcomes.

Impact of transitional care on endocrine and anthropometric parameters in Prader-Willi syndrome

CONTEXT

The transition of patients with Prader-Willi syndrome (PWS) to adult life for medical care is challenging because of multiple comorbidities, including hormone deficiencies, obesity and cognitive and behavioral disabilities.

OBJECTIVE

To assess endocrine management, and metabolic and anthropometric parameters of PWS adults who received (n = 31) or not (n = 64) transitional care, defined as specialized pediatric care followed by a structured care pathway to a multidisciplinary adult team.

PATIENTS AND STUDY DESIGN

Hormonal and metabolic parameters were retrospectively recorded in 95 adults with PWS (mean ± s.d. age 24.7 ± 8.2 years, BMI: 39.8 ± 12.1 kg/m²) referred to our Reference Center and compared according to transition.

RESULTS

Among the entire cohort, 35.8% received growth hormone (GH) during childhood and 16.8% had a GH stimulation test after completion of growth. In adulthood, 14.7% were treated with GH, 56.8% received sex-hormone therapy, whereas 91.1% were hypogonadic and 37.9% had undergone valid screening of the corticotropic axis. The main reason for suboptimal endocrine management was marked behavioral disorders. Patients receiving transitional care were more likely to have had a GH stimulation test and hormonal substitutions in childhood. They also had a lower BMI, percentage of fat mass, improved metabolic parameters and fewer antidepressant treatments. Transitional care remained significantly associated with these parameters in multivariate analysis when adjusted on GH treatment.

CONCLUSION

A coordinated care pathway with specialized pediatric care and transition to a multidisciplinary adult team accustomed to managing complex disability including psychiatric troubles are associated with a better health status in adults with PWS.

Treatment with growth hormone in the prader-willi syndrome

INTRODUCTION

The Prader-Willi syndrome (PWS) is a rare genetic disorder caused by absence of expression of the paternal alleles in región 15q11.2-q13. Obesity and hormonal deficiencies, especially of growth hormone (GH), are the most important signs from the therapeutic viewpoint. Recombinant GH (rGH) is effective in children and represents the mainstay in treatment; by contrast, little evidence in available in adult patients.

OBJECTIVE

To review the reported evidence on the beneficial and adverse effects of treatment with rGH in children and adults.

DESIGN

A review was made of 62 original articles published between 2000 and 2017 using the PubMed database.

RESULTS

In pediatric and adult PWS, rGH improves body morphology and composition, physical performance, cognition, psychomotor development, respiratory function, and quality of life with few adverse effects.

CONCLUSIONS

Treatment with rGH is effective and safe and improves quality of life in both children and adults with PWS.

A systematic review of the methodological and practical challenges of undertaking randomised-controlled trials with cognitive disability populations

Approximately 10% of the world's population have a cognitive disability. Cognitive disabilities can have a profound impact on a person's social, cognitive or mental functioning, requiring high levels of costly health and social support. Therefore, it is imperative that interventions and services received are based upon a sound evidence-base. For many interventions for this population, this evidence-base does not yet exist and there is a need for more Randomised Controlled Trials (RCTs). The process of conducting RCTs with disabled populations is fraught with methodological challenges. We need a better understanding of these methodological barriers if the evidence-bases are to be developed. The purpose of this study was to explore the methodological and practical barriers to conducting trials with adults with cognitive disabilities. As a case example, the literature regarding RCTs for people with intellectual disabilities (ID) was used to highlight these pertinent issues. A systematic literature review was conducted of RCTs with adults with ID, published from 2000 to 2017. A total of 53 papers met the inclusion criteria and were reviewed. Some of the barriers reported were specific to the RCT methodology and others specific to people with disabilities. Notable barriers included; difficulties recruiting; obtaining consent; resistance to the use of control groups; engaging with carers, staff and stakeholders; the need to adapt interventions and resources to be disability-accessible; and staff turnover. Conducting RCTs with people with cognitive disabilities can be challenging, however with reasonable adjustments, many of these barriers can be overcome. Researchers are not maximising the sharing of their experience-base. As a result, the development of evidence-bases remains slow and the health inequities of people with disabilities will continue to grow. The importance of the MRC guidelines on process evaluations, together with implications for the dissemination of 'evidence-base' and 'experience-base' are discussed.

Certainty of genuine treatment increases drug responses among intellectually disabled patients

Objective:

To determine the placebo component of treatment responses in patients with intellectual disability (ID).

Methods:

A statistical meta-analysis comparing bias-corrected effect sizes (Hedges g) of drug responses in open-label vs placebo-controlled clinical trials was performed, as these trial types represent different certainty of receiving genuine treatment (100% vs 50%). Studies in fragile X, Down, Prader-Willi, and Williams syndrome published before June 2015 were considered.

Results:

Seventeen open-label trials (n = 261, 65% male; mean age 23.6 years; mean trial duration 38 weeks) and 22 placebo-controlled trials (n = 721, 62% male; mean age 17.1 years; mean trial duration 35 weeks) were included. The overall effect size from pre to post treatment in open-label studies was g = 0.602 (p = 0.001). The effect of trial type was statistically significant (p = 0.001), and revealed higher effect sizes in studies with 100% likelihood of getting active drug, compared to both the drug and placebo arm of placebo-controlled trials. We thus provide evidence for genuine placebo effects, not explainable by natural history or regression toward the mean, among patients with ID.

Conclusions:

Our data suggest that clinical trials in patients with severe cognitive deficits are influenced by the certainty of receiving genuine medication, and open-label design should thus not be used to evaluate the effect of pharmacologic treatments in ID, as the results will be biased by an enhanced placebo component.

Cognitive and adaptive advantages of growth hormone treatment in children with Prader-Willi syndrome

BACKGROUND

People with Prader-Willi syndrome (PWS) typically have mild to moderate intellectual deficits, compulsivity, hyperphagia, obesity, and growth hormone deficiencies. Growth hormone treatment (GHT) in PWS has well-established salutatory effects on linear growth and body composition, yet cognitive benefits of GHT, seen in other patient groups, have not been well studied in PWS.

METHODS

Study 1 included 96 children and youth with PWS aged 4-21 years who naturalistically varied in their exposures to GHT. Controlling for socioeconomic status, analyses compared cognitive and adaptive behavior test scores across age-matched treatment naïve versus growth hormone treated children. Study II assessed if age of treatment initiation or treatment duration was associated with subsequent cognition or adaptive behavior in 127, 4- to 21-year olds with PWS. Study III longitudinally examined cognitive and adaptive behavior in 168 participants who were either consistently on versus off GHT for up to 4-5 years.

RESULTS

Compared to the treatment naïve group, children receiving GHT had significantly higher Verbal and Composite IQs, and adaptive communication and daily living skills. Children who began treatment before 12 months of age had higher Nonverbal and Composite IQs than children who began treatment between 1 and 5 years of age. Longitudinally, the groups differed in their intercepts, but not slopes, with each group showing stable IQ and adaptive behavior scores over time.

CONCLUSIONS

Cognitive and adaptive advantages should be considered an ancillary benefit and additional justification for GHT in people with PWS. Future efforts need to target apparent socioeconomic inequities in accessing GHT in the PWS population.

Diagnosis and treatment of GH deficiency in Prader-Willi syndrome

Prader-Willi syndrome (PWS) results from under-expression of the paternally-derived chromosomal region 15q11-13. Growth failure is a recognized feature of PWS, and both quantitative and qualitative defects of the GH/IGF-I axis revealing GH deficiency (GHD) have been demonstrated in most children with PWS. In PWS adults, criteria for GHD are biochemically fulfilled in 8-38% of the studied cohorts. Published data support benefits of early institution of GH therapy (GHT) in PWS children, with positive effects on statural growth, body composition, metabolic homeostasis, and neurocognitive function. Like in pediatric PWS, GHT also yields beneficial effects on lean and body fat, exercise capacity, and quality of life of PWS adults. Although GHT has been generally administered safely in PWS children and adults, careful surveillance of risks is mandatory during prolonged GH replacement for all PWS individuals.

