title: Skeletal, cardiac, and smooth muscle failure in Duchenne muscular dystrophy.
abstract: The goals of this study were to describe the clinical course of skeletal, cardiac, and gastrointestinal muscle manifestations and trends in age at diagnosis and survival of Duchenne muscular dystrophy (DMD) patients. A retrospective cohort of 33 male patients with DMD, born between 1953 and 1983 and followed at the Mayo Clinic during their second decade of life, was studied. The mean age at DMD diagnosis was 4.6 years. Skeletal muscle weakness present in all patients at diagnosis progressed to wheelchair dependency in 32 patients (97%) by the age of 13 years (median age 10 years). Cardiac muscle failure developed in 5 patients (15%) (median age 21.5 years). Smooth muscle manifestations related to the digestive and urinary tracts occurred in 7 (21%) and 2 (6%) patients (median age 15 years), respectively. The gastrointestinal dilatations were primary in 2 patients or secondary to surgery or acute respiratory illness in 5 patients. By the end of the study period, 17 deaths had occurred (median age 17 years). Over time, there was a decrease in the time to DMD diagnosis (P = .05) but no significant change in survival (P = .44). Cardiac and smooth muscle manifestations occur late in the course of DMD. Clinical gastrointestinal symptoms related to smooth muscle function most often were secondary to surgery or a respiratory illness. In recent years, the diagnosis of DMD has been made at a younger age, but survival has not changed.
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Boland
authors.forename: P L
authors.initials: PL
authors.lastname: Silbert
authors.forename: R V
authors.initials: RV
authors.lastname: Groover
authors.forename: P C
authors.initials: PC
authors.lastname: Wollan
authors.forename: M D
authors.initials: MD
authors.lastname: Silverstein
mesh_terms: D000293:Adolescent; D000328:Adult; D002423:Cause of Death; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004064:Digestive System / Q000503:physiopathology; D005500:Follow-Up Studies; D005769:Gastrointestinal Motility / Q000502:physiology; D005772:Gastrointestinal Transit / Q000502:physiology; D006333:Heart Failure / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009130:Muscle, Smooth / Q000503:physiopathology*; D009136:Muscular Dystrophies / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology*; D012189:Retrospective Studies; D015996:Survival Rate; D014551:Urinary Tract / Q000503:physiopathology; D014563:Urodynamics / Q000502:physiology