title: Truncal fat distribution correlates with decreased vital capacity in Duchenne muscular dystrophy.
abstract: BACKGROUND
  Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder associated with progressive muscle weakness and respiratory failure. Oral corticosteroids are the mainstay of treatment, but are associated with obesity with a central distribution. This study is designed to determine the relationship between body mass index, central adiposity, and lung function in subjects with DMD.
  
  
  METHODS
  Retrospective fat distribution data was obtained in boys with DMD from studies using dual X-ray absorptiometry (DXA). Fat distribution data was reviewed at two tertiary academic institutions and compared with concurrent height, weight, body mass index (BMI), measures of lung function, and sleep study data when available. Truncal fat mass used as a measure of central adiposity.
  
  
  RESULTS
  Forty-four subjects (age 12.0 ± 3.4 years) were included. Mean BMI was 22.1 ± 5.9 kg/m(2) . Sixty-eight percent (30 patients) were on corticosteroid therapy. Truncal fat mass percentage was inversely correlated with forced vital capacity (% predicted FVC) (Pearson coefficient -0.37, P = 0.01). Linear regression showed that truncal fat distribution, but not total fat mass, age or corticosteroid use negatively predicted FVC (r(2)  = 0.24, P = 0.048). BMI had a positive effect (P = 0.04). However, fat distribution did not predict the rate of change of lung function in a smaller sample. Fat distribution, BMI, or age did not predict measures of sleep disordered breathing.
  
  
  CONCLUSIONS
  Truncal fat distribution is a significant predictor of lower vital capacity in boys with DMD, whereas BMI has a positive effect.
authors.affiliation: Yale New Haven Children's Hospital, Yale University, New Haven, Connecticut.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Canapari
authors.forename: Nick
authors.initials: N
authors.lastname: Barrowman
authors.forename: Lynda
authors.initials: L
authors.lastname: Hoey
authors.forename: Scott W
authors.initials: SW
authors.lastname: Walker
authors.forename: Elise
authors.initials: E
authors.lastname: Townsend
authors.forename: Brian S
authors.initials: BS
authors.lastname: Tseng
authors.forename: Sherri L
authors.initials: SL
authors.lastname: Katz
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D050218:Body Fat Distribution; D015992:Body Mass Index; D002648:Child; D006801:Humans; D016014:Linear Models; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000503:physiopathology*; D056128:Obesity, Abdominal / Q000503:physiopathology*; D012189:Retrospective Studies; D060726:Torso; D014797:Vital Capacity / Q000502:physiology*; D055815:Young Adult
keywords: adiposity; body mass index; muscular dystrophy; restrictive lung disease