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2022 22 SET

Progression of Obstructive Sleep Apnea Syndrome in Prader–Willi Syndrome

Sleep-disordered breathing (SDB) is one of the most common comorbidities in children with Prader-Willi Syndrome (PWS). In the first years of life, these patients are mostly affected by central apneas (CA), while in older children sleep apnea syndrome (OSAS) gradually appeared linked to obesity, craniofacial conformation, hypotonia and scoliosis. Therapy for these patients is often debated and watchful waiting is also contemplated as a possible strategy. However, there is a lack of data on the long-term progression of OSAS in patients with PWS that can help us determine an appropriate management strategy.

Wong et al., in this recent publication of June 2022, describe a retrospective study that collected and analyzed data regarding the consecutive polysomnography (PSG) data from 2009 to 2017 in a group of 48 children with PWS. Among the 48 patients, 2 received CPAP treatment, 1 received adenotonsillectomy, and 23 had only 1- or 2-year longitudinal data. Therefore, 22 patients (84 PSG studies) who underwent at least 3 years of follow-up were included in this study, 10 males and 12 females with a mean age of 11.7 years. At the last PSG performed 20 patients had OSAS (38.9% had mild OSAS, 38.9% moderate, 16.7% severe) and during the follow-up only 2 children with OSAS had a spontaneous resolution of the problem. These results are consistent with previous studies: PWS patients presenting features such as obesity, facial dysmorphism, micrognathia and hypotonia are a population extremely at risk of OSAS. Due to the poor spontaneous resolution over time, the study suggests that a watchful waiting approach is probably not the method of choice in these patients. The authors then analyzed the data concerning the body mass index (BMI) highlighting a gradual increase over time without a significant consensual increase in the apnea index. However, analyzing the data by adjusting for age, sex, genotype, GH therapy and the BMI z-score, it results that BMI z-score and the genotype without deletion represented two risk factors for a worst index of obstructive apneas / hypopneas (OAHI) and, therefore, for OSAS. Regarding the type of genotype, only 5 patients in the study presented the form without deletion and, therefore, data are extremely poor to reach definitive conclusions.

Despite the limitations of a retrospective study with a small cohort, this paper confirms the importance that SDB have in PWS patients. From the follow-up of these patients, the authors don’t observe a significant spontaneous resolution of OSAS over time and, therefore, don’t recommend a watchful waiting approach. Finally, from these data emerges a correlation between obesity and type of genotype with the risk of developing OSAS more significant. If the results on the genotype are still weak, weight control certainly remains one of the strategies to be addressed in these patients.


Bibliography

Wong SB, Yang MC, Tzeng IS, Tsai WH, Lan CC, Tsai LP. Progression of Obstructive Sleep Apnea Syndrome in Pediatric Patients with Prader-Willi Syndrome. Children (Basel). 2022 Jun 17;9(6):912. doi: 10.3390/children9060912.

Article by Mara Lelii