Sleep-disordered breathing in Australian children with Prader-Willi syndrome following initiation of growth hormone therapy.

AIM: In children with Prader-Willi syndrome (PWS), growth hormone (GH) improves height and body composition; however, may be associated with worsening sleep-disordered breathing (SDB). Some studies have reported less SDB after GH initiation, but follow-up with polysomnography is still advised in most clinical guidelines. METHODS: This retrospective, multicentre study, included children with PWS treated with GH at seven PWS treatment centres in Australia over the last 18 years. A paired analysis comparing polysomnographic measures of central and obstructive SDB in the same child, before and after GH initiation was performed with Wilcoxon signed-rank test. The proportion of children who developed moderate/severe obstructive sleep apnoea (OSA) was calculated with their binomial confidence intervals. RESULTS: We included 112 patients with available paired data. The median age at start of GH was 1.9 years (range 0.1-13.5 years). Median obstructive apnoea hypopnoea index (AHI) at baseline was 0.43/h (range 0-32.9); 35% had an obstructive AHI above 1.0/h. Follow-up polysomnography within 2 years after the start of GH was available in 94 children who did not receive OSA treatment. After GH initiation, there was no change in central AHI. The median obstructive AHI did not increase significantly (P = 0.13), but 12 children (13%, CI95% 7-21%) developed moderate/severe OSA, with clinical management implications. CONCLUSIONS: Our findings of a worsening of OSA severity in 13% of children with PWS support current advice to perform polysomnography after GH initiation. Early identification of worsening OSA may prevent severe sequelae in a subgroup of children.

Clinical and lung function outcomes in a cohort of children with severe asthma.

BACKGROUND: Uncontrolled severe asthma in children is burdensome and challenging to manage. This study aims to describe outcomes in children with uncontrolled severe asthma managed in a nurse-led severe asthma clinic (SAC). METHODS: This retrospective analysis uses data collected from children referred by a paediatric respiratory specialist to a nurse-led SAC for uncontrolled severe asthma between 2014 and 2019. The pre-clinical assessments included a home visit to assess modifiable factors that could be addressed to improve control. A comprehensive lung function analysis was conducted at each visit. Interventions were personalised and included biologic agents. Statistical analysis was performed using nonparametric, two-tailed Mann-Whitney U-test, the parametric Student's t-test, or analysis of variance (ANOVA) as appropriate. RESULTS: Twenty-three children with a median age of 12 years were seen once, and 16 were followed up. Compared to a non-asthmatic (NA) and asthmatic (A) age-matched cohort, children with severe asthma (SA) had a lower FEV1, and FVC% predicted before and after bronchodilator inhalation, and a higher mean Lung Clearance Index [LCI] (10.5 [SA] versus 7.3 [NA] versus 7.6 [A], p = 0.003). Almost 80% of children with SA had an abnormal LCI, and 48% had a reduced FEV1% at the first SAC visit. Asthma control and FEV1% predicted significantly improved at a follow-up visit, while LCI remained abnormal in the majority of children (83%). CONCLUSION: Over time, many children with severe asthma showed improved clinical outcomes and lung function while lung ventilation inhomogeneities persisted. Future appropriately controlled studies are required to determine if a nurse-led multidisciplinary SAC is associated with better outcomes.

Requirements for improving health and well-being of children with Prader-Willi syndrome and their families.

Prader-Willi syndrome (PWS) is a rare genetic condition with multi-system involvement. The literature was reviewed to describe neurodevelopment and the behavioural phenotype, endocrine and metabolic disorders and respiratory and sleep functioning. Implications for child and family quality of life were explored. Challenging behaviours contribute to poorer well-being and quality of life for both the child and caregiver. Recent evidence indicates healthy outcomes of weight and height can be achieved with growth hormone therapy and dietary restriction and should be the current target for all individuals with PWS. Gaps in the literature included therapies to manage challenging behaviours, as well as understanding the effects of growth hormone on respiratory and sleep function. New knowledge regarding the transition of children and families from schooling and paediatric health services to employment, accommodation and adult health services is also needed. Developing a national population-based registry could address these knowledge gaps and inform advocacy for support services that improve the well-being of individuals with PWS and their families.