title: Sustained benefit after 2 years of growth hormone on body composition, fat utilization, physical strength and agility, and growth in Prader-Willi syndrome.
abstract: BACKGROUND
  Obesity and hypotonia in children with Prader-Willi syndrome (PWS) are accompanied by abnormal body composition resembling a growth hormone (GH)-deficient state. Hypothalamic dysfunction in PWS includes decreased GH secretion, suggesting a possible therapeutic role for GH treatment. Although recent studies have demonstrated short-term benefits of treatment with GH, a critical question is whether beneficial changes persist or wane with prolonged therapy.
  
  
  OBJECTIVE
  Effects of 24 months of GH treatment (1 mg/m(2)/d) on growth, body composition, strength and agility, pulmonary function, resting energy expenditure, and fat utilization were assessed in 35 children with PWS. Percent body fat, lean muscle mass, and bone mineral density were measured by dual-energy x-ray absorptiometry. Indirect calorimetry was used to determine resting energy expenditure and to calculate the respiratory quotient.
  
  
  RESULTS
  Compared with baseline evaluations, increased height velocity (SD score -1.1 +/- 2.5 to 2.2 +/- 2.3; P <. 001), reduced percent body fat (46.4% +/- 8.4% to 40.3% +/- 10.0%, P <.001), and improved respiratory muscle function and physical strength and agility (sit-ups, weight-lifts, running speed, and broad jump; P <.01) were observed after 24 months of GH treatment. A decline in respiratory quotient (0.81 +/- 0.07 to 0.75 +/- 0.06; P <. 01) and a trend toward increased resting energy expenditure were also observed. Changes in response to GH occurred predominantly during the initial 12 months of GH therapy.
  
  
  CONCLUSIONS
  Children with PWS had sustained increases in lean body mass, decreases in percent body fat, improvements in physical strength and agility, and increased fat oxidation after 24 months of GH therapy. However, between 12 and 24 months, the growth rate slowed. Consequently, encouraging initial results require even more prolonged study to draw conclusions regarding the long-term value of GH therapy in changing body composition in children with PWS.
authors.affiliation: Department of Pediatrics, St. Louis University, Cardinal Glennon Children's Hospital, MO 63104, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Myers
authors.forename: A L
authors.initials: AL
authors.lastname: Carrel
authors.forename: B Y
authors.initials: BY
authors.lastname: Whitman
authors.forename: D B
authors.initials: DB
authors.lastname: Allen
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000886:Anthropometry; D001823:Body Composition; D015519:Bone Density; D002648:Child; D004734:Energy Metabolism; D005500:Follow-Up Studies; D019382:Human Growth Hormone / Q000627:therapeutic use*; D006801:Humans; D010809:Physical Fitness; D011218:Prader-Willi Syndrome / Q000188:drug therapy* / Q000503:physiopathology*; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
chemical_list: D019382:Human Growth Hormone