title: Responses to Fasting and Glucose Loading in a Cohort of Well Children with Spinal Muscular Atrophy Type II.
abstract: OBJECTIVE
  To examine the impact of fasting and glucose tolerance on selected metabolic variables in children with spinal muscular atrophy (SMA) type II in a well state, secondary to reports of glucose regulation abnormalities in SMA.
  
  
  METHODS
  In this prospective pilot study, 6 children aged 7-11 years with SMA type II participated in an oral glucose tolerance test and a supervised medical fast during 2 overnight visits at the University of Utah. At baseline, a dual-energy x-ray absorptiometry scan was performed to determine body composition. Laboratory test results were obtained at baseline and in response to the respective interventions. Data analysis was descriptive. Prefasting and postfasting data were evaluated using the Wilcoxon signed-rank test.
  
  
  RESULTS
  Based on the dual-energy x-ray absorptiometry scan, all 6 children were variably obese at baseline. All 6 exhibited hyperinsulinemia, and 3 of 6 met formal American Diabetes Association criteria for impaired glucose tolerance. According to homeostatic insulin resistance calculations, 5 of the 6 participants were insulin-resistant. All 6 participants tolerated a monitored fast for 20 hours without hypoglycemia (blood glucose <54 mg/dL). Free fatty acid levels increased significantly from prefasting to postfasting, whereas levels of several plasma amino acids decreased significantly during fasting.
  
  
  CONCLUSIONS
  Children with SMA type II defined as obese using objective variables are at increased risk for impaired glucose tolerance regardless of whether or not they visually appear obese. Further studies are needed to determine the prevalence of impaired glucose tolerance and tolerance for fasting within the broader heterogeneous SMA population and to develop appropriate guidelines for intervention.
authors.affiliation: Pediatric Motor Disorders Research Program, Department of Neurology, University of Utah, Salt Lake City, UT; Division of Nutrition, University of Utah, Salt Lake City, UT. Electronic address: becky.hurst@utah.edu.
authors.forename: Rebecca Hurst
authors.initials: RH
authors.lastname: Davis
authors.affiliation: Pediatric Motor Disorders Research Program, Department of Neurology, University of Utah, Salt Lake City, UT.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Miller
authors.affiliation: Pediatric Motor Disorders Research Program, Department of Neurology, University of Utah, Salt Lake City, UT.
authors.forename: Ren Zhe
authors.initials: RZ
authors.lastname: Zhang
authors.affiliation: Pediatric Motor Disorders Research Program, Department of Neurology, University of Utah, Salt Lake City, UT. Electronic address: kswoboda@mgh.harvard.edu.
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Swoboda
mesh_terms: D015502:Absorptiometry, Photon; D001786:Blood Glucose / Q000378:metabolism*; D002648:Child; D005215:Fasting / Q000502:physiology*; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D009765:Obesity / Q000097:blood / Q000175:diagnosis / Q000209:etiology*; D010865:Pilot Projects; D011446:Prospective Studies; D012307:Risk Factors; D014897:Spinal Muscular Atrophies of Childhood / Q000097:blood* / Q000150:complications
chemical_list: D001786:Blood Glucose