Effect of cessation of GH treatment on cognition during transition phase in Prader-Willi syndrome: results of a 2-year crossover GH trial

BACKGROUND

Patients with Prader-Willi syndrome (PWS) have a cognitive impairment. Growth hormone (GH) treatment during childhood improves cognitive functioning, while cognition deteriorates in GH-untreated children with PWS. Cessation of GH treatment at attainment of adult height (AH) might deteriorate their GH-induced improved cognition, while continuation might benefit them. We, therefore, investigated the effects of placebo versus GH administration on cognition in young adults with PWS who were GH-treated for many years during childhood and had attained AH.

METHOD

Two-year, randomized, double-blind, placebo-controlled cross-over study in 25 young adults with PWS. Cross-over intervention with placebo and GH (0.67 mg/m2/day), both during 1 year.

RESULTS

Total (TIQ), verbal (VIQ) and performance IQ (PIQ) did not deteriorate during 1 year of placebo, compared to GH treatment (p > 0.322). Young adults with a lower TIQ had significantly more loss of TIQ points during placebo versus GH, in particular VIQ decreased more in those with a lower VIQ. The effect of placebo versus GH on TIQ, VIQ and PIQ was not different for gender or genotype.

CONCLUSIONS

Compared to GH treatment, 1 year of placebo did not deteriorate cognitive functioning of GH-treated young adults with PWS who have attained AH. However, patients with a lower cognitive functioning had more loss in IQ points during placebo versus GH treatment. The reassuring finding that 1 year of placebo does not deteriorate cognitive functioning does, however, not exclude a gradual deterioration of cognitive functioning on the long term.

TRIAL REGISTRATION

ISRCTN24648386 , NTR1038 , Dutch Trial Register, www.trialregister.nl . Registered 16 August 2007.

Epigenetic alterations induced by environmental stress associated with metabolic and neurodevelopmental disorders

Epigenetics is a gene regulation mechanism that does not depend on genomic DNA sequences but depends on chemical modification of genomic DNA and histone proteins around which DNA is wrapped. The failure of epigenetic mechanisms is known to cause various congenital disorders. It is also known that the failures of epigenetic mechanisms causes various acquired disorders since epigenetic modifications of the genome (i.e., "epigenome") are more vulnerable to environmental stress, such as malnutrition, environmental chemicals, and mental stress, than the "genome," especially during the early period of life. However, the epigenome has a reversible property since it is based on removable residues on genomic DNA. Thus, environmentally induced epigenomic alterations can be potentially restored. In fact, some medicines, especially for psychiatric diseases, are known to restore an altered epigenome, resulting in the correction of gene expression. Several lines of evidence suggest that environmentally induced epigenomic alterations are not erased completely during gametogenesis, but are transmitted to subsequent generations with disease phenotypes. In accordance with these understandings, I would like to propose the development of epigenomic-based preemptive medicine that consists of the early detection of the developmental origins of diseases using epigenomic signatures and the early intervention that take advantages of the use of epigenomic reversibility.

Growth hormone therapy for Prader-willi syndrome: challenges and solutions

Prader-Willi syndrome (PWS) is characterized by a dysregulation of growth hormone (GH)/insulin-like growth factor I axis, as the consequence of a complex hypothalamic involvement. PWS' clinical picture seems to resemble the classic non-PWS GH deficiency (GHD), including short stature, excessive body fat, decreased muscle mass, and impaired quality of life. GH therapy is able to ameliorate the phenotypic appearance of the syndrome, as well as to improve body composition, physical strength, and cognitive level. In this regard, however, some pathophysiologic and clinical questions still remain, representing a challenge to give the most appropriate care to PWS patients. Data about the prevalence of GHD in PWS children are not unequivocal, ranging from 40% to 100%. In this context, to establish whether the presence (or not) of GHD may have a different effect on clinical course during GH therapy may be helpful. In addition, the comparison of GH effects in PWS children diagnosed as small for gestational age with those obtained in subjects born appropriate for gestational age is of potential interest for future trials. Emerging information seems to demonstrate the maintenance of beneficial effects of GH therapy in PWS subjects after adolescent years. Thus, GH retesting after achievement of final height should be taken into consideration for all PWS patients. However, it is noteworthy that GH administration exerts positive effects both in PWS adults with and without GHD. Another critical issue is to clarify whether the genotype-phenotype correlations may be relevant to specific outcome measures related to GH therapy. Moreover, progress of our understanding of the role of GH replacement and concomitant therapies on bone characteristics of PWS is required. Finally, a long-term surveillance of benefits and risks of GH therapy is strongly recommended for PWS population, since most of the current studies are uncontrolled and of short duration.

Single Gene and Syndromic Causes of Obesity: Illustrative Examples

Obesity is a significant health problem in westernized societies, particularly in the United States where it has reached epidemic proportions in both adults and children. The prevalence of childhood obesity has doubled in the past 30 years. The causation is complex with multiple sources, including an obesity promoting environment with plentiful highly dense food sources and overall decreased physical activity noted for much of the general population, but genetic factors clearly play a role. Advances in genetic technology using candidate gene approaches, genome-wide association studies, structural and expression microarrays, and next generation sequencing have led to the discovery of hundreds of genes recognized as contributing to obesity. Polygenic and monogenic causes of obesity are now recognized including dozens of examples of syndromic obesity with Prader-Willi syndrome, as a classical example and recognized as the most common known cause of life-threatening obesity. Genetic factors playing a role in the causation of obesity will be discussed along with the growing evidence of single genes and the continuum between monogenic and polygenic obesity. The clinical and genetic aspects of four classical but rare obesity-related syndromes (ie, Prader-Willi, Alström, fragile X, and Albright hereditary osteodystrophy) will be described and illustrated in this review of single gene and syndromic causes of obesity.

Prader-Willi Syndrome: The Disease that Opened up Epigenomic-Based Preemptive Medicine

Prader-Willi syndrome (PWS) is a congenital neurodevelopmental disorder caused by loss of function of paternally expressed genes on chromosome 15 due to paternal deletion of 15q11–q13, maternal uniparental disomy for chromosome 15, or an imprinting mutation. We previously developed a DNA methylation-based PCR assay to identify each of these three genetic causes of PWS. The assay enables straightforward and rapid diagnosis during infancy and therefore allows early intervention such as nutritional management, physical therapy, or growth hormone treatment to prevent PWS patients from complications such as obesity and type 2 diabetes. It is known that various environmental factors induce epigenomic changes during the perinatal period, which increase the risk of adult diseases such as type 2 diabetes and intellectual disabilities. Therefore, a similar preemptive approach as used in PWS would also be applicable to acquired disorders and would make use of environmentally-introduced “epigenomic signatures” to aid development of early intervention strategies that take advantage of “epigenomic reversibility”.

Pharmacotherapy for mental health problems in people with intellectual disability

PURPOSE OF REVIEW

Psychotropic medications are commonly prescribed to people with intellectual disability. We reviewed current evidence-based pharmacotherapy options and recent updates to guide clinicians in their medication management plans.

RECENT FINDINGS

Antipsychotics, particularly risperidone, appear to be effective in reducing problem behaviors in children with intellectual disability. Evidence in adults is inconclusive. Methylphenidate appears to be effective, and α-agonists appear promising in reducing attention-deficit hyperactivity disorder symptoms. Lithium might be effective in reducing aggression. Evidence is limited to support the use of antiepileptic drugs, anxiolytics, and naltrexone for management of problem behaviors. Antidepressants may be poorly tolerated and might not be effective in reducing repetitive/stereotypic behaviors.In recent trials, glutamatergic and GABAergic agents for fragile X syndrome, and acetylcholinesterase inhibitors for Down's syndrome, failed to show efficacy. Growth hormone treatment might improve cognition and behavior in Prader-Willi syndrome population. Results from oxytocin trials on social behaviors are inconclusive albeit promising. Melatonin appears to improve sleep. Most trials of dietary supplements did not show benefits.

