A New Perspective on Drugs for Duchenne Muscular Dystrophy: Proposals for Better Respiratory Outcomes and Improved Regulatory Pathways.

New drugs for Duchenne muscular dystrophy (DMD) are emerging rapidly. However, we and others believe these drugs are achieving regulatory approval prematurely. It is the cardiorespiratory complications of DMD that cause the disease's major morbidities and that determine survival.

Cardiopulmonary phenotypic discordance is common in Duchenne muscular dystrophy.

Objective: To determine the prevalence of discordant cardiopulmonary function among patients with Duchenne muscular dystrophy (DMD) in our clinic.

Methods: Retrospective chart review from 1999 to 2017.

Inclusion Criteria: DMD patients age ≥ 18 years, alive, with discordant cardiopulmonary function.

Respiratory Management of the Patient With Duchenne Muscular Dystrophy.

In 2010, Care Considerations for Duchenne Muscular Dystrophy, sponsored by the Centers for Disease Control and Prevention, was published in , and in 2018, these guidelines were updated. Since the publication of the first set of guidelines, survival of individuals with Duchenne muscular dystrophy has increased. With contemporary medical management, survival often extends into the fourth decade of life and beyond.

Muscular Dystrophies.

Muscular dystrophies represent a complex, varied, and important subset of neuromuscular disorders likely to require the care of a pulmonologist. The spectrum of conditions encapsulated by this subset ranges from severe and fatal congenital muscular dystrophies with onset in infancy to mild forms of limb and girdle weakness with onset in adulthood and minimal respiratory compromise. The list and classification of muscular dystrophies are undergoing near-constant revision, based largely on new insights from genetics and molecular medicine.

Diagnosis and management of Duchenne muscular dystrophy, part 2: respiratory, cardiac, bone health, and orthopaedic management.

A coordinated, multidisciplinary approach to care is essential for optimum management of the primary manifestations and secondary complications of Duchenne muscular dystrophy (DMD). Contemporary care has been shaped by the availability of more sensitive diagnostic techniques and the earlier use of therapeutic interventions, which have the potential to improve patients' duration and quality of life. In part 2 of this update of the DMD care considerations, we present the latest recommendations for respiratory, cardiac, bone health and osteoporosis, and orthopaedic and surgical management for boys and men with DMD.

Associations between timing of corticosteroid treatment initiation and clinical outcomes in Duchenne muscular dystrophy.

The long-term efficacy of corticosteroid treatment and timing of treatment initiation among Duchenne muscular dystrophy (DMD) patients is not well-understood. We used data from a longitudinal, population-based DMD surveillance program to examine associations between timing of treatment initiation (early childhood [before or at age 5 years], late childhood [after age 5 years], and naïve [not treated]) and five clinical outcomes (age at loss of ambulation; ages at onset of cardiomyopathy, scoliosis, and first fracture; and pulmonary function). Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using survival analysis.

Respiratory Care Received by Individuals With Duchenne Muscular Dystrophy From 2000 to 2011.

Background: Duchenne muscular dystrophy (DMD) causes progressive respiratory muscle weakness and decline in function, which can go undetected without monitoring. DMD respiratory care guidelines recommend scheduled respiratory assessments and use of respiratory assist devices. To determine the extent of adherence to these guidelines, we evaluated respiratory assessments and interventions among males with DMD in the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) from 2000 to 2011.

Sibling concordance for clinical features of Duchenne and Becker muscular dystrophies.

Introduction: The correlation of markers of disease severity among brothers with Duchenne or Becker muscular dystrophy has implications for clinical guidance and clinical trials.

Methods: Sibling pairs with Duchenne or Becker muscular dystrophy (n = 60) were compared for ages when they reached clinical milestones of disease progression, including ceased ambulation, scoliosis of ≥ 20°, and development of cardiomyopathy.

Results: The median age at which younger brothers reached each milestone, compared with their older brothers ranged from 25 months younger for development of cardiomyopathy to 2 months older for ceased ambulation.

Oral corticosteroids and onset of cardiomyopathy in Duchenne muscular dystrophy.

Objective: To estimate the age when cardiomyopathy develops in boys with Duchenne muscular dystrophy (DMD) and to analyze the effect of corticosteroid treatment on the age of cardiomyopathy onset.

Study Design: We identified a population-based sample of 462 boys with DMD, born between 1982 and 2005, in 5 surveillance sites in the US. Echocardiographic and corticosteroid treatment data were collected.