Early dietary treated patients with phenylketonuria can achieve normal growth and body composition

BackgroundIn the past, overtreatment may have resulted in growth impairment in patients with phenylketonuria.ObjectiveThe paper aims to investigate height and body composition in early treated patients with phenylketonuria who were diagnosed between 1981 and 2008.DesignA cross-sectional study of 89 patients with phenylketonuria and 78 controls aged (mean ± SD, in years) 14.4 ± 6.6 and 15.9 ± 7.1, respectively, was undertaken, including anthropometric and body composition evaluation using bioelectrical impedance. Median Phe concentrations in the last year before study enrolment were used as a measure of metabolic control. Natural protein and amino acid mixture intakes were recorded in patients.ResultsNo statistically significant differences were found on height z-scores between patients and controls aged less than 19 years (p = 0.301), although all patients with classical phenylketonuria revealed negative height z-scores, resulting in a mean ± SD of − 0.65 ± 0.41. Among participants aged 19 years or more, median (p25–p75) of height was significantly higher in controls [168.0 cm (159.2–174.8)] than in patients [160.5 cm (151.9–167.5)] (p = 0.017). No significant differences were found between patients and controls regarding fat mass, fat free mass, muscular mass, body cell mass index and phase angle.ConclusionOur results suggest that early and continuously treated patients with phenylketonuria born after 1992 can achieve normal growth and body composition, although the negative height z-score in patients with classical phenylketonuria strengthens the continuous need to optimize the quality of their protein intake.