title: The 6-minute walk test and other endpoints in Duchenne muscular dystrophy: longitudinal natural history observations over 48 weeks from a multicenter study.
abstract: BACKGROUND
  Duchenne muscular dystrophy (DMD) subjects ≥5 years with nonsense mutations were followed for 48 weeks in a multicenter, randomized, double-blind, placebo-controlled trial of ataluren. Placebo arm data (N = 57) provided insight into the natural history of the 6-minute walk test (6MWT) and other endpoints.
  
  
  METHODS
  Evaluations performed every 6 weeks included the 6-minute walk distance (6MWD), timed function tests (TFTs), and quantitative strength using hand-held myometry.
  
  
  RESULTS
  Baseline age (≥7 years), 6MWD, and selected TFT performance are strong predictors of decline in ambulation (Δ6MWD) and time to 10% worsening in 6MWD. A baseline 6MWD of <350 meters was associated with greater functional decline, and loss of ambulation was only seen in those with baseline 6MWD <325 meters. Only 1 of 42 (2.3%) subjects able to stand from supine lost ambulation.
  
  
  CONCLUSIONS
  Findings confirm the clinical meaningfulness of the 6MWD as the most accepted primary clinical endpoint in ambulatory DMD trials.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of California Davis School of Medicine, Davis, California, 95817, USA.
authors.forename: Craig M
authors.initials: CM
authors.lastname: McDonald
authors.forename: Erik K
authors.initials: EK
authors.lastname: Henricson
authors.forename: R Ted
authors.initials: RT
authors.lastname: Abresch
authors.forename: Julaine M
authors.initials: JM
authors.lastname: Florence
authors.forename: Michelle
authors.initials: M
authors.lastname: Eagle
authors.forename: Eduard
authors.initials: E
authors.lastname: Gappmaier
authors.forename: Allan M
authors.initials: AM
authors.lastname: Glanzman
authors.forename: Robert
authors.initials: R
authors.lastname: Spiegel
authors.forename: Jay
authors.initials: J
authors.lastname: Barth
authors.forename: Gary
authors.initials: G
authors.lastname: Elfring
authors.forename: Allen
authors.initials: A
authors.lastname: Reha
authors.forename: Stuart
authors.initials: S
authors.lastname: Peltz
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D004576:Electromyography; D005080:Exercise Test; D005938:Glucocorticoids / Q000627:therapeutic use; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000188:drug therapy / Q000503:physiopathology*; D019370:Observation; D017063:Outcome Assessment, Health Care; D010069:Oxadiazoles / Q000627:therapeutic use; D011237:Predictive Value of Tests; D013997:Time Factors; D016138:Walking / Q000502:physiology*
chemical_list: D005938:Glucocorticoids; D010069:Oxadiazoles; C515878:ataluren
keywords: 6-minute walk test; Duchenne muscular dystrophy; ambulation; dystrophinopathy; myometry; natural history; prediction of loss of function; timed function tests