Whole body composition analysis by the BodPod air-displacement plethysmography method in children with phenylketonuria shows a higher body fat percentage.
BACKGROUND
Phenylketonuria (PKU) causes irreversible central nervous system damage unless a phenylalanine (PHE) restricted diet with amino acid supplementation is maintained. To prevent growth retardation, a protein/amino acid intake beyond the recommended dietary protein allowance is mandatory. However, data regarding disease and/or diet related changes in body composition are inconclusive and retarded growth and/or adiposity is still reported. The BodPod whole body air-displacement plethysmography method is a fast, safe and accurate technique to measure body composition.


OBJECTIVE
To gain more insight into the body composition of children with PKU.


METHODS
Patients diagnosed with PKU born between 1991 and 2001 were included. Patients were identified by neonatal screening and treated in our centre. Body composition was measured using the BodPod system (Life Measurement Incorporation©). Blood PHE values determined every 1-3 months in the year preceding BodPod analysis were collected. Patients were matched for gender and age with data of healthy control subjects. Independent samples t tests, Mann-Whitney and linear regression were used for statistical analysis.


RESULTS
The mean body fat percentage in patients with PKU (n = 20) was significantly higher compared to healthy controls (n = 20) (25.2% vs 18.4%; p = 0.002), especially in girls above 11 years of age (30.1% vs 21.5%; p = 0.027). Body fat percentage increased with rising body weight in patients with PKU only (R = 0.693, p = 0.001), but did not correlate with mean blood PHE level (R = 0.079, p = 0.740).


CONCLUSIONS
Our data show a higher body fat percentage in patients with PKU, especially in girls above 11 years of age.
Albersen
Monique
M
Department of Metabolic and Endocrine Diseases, Wilhelmina Children's Hospital, University Medical Centre Utrecht, Huispost KC02.069.1, Lundlaan 6, 3584 EA Utrecht, The Netherlands.
Bonthuis
Marjolein
M
de Roos
Nicole M
NM
van den Hurk
Dorine A M
DA
Carbasius Weber
Ems
E
Hendriks
Margriet M W B
MM
de Sain-van der Velden
Monique G M
MG
de Koning
Tom J
TJ
Visser
Gepke
G
D050154:Adiposity; D000293:Adolescent; D000367:Age Factors; D000596:Amino Acids / Q000008:administration & dosage; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D016022:Case-Control Studies; D002648:Child; D018753:Diet, Protein-Restricted; D004867:Equipment Design; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D016014:Linear Models; D008297:Male; D015997:Neonatal Screening; D010649:Phenylalanine / Q000097:blood; D010661:Phenylketonurias / Q000097:blood / Q000175:diagnosis / Q000178:diet therapy / Q000503:physiopathology*; D010993:Plethysmography, Whole Body / Q000295:instrumentation / Q000379:methods*; D011237:Predictive Value of Tests; D012737:Sex Factors; D015430:Weight Gain
D000596:Amino Acids; D015415:Biomarkers; D010649:Phenylalanine