Findings from a study of 516 Italian boys show a significant improvement over the last six decades in survival time in Duchenne muscular dystrophy (DMD). This modified natural history (general disease course) of DMD, the study team reported, stems from the application of a comprehensive therapeutic approach that emphasizes respiratory and cardiac (heart) care.
Specific care components that have contributed to longer life span for those with the disease include noninvasive mechanical ventilation and corticosteroids (steroids such as prednisone, prednisolone and deflazacort) to help breathing function, and drugs called angiotensin-converting enzyme (ACE) inhibitors to improve heart function. (Corticosteroids also are used in DMD to keep muscles stronger longer and to prolong ambulation, or the ability to walk.)
DMD should now be considered not only a pediatric disease, but a disease of adulthood as well, the research team noted, adding that more public health interventions are needed to support individuals with DMD and their families as they transition from childhood into adulthood.
The researchers published their findings Oct. 31, 2012, in Acta Myologica. Read the entire report, free of charge: Improvement of Survival in Duchenne Muscular Dystrophy: Retrospective Analysis of 835 Patients.
Investigators reviewed the medical records of 835 people with DMD who were treated between the years of 1961 and 2006 at the Naples (Italy) Centre of Cardiomyology and Medical Genetics. After eliminating from the study those who had incomplete records, lack of routine follow-up, and those in whom a DMD diagnosis couldn't be confirmed, the remaining 516 were divided by decade of birth into three groups: those born between 1961 and 1970; those born between 1971 and 1980; and those born between 1981 and 1990.
Age and causes of death were analyzed along with details about respiratory and cardiac care. Cardiac and respiratory problems were the main causes of death, with respiratory causes being proportionally higher until the 1980s.
The average age for heart-related deaths was 19.6 years, with an increasing age in the last 15 years. The overall average for deaths attributable to respiratory issues was 17.7 years in people without ventilator support, and 27.9 years in those who used mechanical ventilation.
Improvement in survival rate was observed at two different ages:
The researchers noted that treatment that included noninvasive mechanical ventilation, ACE inhibitors and steroids became standard practice in the care of people with DMD at the Centre in the early 1990s.
Results from a previous study conducted by another group corroborate those from the new study, showing that:
In an effort to better understand how specific interventions such as ACE inhibitors and corticosteroids are connected to health outcomes for people with DMD (or other neuromuscular diseases) in the United States, MDA launched a neuromuscular disease registry through its national network of 200 clinics in October 2012. Through the data it collects, MDA hopes to significantly improve survival and quality of life for those with neuromuscular disease, including DMD, and to help advance clinical trials. In particular, the data are expected to help determine the best ways to provide care. (For example, the data may shed light on the ideal age for a young child with DMD to begin taking corticosteroids.)
MDA's Transitional Services program provides support and resources designed to assist youth with disabilities as they prepare for adulthood and develop life skills necessary for achieving greater independence.
To learn more about interventions that contribute to increased longevity in DMD, see: