title: Longitudinal quality of life analysis in a phenylketonuria cohort provided sapropterin dihydrochloride.
abstract: BACKGROUND
  Sapropterin dihydrochloride effectively lowers plasma phenylalanine (Phe) for at least a third of phenylketonuria (PKU) patients, with potential for increased dietary Phe tolerance and decreased medical food requirement.
  
  
  OBJECTIVE
  To investigate long-term quality of life (QOL) in patients with phenylketonuria (PKU) who took sapropterin (BH4, Kuvan®) for up to one year.
  
  
  METHODS
  37 PKU patients, ages 10-49 years, were asked to complete a PKU-specific self-report QOL questionnaire (QOLQ) at baseline, 1, 4, 8, and 12 months. Questions were scored on a 5-point Likert scale under 5 sub-sections measuring Impact, Worries, Satisfaction, Support, and General wellbeing in relation to PKU. Responders with a plasma Phe decrease ≥ 15% after 1 month on sapropterin remained on the drug; Nonresponders ceased sapropterin after the trial month. Responders able to relax medical diet and maintain plasma Phe control were classified as Definitive; Responders unable to relax medical diet were classified as Provisional. All patients were routinely monitored by a registered dietitian. Data was analyzed in SPSS 19.0 using regression techniques.
  
  
  RESULTS
  Of 17 Responders, 11 could maintain adequate Phe control on a less restrictive diet. One year mean Impact sub-score trends improved significantly for all sapropterin response groups, with greatest improvement among Definitive Responders (p < 0.0001). Satisfaction sub-scores also improved for Definitive Responders (p = 0.001). Trends for Total QOL score improved significantly over time for both Definitive (p = 0.001) and Provisional Responders (p = 0.028). Improvements in Definitive Responder scores were associated with increased Phe tolerance (Impact: p < 0.0001, Satisfaction: p = 0.022, Total QOL: p = 0.005) and MF adjustment (Satisfaction: p = 0.014, Total QOL: p = 0.026). Other sub-section scores remained steady, unaffected by sapropterin response or diet modification.
  
  
  CONCLUSIONS
  Increased Phe tolerance and reduced MF requirement in sapropterin Definitive Responders improves QOL perception across one year, specifically for life impact and satisfaction.
authors.forename: Teresa D
authors.initials: TD
authors.lastname: Douglas
authors.forename: Usha
authors.initials: U
authors.lastname: Ramakrishnan
authors.forename: Julie A
authors.initials: JA
authors.lastname: Kable
authors.affiliation: Metabolic Nutrition Program, Division of Medical Genetics, Emory Department of Human Genetics, 2165 North Decatur Road, Decatur, GA 30033, USA. rsingh@emory.edu.
authors.forename: Rani H
authors.initials: RH
authors.lastname: Singh
mesh_terms: D000293:Adolescent; D000328:Adult; D001708:Biopterins / Q000031:analogs & derivatives* / Q000627:therapeutic use; D002648:Child; D005260:Female; D005845:Georgia; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010661:Phenylketonurias / Q000178:diet therapy / Q000188:drug therapy*; D011788:Quality of Life / Q000523:psychology*; D057566:Self Report; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D001708:Biopterins; C003402:sapropterin