Inclusion Body Myositis Associated With ‘Unique’ Comorbidities

The full spectrum of comorbidities of inclusion body myositis (IBM) have only come into focus in the recent past, explains Bhaskar Roy, MD, MBBS, MHS. “Dysphagia in IBM can be disabling, and potentially fatal, but it has been historically ignored,” he says. “The comorbidities associated with IBM in the inpatient setting provide a bigger picture of IBM-related complications and show how IBM differs from other inflammatory myopathies. Additionally, it illustrates the burden of dysphagia in patients with IBM who required more percutaneous endoscopic gastrostomy (PEG) tube placements and experienced more episodes of aspiration pneumonia.”

IBM has a different clinical presentation than other inflammatory myopathies, according to Dr. Roy, and patients with IBM do not respond to immunotherapies. “Apart from the disabling asymmetric muscle weakness, IBM can lead to dysphagia and increased falls. Furthermore, some comorbidities of IBM are not yet fully recognized. A knowledge gap exists about the impact of different comorbidities in IBM.

Dysphagia Poses a Huge Burden in IBM

For a study published in Clinical and Experimental Rheumatology, Dr. Roy and colleagues examined the National Inpatient Sample (NIS) database and assessed the potential complications of IBM-related comorbidities. “We also compared them against other inflammatory myopathies,” he says. “We used ICD code-based search strategies to identify this cohort and excluded patients with multiple neuromuscular disorders or multiple types of inflammatory myopathies.”

The study team concurs that dysphagia poses a big burden in IBM. “The risk for aspiration is three times higher in patients with IBM,” Dr. Roy notes. “Physicians need to be careful about the potential development of aspiration pneumonia in patients with IBM, as they are more prone to require PEG tube placement to maintain safe nutrition. The risk for falls for patients with IBM in an inpatient setting is high, and care providers need to be mindful.”

A proper swallow assessment and appropriate dietary changes can be helpful to prevent dysphagia related complications, he explains, adding that PEG tube placement may be a safer option for nutrition in an appropriate setting. “Physicians should be aware about the risk for aspiration pneumonia, and early signs of respiratory distress and/or respiratory symptoms should be monitored carefully,” he says. “It remains unclear why patients with IBM experienced increased rates of sepsis, but care providers should look for early signs of the condition.

Cardiovascular System Is Not Primarily Affected in IBM

The study team observed that some of these complications were specific to IBM and not influenced by age- or gender-related variations. Furthermore, the study confirms that the cardiovascular system is not primarily affected in IBM (Table).

“Our research highlights that patients with IBM have unique comorbidities compared with other inflammatory myopathies,” Dr. Roy points out. “It also reflects on the poor QOL in patients with IBM. This study raises awareness about the potential comorbidities in IBM and complications related to them. Early recognition can avert some of the potential complications and may improve inpatient care.”

Dr. Roy and colleagues would like to see dedicated studies on the path mechanistic aspect of dysphagia in IBM and how to improve it. “We have only recently recognized the burden of dysphagia in IBM,” he says. “Early intervention may improve QOL significantly. Similarly, there is a need to better understand the gait dysfunction in IBM. Only limited studies have focused on gait dysfunction, and to date, there is no dedicated assisted device that is specific for patients with IBM.”

Finally, “despite all our efforts in the last two decades, there is no approved therapy for IBM,” Dr. Roy says. “We definitely need to better understand the disease pathophysiology and more clinical trials focused on IBM.”