title: Quality of dietary control in phenylketonuric patients and its relationship with general intelligence.
abstract: OBJECTIVE
  Assessment of the quality of dietary treatment of phenylketonuria (PKU) patients and investigation of its relationship with the general intelligence of the patients.
  
  
  METHODS
  Cross-sectional and longitudinal study of 105 PKU treated patients. The index of dietary control (IDC) was calculated as the phenylalanine (Phe) data reduction in half-year medians and the mean of all medians throughout the patient's life. We calculated four different IDCs related to age: IDC-A (< 6 years), IDC-B (6-12 years), IDC-C (13-18 years) and IDC-D (> 18 years). To evaluate the fluctuation of Phe values we calculated the standard error of the estimate of the regression of Phe concentration over age. Development quotient was calculated with the Brunet-Lezine test (< 4 years). Intelligence quotient was evaluated with the Kaufman Bit Intelligence Test (K-Bit), Wechsler Intelligence Scale for Children-Revised (WISC-R) and Wechsler Adult Intelligence Scale Third Edition (WAIS III).
  
  
  RESULTS
  Cross-sectional study: The IDC in age groups were significantly different and so were the number of patients with good, acceptable and poor IDC related to age (p < 0.001). Sampling frequency was good in 72, acceptable in 23 and poor in 10 patients. The general intelligence (101 +/- 10) correlated negatively with the IDC (p < 0.0001) and Phe fluctuations (p < 0.004). Longitudinal study: Significant differences were observed between the IDC through the patients' lifetime except in the adolescent/adult period.
  
  
  CONCLUSIONS
  85% of PKU patients showed good/acceptable quality of dietary control. General intelligence correlates with the IDC at all ages, which highlights the importance of good control to achieve good prognosis.
authors.affiliation: Department of Biochemistry, Hospital San Joan de Déu, University of Barcelona, Barcelona, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Vilaseca
authors.forename: N
authors.initials: N
authors.lastname: Lambruschini
authors.forename: Lilianne
authors.initials: L
authors.lastname: Gómez-López
authors.forename: A
authors.initials: A
authors.lastname: Gutiérrez
authors.forename: E
authors.initials: E
authors.lastname: Fusté
authors.forename: R
authors.initials: R
authors.lastname: Gassió
authors.forename: R
authors.initials: R
authors.lastname: Artuch
authors.forename: J
authors.initials: J
authors.lastname: Campistol
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D007360:Intelligence; D008137:Longitudinal Studies; D008297:Male; D010661:Phenylketonurias / Q000178:diet therapy* / Q000523:psychology*; D055815:Young Adult