SUMMARY

Evidence-based pharmacotherapy options in people with intellectual disability are limited, and many agents can cause substantial adverse events. For this reason, clinicians should consider pharmacotherapy as only a part of comprehensive treatment, and regularly assess drug effects, adverse events, and the feasibility of decreasing dose or withdrawing medications.

Prader-Willi syndrome: a review of clinical, genetic, and endocrine findings

INTRODUCTION

Prader-Willi syndrome (PWS) is a multisystemic complex genetic disorder caused by lack of expression of genes on the paternally inherited chromosome 15q11.2-q13 region. There are three main genetic subtypes in PWS: paternal 15q11-q13 deletion (65-75 % of cases), maternal uniparental disomy 15 (20-30 % of cases), and imprinting defect (1-3 %). DNA methylation analysis is the only technique that will diagnose PWS in all three molecular genetic classes and differentiate PWS from Angelman syndrome. Clinical manifestations change with age with hypotonia and a poor suck resulting in failure to thrive during infancy. As the individual ages, other features such as short stature, food seeking with excessive weight gain, developmental delay, cognitive disability and behavioral problems become evident. The phenotype is likely due to hypothalamic dysfunction, which is responsible for hyperphagia, temperature instability, high pain threshold, hypersomnia and multiple endocrine abnormalities including growth hormone and thyroid-stimulating hormone deficiencies, hypogonadism and central adrenal insufficiency. Obesity and its complications are the major causes of morbidity and mortality in PWS.

METHODS

An extensive review of the literature was performed and interpreted within the context of clinical practice and frequently asked questions from referring physicians and families to include the current status of the cause and diagnosis of the clinical, genetics and endocrine findings in PWS.

CONCLUSIONS

Updated information regarding the early diagnosis and management of individuals with Prader-Willi syndrome is important for all physicians and will be helpful in anticipating and managing or modifying complications associated with this rare obesity-related disorder.

Growth Hormone Therapy in Adults with Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is characterized by hyperphagia, obesity if food intake is not strictly controlled, abnormal body composition with decreased lean body mass and increased fat mass, decreased basal metabolic rate, short stature, low muscle tone, cognitive disability, and hypogonadism. In addition to improvements in linear growth, the benefits of growth hormone therapy on body composition and motor function in children with PWS are well established. Evidence is now emerging on the benefits of growth hormone therapy in adults with PWS. This review summarizes the current literature on growth hormone status and the use of growth hormone therapy in adults with PWS. The benefits of growth hormone therapy on body composition, muscle strength, exercise capacity, certain measures of sleep-disordered breathing, metabolic parameters, quality of life, and cognition are covered in detail along with potential adverse effects and guidelines for initiating and monitoring therapy.

Growth hormone treatment improves vitality and behavioural issues in children with Prader-Willi syndrome

AIM

Prader-Willi syndrome is a neurogenetic disorder, with characteristics such as obesity, short stature, muscular weakness, intellectual deficiencies and deviant social behaviour. This study evaluated whether growth hormone treatment of children with Prader-Willi syndrome resulted in possible and lasting effects on their cognition and behaviour.

METHODS

We randomised six girls and 13 boys to either a treatment group or a control group. The treatment group received growth hormone (Genotropin(®) 0.033 mg/kg/day) for 2 years, while the control group did not receive treatment in the first year and then received a double dose in the second year. Treatment was then stopped in both groups for 6 months.

RESULTS

Both groups showed the same intellectual disabilities at the start of the study, and no difference was found after the first and second years. The parents reported that the children showed increased vitality during treatment. When treatment was stopped, the children showed a marked exacerbation of behavioural problems, a significant increase in body fat and a decrease in insulin-like growth factor 1 levels.

CONCLUSION

We believe this is the first study to show that abrupt-ceasing growth hormone treatment led to a successive deterioration in behavioural problems in children with Prader-Willi syndrome.

