Urs Eiholzer

Background: Adolescent obesity remains a challenge with limited treatment options. GLP-1 receptor agonists such as liraglutide (Saxenda^®) have shown efficacy in trials, but real-world data in youth are scarce. Methods: This retrospective longitudinal, non-interventional study analyzed 22 adolescents treated with liraglutide in a Swiss pediatric endocrinology center. All received non-structured nutritional/lifestyle counseling with three-monthly follow-up. BMI standard deviation scores (BMI-SDS) and adverse effects were recorded. Results: The mean age at initiation was 14.9 years (range 12.5–17.5); 15 patients had Southern European immigrant background. Mean treatment duration was 8.2 months (range 1–18). BMI-SDS decreased significantly from +2.63 (IQR +2.4/+2.8) to +2.40 (IQR +2.2/+2.6). Median intra-individual reduction was −0.20 (IQR −0.28/−0.10), p = 0.0003 with large effect size (rb = −0.77). Thirteen patients discontinued treatment, mainly due to insufficient weight loss or mild nausea. In the patients continuing therapy BMI-SDS decreased from +2.59 (IQR +2.4/+2.8) to +2.08 (IQR +1.9/+2.4). No serious adverse events occurred. Conclusions: Liraglutide showed a comparable efficacy to the pivotal clinical trial in reducing BMI-SDS in adolescents, while the side-effect profile was similarly mild and consistent with previously reported data. Discontinuation rates remained high, highlighting the need for thorough pre-treatment counseling on expected mild, transient symptoms and strategies to mitigate nausea. Future prospective studies are needed to assess long-term outcomes and identify patient characteristics associated with greater treatment success, to better individualize GLP-1–based therapy in adolescent obesity.

Background/Objectives: The 2019 Swiss growth references for height, weight, and BMI were based on a large dataset from the German-speaking part of Switzerland (Cohort 2019). The current study aimed to ensure national representativeness by proportionate amounts of additional data from the French-speaking (Suisse Romande) and Italian-speaking (Ticino) regions to validate the 2019 growth curves and to update the national growth references. It also investigated the influence of parental migration background on child growth. Methods: Anthropometric data from 43,290 children and adolescents—including 11,816 new cases—were analyzed (Cohort 2019 + 2025). Percentile curves were modeled using the Generalized Additive Models for Location, Scale, and Shape (GAMLSS) framework. Results: The extended dataset largely confirms the 2019 growth references. Variations in height percentiles were small and clinically negligible. Clinically relevant differences in BMI percentiles were observed in girls, with the most pronounced deviations—up to 0.8 kg/m²—at the 97th percentile. Analyses by parental migration background revealed relevant differences in BMI. Conclusions: The extended Swiss Growth References (Cohort 2019 + 2025) are robust and provide valid reference data for all Swiss children and adolescents, offering contemporary tools for decision-making in clinical practice. To maintain their validity over time, targeted updates are required, with special attention to demographic changes resulting from migration.

Aim: Prader-Willi syndrome (PWS) is a rare genetic disorder characterized by intellectual disability, behavioral problems, and hypothalamic dysfunction combined with specific dysmorphisms. PWS is associated with limited adult height and an unfavorable body composition. Premature pubarche is frequent. Data on adult height after long-term growth hormone therapy are limited, as are data on the development of body composition during growth hormone therapy and the role of premature pubarche. This study aimed to explore the effect of long-term growth hormone therapy on adult height and body composition at adult height in children with PWS. Methods: This was a single-center, retrospective descriptive study involving 24 boys and 20 girls with genetically confirmed PWS. All participants began growth hormone therapy in early childhood until they reached adult height (AH). The children received internationally standardized growth hormone therapy. The primary outcome measures were AH, lean mass (LM), and fat mass (FM), as determined by dual-energy X-ray absorptiometry. Results: Adult height was 172.4 cm (-0.87 SD) in males and 160 cm (-0.90 SD) in females. There was no difference between children with or without premature pubarche. At adult height, LM was normal, but FM was increased in both males and females. Conclusion: Boys with PWS reached a normal height compared to their families; in girls, AH was just below the target height. AH did not differ between children with or without premature pubarche. LM was normal but should probably be higher, given the overweight, and FM was still increased after long-term growth hormone therapy.

Context Prader-Labhart-Willi syndrome (PWS) is a rare genetic disorder characterized by intellectual disability, behavioural problems, and hypothalamic dysfunction combined with specific dysmorphisms. In PWS, growth hormone treatment is given primarily to improve body composition, yet lean body mass (LBM) does not normalize. Male hypogonadism is frequent in PWS and becomes evident during puberty. While LBM increases in normal boys during puberty, it is not known whether LBM and muscle mass concomitantly increase in PWS during spontaneous or induced puberty. Objective To describe the peripubertal increment in muscle mass in boys with PWS undergoing growth hormone treatment. Design Single-center, retrospective descriptive study, using data from 4 years before until 4 years after onset of puberty. Setting Primary referral centre for PWS. Patients Thirteen boys diagnosed with genetically proven PWS. The mean age at onset of puberty was 12.3 years; the mean observation period before (after) onset of puberty was 2.9 (3.1) years. Intervention Puberty was induced upon pubertal arrest. All boys received internationally standardized growth hormone treatment. Main Outcome Measure Lean mass index (LMI) determined by dual energy X-ray absorptiometry. Results LMI increased by 0.28 kg/m² per year before puberty and by 0.74 kg/m² per year after the onset of puberty. The time before puberty explained less than 10% of the variation in LMI, whereas the time after puberty onset explained about 25%. Conclusion Boys with PWS showed a recognizable increment in LMI during both spontaneous and induced puberty compared with the prepubertal phase, which was within the trajectories of normal boys. Therefore, timely testosterone substitution in the absence or at arrest of puberty during growth hormone treatment is important to optimize peak LBM in PWS.

