Anti-Obesity Medication Use in Children and Adolescents with Prader-Willi Syndrome: Case Review and Literature Search

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.

Effect of semaglutide on weight loss and glycaemic control in patients with Prader-Willi Syndrome and type 2 diabetes

Prader-Willi Syndrome (PWS) is the most common genetic cause of obesity, occurring in approximately 1 in 15,000 newborns. It results from the lack of expression of genes on the paternal allele of the chromosomal region 15q-11q13 (65-75% due to type 1 or type 2 deletion). Individuals with PWS experience associated symptoms such as hypotonia, hyperphagia, and early-onset obesity (before 5 years of age). Around 20% of adults with PWS also develop type 2 diabetes. Previous studies have shown the beneficial effects of GLP1-RA medications, such as exenatide and liraglutide, in treating type 2 diabetes in PWS. However, there is limited information available on the use of semaglutide in PWS. This study aimed to evaluate the effects of semaglutide on weight loss and glycaemic control in four patients with PWS and type 2 diabetes associated with obesity. The patients were started on weekly subcutaneous progressive doses of semaglutide.

A Personalized Approach to Determining the Caloric Needs of Children with Prader-Willi Syndrome Treated with Growth Hormone

Prader-Willi Syndrome (PWS) is the most frequent cause of genetic obesity. Early reports indicate that children with PWS require 20-40% fewer calories than healthy children to maintain adequate growth. Growth hormone treatment for children with PWS, approved in 2000, affects the body composition and probably affects energy requirements. This retrospective cross-sectional study analyzed the caloric intake in children with PWS aged from 6 months to 12 years old who underwent growth hormone treatment, comparing the patients' caloric intake calculated from parent-recorded dietary intake versus the recommended caloric intake for healthy children, taking into account the age, sex, height, weight, and physical activity. We analyzed the data from 25 patients (13 (52%) boys; mean age, 6.72 ± 2.81 y; median age at starting growth hormone treatment, 1.4 y (IQR: 0.78-2.29); 17 (68%) normal weight and 8 (32%) overweight or obese). The mean daily energy intake was 1208 ± 186 kcal/d, representing 96.83% ± 18.66 of the recommended caloric intake for healthy children. The caloric intake in children with PWS treated with growth hormone was very similar to that recommended for healthy children; thus, we should rethink the dietary recommendations for these children.

Pharmacological Support for the Treatment of Obesity-Present and Future

Obesity is a growing civilization problem, associated with a number of negative health consequences affecting almost all tissues and organs. Currently, obesity treatment includes lifestyle modifications (including diet and exercise), pharmacologic therapies, and in some clinical situations, bariatric surgery. These treatments seem to be the most effective method supporting the treatment of obesity. However, they are many limitations to the options, both for the practitioners and patients. Often the comorbidities, cost, age of the patient, and even geographic locations may influence the choices. The pharmacotherapy of obesity is a fast-growing market. Currently, we have at our disposal drugs with various mechanisms of action (directly reducing the absorption of calories-orlistat, acting centrally-bupropion with naltrexone, phentermine with topiramate, or multidirectional-liraglutide, dulaglutide, semaglutide). The drugs whose weight-reducing effect is used in the course of the pharmacotherapy of other diseases (e.g., glucose-sodium cotransporter inhibitors, exenatide) are also worth mentioning. The obesity pharmacotherapy is focusing on novel therapeutic agents with improved safety and efficacy profiles. These trends also include an assessment of the usefulness of the weight-reducing properties of the drugs previously used for other diseases. The presented paper is an overview of the studies related to both drugs currently used in the pharmacotherapy of obesity and those undergoing clinical trials, taking into account the individual approach to the patient.

The efficacy of intranasal oxytocin in patients with Prader-Willi syndrome: A systematic review and meta-analysis

BACKGROUND AND AIMS

Prader-Willi Syndrome (PWS) is a rare genetic disease. Oxytocin is a neuropeptide hormone that impacts fear, and social recognition. Intranasal administration of oxytocin can be utilized to treat PWS patients. The results of published trials assessing the effects of intranasal oxytocin in PWS are variable. The current systematic review aims to investigate the efficacy of oxytocin in Prader-Willi patients.

