UK Panel Expands Care Guidelines for Adults With DMD
The U.K. Adult North Star Network (ANSN) has developed a set of guidelines for best care management of adults with Duchenne muscular dystrophy (DMD) based on consensus among experts in the field.
The guidelines were outlined in a report, “Adult North Star Network (ANSN): Consensus Guideline For The Standard Of Care Of Adults With Duchenne Muscular Dystrophy,” published in the Journal of Neuromuscular Diseases.
Due to treatment advancements in the past decade, including improved standard of care across treatment centers and access to clinical trials that have led to the approval of disease-modifying therapies, people with DMD are living longer and well into their fourth decade.
However, with improved life expectancy, older patients are experiencing additional health complications not yet fully addressed in international standards of care and with limited high-quality published evidence of their management.
“Most adults with DMD are medically frail and thus highly vulnerable,” Ros Quinlivan, MD, the report’s lead author, from the MRC Centre for Neuromuscular Disease, University College London’s Institute of Neurology, National Hospital for Neurology and Neurosurgery, in London, said in a press release.
“As their condition progresses, in addition to severe muscle wasting and weakness, they may experience increasingly complex health issues including [heart] failure, weight loss, metabolic decompensation, pain, bladder symptoms, [kidney] dysfunction, and bowel dysmotility that do not generally occur in childhood,” she added.
“For adult patients the emphasis of care shifts from a preventive approach to a treatment approach, which is not fully addressed in previously published guidelines, and healthcare providers are less experienced in managing these patients,” Quinlivan said.
To address this, the ANSN set out to develop consensus-based, standard-of-care recommendations focused on the needs of adults with more advanced disease and who can no longer walk.
ANSN, established in 2015 to improve care of adults with DMD living in the U.K., comprises 28 centers caring for at least 700 DMD adult patients.
The goal of these new recommendations — whose development was funded by Muscular Dystrophy UK — was not to replace current international standards of care but to expand on them, serving as “a framework to improve clinical services and multi-disciplinary care for adults living with Duchenne Muscular Dystrophy,” the researchers wrote.
Expert consensus was achieved through a series of multidisciplinary workshops that included clinicians and health professionals from a wide range of clinical areas and with experience in caring for adults with DMD, as well as patients followed at ANSN’s centers and representatives from patient advocacy groups. These workshops were held over three years.
Relevant clinical areas included neurology, cardiology, respiratory medicine, gastroenterology, endocrinology, palliative care, rehabilitation, renal medicine, anesthesiology, and psychology.
“Detailed reports of evidence reviewed and the consensus building process were produced following each workshop and condensed into this final document which was approved by all members of the Adult North Star Network including service users,” the researchers wrote.
The key recommendations are briefly described below.
Corticosteroids, an anti-inflammatory and immunosuppressive standard treatment for DMD, are associated with several side effects, such as high blood pressure, infections, obesity, gastrointestinal problems, and bone fragility.
As such, adult patients on corticosteroids should be closely monitored to mitigate such complications.
While there is little evidence that starting corticosteroids in adult patients is beneficial, discontinuation should be considered only when side effects outweigh benefits or if the patient chooses to stop them.
In addition, evidence suggests that the need to initiate non-invasive ventilation is delayed in patients receiving corticosteroids.
Given that respiratory failure is “inevitable” in adults with DMD, their lung function should be monitored regularly by experienced clinicians. Adult patients should also be screened for nocturnal hypoventilation (shortness of oxygen and carbon dioxide buildup) due to weakness in the muscles involved in breathing.
Patients on corticosteroids are also at risk of obstructive sleep apnea, a condition characterized by recurrent episodes of complete or partial airway obstruction during sleep.
The expert panel also emphasized that the respiratory multidisciplinary team “should support patients receiving ventilation offering a holistic and comprehensive service.”
All people with DMD eventually develop cardiomyopathy, a life-threatening condition that makes it harder for the heart to pump blood to the rest of the body. As such, heart function should be monitored at least once a year, and all patients should be receiving blood-pressure-reducing therapies, such as ACE inhibitors, beta blockers, and eplerenone.
While most pediatric patients are likely to be on these treatments before transitioning to adult services, “doses will need to be optimised in line with patient size, weight and age changes over time thereafter,” the researchers wrote.
Adults with DMD may develop kidney problems, most likely as a result of progressive heart disease and its treatment, but there is no specific guidance for managing such complications. The expert panel recommended that kidney function should be monitored annually, as well as the levels of red cells, as low red blood cell counts (anemia) may be a sign of kidney failure.
Gastrointestinal symptoms, such as constipation and abdominal bloating, are common in adults with DMD, and require regular monitoring and management.
In addition, given their risk of either obesity due to corticosteroids or weight loss due to swallowing and chewing difficulties, patients should monitor their weight and health under the supervision a dietitian, and a speech and language specialist.
Metformin, a therapy for type 2 diabetes, may be considered for obese patients with metabolic syndrome — a cluster of conditions that include high blood pressure, high blood sugar, excess fat around the waist, and abnormal cholesterol levels.
Given that reduced muscle strength and corticosteroid treatment increase the risk of bone damage and fragility, all patients should be regularly monitored by a medical team that includes a metabolic bone specialist. They may also need vitamin D supplements to improve bone health.
Depression, anxiety, phobias, obsessive-compulsive disorders, and autism are common among adults with DMD. Patients should have access to psychological support, including medical treatment when needed, to improve their mental health and participation in daily activities, and to reduce their psychological symptoms.
The panel recommended that patients requiring general anesthesia should be managed in centers with expertise in the care of adults with DMD, and that their lung and heart function should be comprehensively assessed before they go under anesthesia.
Adult patients approaching end of life should have access to a palliative care consultant to help them manage their symptoms and to discuss an advance care plan that addresses their wishes “regarding ceiling of care and priorities,” the experts wrote.
Overall, adults with DMD “have complex health needs and should be seen in centres with experience and expertise in the management of DMD,” the researchers wrote.
“We hope that these recommendations will support physicians caring for adults with DMD, and thus provide better equity of care for patients and improve outcomes,” Quinlivan said.
“This Guideline also highlights gaps in the literature where further research is required, for example, in managing [gastrointestinal and kidney] complications of the disease,” she said.