Prader-Labhart-Willi syndrome (PWS) is a rare genetic disorder characterized by intellectual disability, behavioural problems, hypothalamic dysfunction and specific dysmorphisms. Hypothalamic dysfunction causes dysregulation of energy balance and endocrine deficiencies, including hypogonadism. Although hypogonadism is prevalent in males and females with PWS, knowledge about this condition is limited. In this review, we outline the current knowledge on the clinical, biochemical, genetic and histological features of hypogonadism in PWS and its treatment. This was based on current literature and the proceedings and outcomes of the International PWS annual conference held in November 2019. We also present our expert opinion regarding the diagnosis, treatment, care and counselling of children and adults with PWS-associated hypogonadism. Finally, we highlight additional areas of interest related to this topic and make recommendations for future studies.

Background: Novel height, weight and body mass index (BMI) references for children in Switzerland reveal an increase in BMI compared to former percentile curves. This trend may be the result of children with parents originating from Southern European countries having a higher risk of being overweight compared to their peers with parents of Swiss origin. We examined the association of generational, migration-related and socioeconomic factors on BMI in Switzerland and expect the results to lead to more targeted prevention programs. Methods: From contemporary cross-sectional data, we calculated subgroup-specific BMI percentiles for origin. Results for children of Swiss origin were compared with historical BMI data from Zurich. We tested for the association of overweight and obesity with origin and compared the distributions of BMI percentile ranks. Logistic regression analyses were applied to predict probabilities of being overweight or obese by origin and the Swiss neighborhood index of socioeconomic position (SSEP). Results: Compared to the BMI from two generations ago, the newly calculated BMI increased only slightly for children with both parents from Switzerland; 1.2% of these girls and 1.6% of these boys are obese. In the Swiss population, 13% of the children have parents from Southern Europe and the proportion of obesity is 57 and 42% in these boys and girls, respectively. Their BMI medians correspond to those of their parents’ countries of origin. For the probability of being overweight or obese, the SSEP differences are less important than the status of origin. Conclusion: We identified children with both parents from Southern Europe as the main influence driving the increase in BMI in Switzerland over the past 50 years. A differentiated consideration of the proportions of various migrant groups within cross-sectional samples is essential when monitoring BMI. Ignoring fluctuations can lead to false conclusions.

Background: In 2011, WHO growth curves replaced those of Prader and colleagues (First Zurich longitudinal study) in Switzerland. Aim: To present contemporary height-, weight- and body mass index (BMI)-for-age references reflecting children’s growth in modern Switzerland. Subjects and methods: Cross-sectional sample comprising 30,141 boys and girls aged 0–20 years measured between 2012 and 2019. Height, weight and BMI reference curves were created using the LMS method. Derived percentiles were compared with those of Prader, WHO and neighbouring countries. Results: Growth in the first 5 years is almost identical with Prader curves. Thereafter children are taller, yet their final height is only about 1 cm higher. Today’s children, in particular boys, are considerably heavier. In comparison with WHO growth references, Swiss children are taller from the second year until adulthood; the WHO 3rd percentiles lie about 4 cm below those of our updated references. Weight and BMI median percentiles from our sample are similar to those of WHO and higher than the Prader curves. However, the course of the 97th BMI percentile WHO curves extends well below the 97th percentile of the updated Swiss curves. Conclusion: This study provides contemporary reference data for assessing individual growth based on height, weight and BMI of Swiss children.

Current concepts of linear growth include genetic, endocrine and nutritional factors. Limited and controversial results exist regarding the effect of physical activity (PA) on linear growth. In 2009, we showed that PA promotes foot length in hypoactive children with Prader-Willi-Syndrome. In the present study we tested the hypothesis that PA related epiphyseal loading has a positive modulating effect on linear growth in healthy school children. In 99 healthy schoolchildren, we measured height, foot length and PA by tri-axial accelerometry. PA related epiphyseal loading was expressed as the product between mass (body weight) and acceleration (vector magnitude). Correlation between height, foot length and PA were calculated taking into account co-variables age, sex, parental height, lean and fat mass measured by DEXA. Height SDS (P<0.015, r=0.245) as well as foot length SDS (P<0.001, r=0.363) correlated with PA. Multiple linear regression models showed that muscle mass expressed by lean body mass has higher correlation with PA, height SDS and foot length SDS than fat mass. This study shows that physically less active children are shorter and have shorter feet. In analogy to the "muscle bone unit", we propose a "muscle epiphyseal unit" which regulates local bone growth as long as epiphyseal plates are still open.

Sustained treatment adherence, usually over long periods of time, is critical to the success of growth hormone (GH) therapy. However, adherence rates are often poor which may result in suboptimal clinical outcomes. The type of device used by patients to administer their GH can influence adherence. Offering patients a choice of device maximizes the chance of adherence to treatment. Multiple factors will influence a patient's choice of device, depending on individual priorities. This study evaluated the most preferred features of GH injection devices by parents using a web-based questionnaire and as assessed by their willingness to pay for specific device features. The results show that parents are willing to pay for device features facilitating ease of use.