Prader-Willi syndrome and growth hormone deficiency

Prader-Willi syndrome (PWS) is a rare multisystem genetic disorder demonstrating great variability with changing clinical features during patient's life. It is characterized by severe hypotonia with poor sucking and feeding difficulties in early infancy, followed by excessive eating and gradual development of morbid obesity in later infancy or early childhood. The phenotype is most probably due to hypothalamic dysfunction which is also responsible for growth hormone (GH) and thyroid-stimulating hormone (TSH) deficiencies, central adrenal insufficiency and hypogonadism. The multidimensional problems of patients with PWS can be managed with multidisciplinary approach. Reduced GH secretion, low peak GH response to stimulation, decreased spontaneous GH secretion and low serum IGF-1 levels in PWS patients have been documented in many studies. GH therapy has multiple beneficial effects on growth and body composition, motor and mental development in PWS patients. The recommended dosage for GH is 0.5-1 mg/m2/day. GH therapy should not be started in the presence of obstructive sleep apnea syndrome, adenotonsillar hypertrophy, severe obesity and diabetes mellitus. GH treatment should be considered for patients with genetically confirmed PWS in conjunction with dietary, environmental and life-style measures.

Glucose homeostasis in adults with Prader-Willi syndrome during treatment with growth hormone: results from a 12-month prospective study

OBJECTIVES

To investigate glucose homeostasis in relation to body mass index (BMI) in adults with PWS before and after GH therapy.

DESIGN

We prospectively investigated the effects of a 12-month GH treatment on body composition and glucose homeostasis in relation to BMI in 39 adults, mean (±SD) age=28.6 (6.5) years with genetically verified PWS. We compared the results for different BMI categories (<25 kg/m²; 25-30 kg/m²; >30 kg/m²) and performed a regression analysis to detect predictors for homeostasis model of assessment-insulin resistance (HOMA-IR).

RESULTS

The baseline HOMA-IR was higher, with BMI of >30 kg/m². Our main findings were as follows: i) GH treatment (mean final dose, 0.6 (0.25) mg) was associated with small increases in fasting p-glucose, 2-h p-glucose by oral glucose load tolerance test, HOMA-IR and lean mass, and a reduction in fat mass. ii) Whereas the baseline HOMA-IR was associated with increased BMI (>30 kg/m²), we found no differences in HOMA-IR among the BMI categories after 12 months of GH. iii) Stepwise linear regression identified the triglyceride level as the strongest predictor of HOMA-IR at baseline, whereas an increase in VAT was the strongest predictor of the increase in HOMA-IR after therapy.

CONCLUSIONS

GH treatment for 12 months in adults with PWS resulted in an increase in HOMA-IR, irrespective of BMI, confirming that control of HbA1c is essential during GH treatment in PWS.

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.

GrowthHormone Research Society workshop summary: consensus guidelines for recombinant human growth hormone therapy in Prader-Willi syndrome

CONTEXT

Recombinant human GH (rhGH) therapy in Prader-Willi syndrome (PWS) has been used by the medical community and advocated by parental support groups since its approval in the United States in 2000 and in Europe in 2001. Its use in PWS represents a unique therapeutic challenge that includes treating individuals with cognitive disability, varied therapeutic goals that are not focused exclusively on increased height, and concerns about potential life-threatening adverse events.

OBJECTIVE

The aim of the study was to formulate recommendations for the use of rhGH in children and adult patients with PWS.

EVIDENCE

We performed a systematic review of the clinical evidence in the pediatric population, including randomized controlled trials, comparative observational studies, and long-term studies (>3.5 y). Adult studies included randomized controlled trials of rhGH treatment for ≥ 6 months and uncontrolled trials. Safety data were obtained from case reports, clinical trials, and pharmaceutical registries.

METHODOLOGY

Forty-three international experts and stakeholders followed clinical practice guideline development recommendations outlined by the AGREE Collaboration (www.agreetrust.org). Evidence was synthesized and graded using a comprehensive multicriteria methodology (EVIDEM) (http://bit.ly.PWGHIN).

