Assessing sleep habits in school-aged children with phenylketonuria: a comparative study

Phenylketonuria (PKU) is an autosomal recessive metabolic disorder characterized as deficiencies in phenylalanine hydroxylase, leading to neurotoxic effects and neurodevelopmental challenges. Sleep, crucial for cognitive and behavioral development, remains underexplored in PKU populations. This study evaluates sleep characteristics and influencing factors in school-aged children with PKU compared to those with hyperphenylalaninemia (HPA) and healthy controls. A total of 101 children aged 5-10 years participated: 37 with PKU, 31 with HPA, and 33 healthy controls. Sleep quality and disturbances were assessed using the Children's Sleep Habits Questionnaire (CSHQ) and parent-reported data. Additional factors, including phenylalanine levels and sleep hygiene practices, were analyzed. Despite no significant differences in total CSHQ scores across groups, children with PKU exhibited unique patterns, such as being less likely to awaken by himself or herself. Phenylalanine levels showed no significant correlations with overall sleep characteristics, except for an association with reduced sleep anxiety. Distinct sleep hygiene influences emerged in the HPA and control groups, while no such relationships were observed in PKU. This study underscores the complexity of sleep disturbances in PKU, highlighting the need for future research integrating biological, behavioral, and environmental factors. Identifying determinants of sleep problems will aid in developing tailored interventions to enhance the quality of life for patients with PKU. What is known: • Children with PKU, in addition to the risks associated with chronic illness, may be more susceptible to sleep disturbances due to metabolic and neurochemical imbalances. • Prior studies on PKU and sleep have mainly focused on adult populations, with limited data available for school-aged children. What is new: • The sleep characteristics of PKU, HPA, and healthy controls were generally similar, except for awakening by themselves. • Distinct sleep hygiene influences were identified in the HPA and control groups, while no such associations were observed in the PKU group, highlighting the need for a broader perspective to explore alternative biological, behavioral, and environmental factors affecting sleep regulation in PKU.