METHODS

We conducted a systematic literature search on Pubmed, Web of Science, and Scopus from inception to March 2022 for relevant interventional randomized controlled trials (RCTs) reporting the effect of oxytocin in patients with Prader-Willi syndrome. We assessed the quality of included trials using the Cochrane tool risk of bias 1. We performed the meta-analysis with Revman software version 5.4. In addition, we visualized our results using forest plots. We assessed the heterogeneity by using the Chi-square test.

RESULTS

Relevant to hyperphagia, the data extracted in three studies comprising 92 patients did not show positive outcomes of oxytocin compared to placebo (MD = 0.18; 95% CI: -0.44, 0.80; P = 0.56). Three studies that included 94 patients revealed no significant effects regarding weight between oxytocin and placebo (MD = 0.30; 95% CI: -0.22, 0.83; P = 0.25). The Aberrant Behaviour Checklist found that group-administered oxytocin improved behaviour compared to their counterpart who received a placebo.

CONCLUSION

Oxytocin didn't have significant effects on hyperphagia or weight. To establish the impact of oxytocin in Prader-Willi patients, additional prospective, large-sample randomized controlled trials (RCTs) are needed to avoid controversy.

Topiramate for Weight Management in Children with Severe Obesity

Background: Topiramate has been shown to result in significant weight loss compared to placebo in adults with obesity. However, there are no consensus guidelines on the acceptability, safety, and efficacy of topiramate for weight loss in children. We present a literature review and case series on topiramate use in young children with severe obesity. Methods: We performed a PubMed search from January 2000 to February 2022 utilizing keywords, "topiramate" and "obesity" and "children" and "adolescent." For our case series, children were identified through retrospective chart review from a multidisciplinary weight management program. Eligibility criteria: age ≤12 years, class II or III obesity, completed 16 weeks of topiramate therapy as adjunct to lifestyle modifications. Semistructured interviews were conducted with one parent to review side effects. Results: Literature search yielded nine articles. All studies reported trends toward BMI reduction and weight loss with topiramate monotherapy. Five children met case series eligibility (mean age 10 years 3 months ±1.5 years, 60% female). After 16 weeks of topiramate, all children had a decrease in BMI as a percentage of the 95th percentile (mean -12% [-5% to -18%]). Parents reported improvement in impulsive eating and decreased desire to overeat compared to baseline. Four out of five reported no side effects, one reported drowsiness which resolved by dosing at nighttime. Conclusions: Results suggest that topiramate is well tolerated and may be utilized for weight management in younger children. A randomized controlled trial investigating the impact of topiramate for weight management in this age group is warranted.

Prader–Willi Syndrome: Possibilities of Weight Gain Prevention and Treatment

Prader–Willi syndrome (PWS) is a complex genetic disorder which involves the endocrine and neurologic systems, metabolism, and behavior. The aim of this paper is to summarize current knowledge on dietary management and treatment of PWS and, in particular, to prevent excessive weight gain. Growth hormone (GH) therapy is the recommended standard treatment for PWS children, because it improves body composition (by changing the proportion of body fat and lean body mass specifically by increasing muscle mass and energy expenditure), linear growth, and in infants, it promotes psychomotor and IQ development. In early childhood, the predominant symptom is hyperphagia which can lead to early onset, severe obesity with different obesity-related comorbidities. There are several studies on anti-obesity medications (metformin, topiramate, liraglutide, setmelanotide). However, these are still limited, and no widely accepted consensus guideline exists concerning these drugs in children with PWS. Until there is a specific treatment for hyperphagia and weight gain, weight must be controlled with the help of diet and exercise. Below the age of one year, children with PWS have no desire to eat and will often fail to thrive, despite adequate calories. After the age of two years, weight begins to increase without a change in calorie intake. Appetite increases later, gradually, and becomes insatiable. Managing the progression of different nutritional phases (0–4) is really important and can delay the early onset of severe obesity. Multidisciplinary approaches are crucial in the diagnosis and lifelong follow-up, which will determine the quality of life of these patients.