CONCLUSIONS

Following a multidisciplinary evaluation, preferably by experts, rhGH treatment should be considered for patients with genetically confirmed PWS in conjunction with dietary, environmental, and lifestyle interventions. Cognitive impairment should not be a barrier to treatment, and informed consent/assent should include benefit/risk information. Exclusion criteria should include severe obesity, uncontrolled diabetes mellitus, untreated severe obstructive sleep apnea, active cancer, or psychosis. Clinical outcome priorities should vary depending upon age and the presence of physical, mental, and social disability, and treatment should be continued for as long as demonstrated benefits outweigh the risks.

Application of in vitro [³⁵S]GTPγ-S autoradiography in studies of growth hormone effects on opioid receptors in the male rat brain

Chronic treatment with opiates may inhibit cell growth and trigger apoptosis. On the contrary, growth hormone (GH) has been demonstrated to stimulate neurogenesis and counteract apoptosis. We recently demonstrated that recombinant human GH (rhGH) may reverse opiate-induced apoptosis in cells derived from prenatal mouse hippocampus. Thus, GH might be able to prevent the impaired cognitive capabilities that may occur in both humans and other mammals in connection to chronic opiate treatment. In order to explore the mechanism by which GH exerts its beneficial effects we here examined the impact of GH treatment on the levels of delta and mu opioid peptide (DOP and MOP, respectively) receptors in the male rat brain. The rats were treated with rhGH (Genotropin®) at two different doses (0.07 and 0.7 IU/kg), twice daily, during 7 days. Following decapitation, the levels of DOP and MOP receptor functionality were determined using [³⁵S]GTPγS autoradiography. The results demonstrate that rhGH affects the levels of the MOP receptor functionality in certain areas of the brain. These alterations were seen in e.g. amygdala and thalamus, i.e. regions that recently have been implicated in learning and memory. The activity level of DOP receptors was not affected. Thus, the data support that the beneficial effect of GH on counteracting apoptosis might involve a direct or indirect effect on the MOP but not the DOP receptor.

Effects of recombinant human growth hormone therapy in adults with Prader-Willi syndrome: a meta-analysis

OBJECTIVE

Prader-Willi syndrome (PWS) is associated with GH deficiency, deleterious changes in body composition and function. As the effects of recombinant human GH (rhGH) in PWS adults have not been well established, we sought to conduct a meta-analysis of pertinent studies.

DESIGN

Meta-analysis of studies examining the effects of rhGH therapy in PWS adults.

PATIENTS

One hundred and thirty four PWS adults (75 men, 59 women).

MEASUREMENTS

Literature searches, including publications (PubMed, EMBASE and the Cochrane Register), and abstracts presented at meetings through July 2011 describing studies of rhGH therapy in PWS adults; 8/1194 articles, describing unique cohorts, were included. Two authors independently extracted data and examined study quality.

RESULTS

rhGH therapy for 12 months led to [weighted mean difference (95% CI)] decreased body fat [-2·91% (-3·90, -1·91)], visceral [-32·97 cm(2) (-55·67, -10·26)] and subcutaneous adiposity [-55·24 cm(2) (-89·05, -21·44)], and increased lean body mass (LBM) [2·41 Kg (1·32, 3·49)]. Similar changes in body fat [-2·89% (-4·69, -1·07)] and LBM [2·82 Kg (1·31, 4·33)] were found in longer studies. There were no changes in body mass index (BMI) or lipids. There was a small increase in fasting glucose [0·27 mmol/l (0·05, 0·49)] and trends towards higher fasting insulin [20·24 pmol/l (-0·55, 41·02)] and insulin resistance [HOMA: 0·60 (-0·04, 1·24)] after rhGH therapy for 12 months.

CONCLUSIONS

In PWS adults, rhGH therapy led to decreased body adiposity and increased LBM without changes in BMI or lipids. There was a small increase in fasting glucose and trends towards higher insulin and insulin resistance.