Transitioning into Adulthood with PKU: The Role of Diet, Coping Strategies, and Quality of Life in Adolescents and Young Adults

Background: Phenylketonuria (PKU) is a rare metabolic disorder requiring lifelong dietary treatment. Adolescents and young adults face unique challenges in managing the condition, often compromising adherence and psychological well-being. This study aimed to explore coping strategies used by patients to manage their condition and their associations with dietary adherence, PKU-related symptoms, and quality of life (QoL) in young individuals with PKU. Methods: A cross-sectional study was conducted with 21 adolescents and young adults (13–25 years) with classical PKU, followed at the Unit of Inherited Metabolic Diseases in Padua, Italy. Participants completed questionnaires assessing dietary adherence, QoL, and coping. Biochemical data were collected from medical records. Results: Only 57.1% fully adhered to the diet; social barriers like embarrassment and school/work environments hindered adherence. Adolescents reported more irritability and concentration difficulties, while young adults reported greater fatigue. QoL was moderately impacted. Avoidance coping was more frequent in young adults and correlated with irritability and lower QoL. Transcendence-oriented coping was linked to fewer insomnia symptoms. Conclusions: Coping strategies influence symptom experience and QoL in PKU. Integrating psychological support and personalized care into routine treatment is essential to improve adherence and support patients through the transition to adulthood.