Prevalence of Comorbid Conditions in 222 Hungarian Patients with Phenylketonuria

Background: Phenylketonuria (PKU) is considered one of the greatest success stories of modern medicine. With the implementation of newborn screening and early introduction of a low phenylalanine (Phe) diet, patients with PKU are able to reach adulthood without major neurocognitive deficits observed in untreated individuals. However, recent studies have suggested a higher incidence of specific comorbid conditions, such as overweight, hypertension, and diabetes, in adult PKU patients. In this study, we aimed to evaluate the prevalence of comorbid conditions in Hungarian PKU patients who are treated at a single center in Hungary.
Methods: We conducted a retrospective single-center study that included PKU and hyperphenylalaninemia (HPA) patients who attended follow-ups at the adult Inherited Metabolic Disorders (IEM) center at Semmelweis University Budapest. We assessed anthropometric parameters, comorbid conditions, and metabolic control.
Results: A total of 222 patients (mean age 35.1 ± 8.3 SD, male: 97, female: 125) attended medical follow-ups at least once since 2011. The cohort included 29 (13%) patients diagnosed with HPA and 193 (87%) with classical PKU (184 early-treated and 9 late-diagnosed). Average Phe level was 610,9 ± 293 µmol/L. The average body mass index (BMI) was 26.0 ± 6.0 SD kg/m² (male patients: 25.9 ± 6.4, female: 26.0 ± 5.6). Overweight was present in 108 patients (48.6%, male: 50, female: 58), obesity in 49 patients (22%, male: 21, female: 28), hypertension in 27 patients (male: 14, female: 13), and type 2 diabetes in 6 female patients.
Conclusion: Our findings demonstrate a similarly high prevalence of overweight and obesity in both male and female PKU patients. The incidence of hypertension was comparable; however, diabetes was only observed in female patients, with an overall high incidence considering the age of the cohort. Therefore, continued evaluation of comorbidities in these patients is necessary, despite adequate metabolic control.