Lack of Diagnostic Information About Sarcopenia in Rheumatoid Arthritis

New research is needed to determine proper diagnostic measurements for sarcopenia.

Sarcopenia is the loss of muscle mass due to the aging process, and the absence of diagnostic definitions for this condition may present treatment barriers in individuals with rheumatic diseases.

The Update: Sarcopenia in Rheumatic Disease session at the American College of Rheumatology and Association of Rheumatology Health Professionals annual meeting provided attendees with updated research, diagnosis, and treatment information about sarcopenia.

The session focused on the creation of universal criteria that could be used to help identify the condition that can impact patients’ quality of life.

“Everyone, even world-class athletes, experiences loss of muscle mass and strength starting in the fourth decade of life,” said Robert R. McLean, DSc, MPH, Assistant Professor of Medicine at Harvard Medical School and the Hebrew SeniorLife Institute for Aging Research in Boston. “But this process is accelerated in many rheumatic diseases primarily due to elevated inflammatory status, which is catabolic to muscle.”

The muscle loss could also stem from a reduction in physical activity as a result of pain and comorbidities. A change in diet could also affect muscle loss.

The largest challenge facing the management of the condition is diagnosis, according to the session.

“Although many definitions of sarcopenia have been proposed and used in research studies, there are currently no consensus criteria to determine low muscle mass or weakness,” Dr McLean said.

Dual-energy x-ray absorptiometry, which is used to determine bone density, could potentially be used to diagnose sarcopenia since it can also determine muscle mass. Other approaches to measure muscle strength are commonly used, but clinically meaningful measurements with these tools have not been determined, according to the session.

After sarcopenia is diagnosed, there are few treatment options that have found successful in preventing additional muscle loss. Resistance exercise is the only approach that has been shown to improve muscle mass and strength in patients.

“Right now, I think the best we can do is to ensure that patients are participating in these activities and maintaining a healthy diet that includes plenty of protein,” Dr McLean said.

The session also discussed current research about sarcopenia, especially research efforts being made to determine a diagnosis. This research is being conducted by the National Institute on Aging in collaboration with other organization, and aims to have a consensus about diagnostic criteria and how to implement them.

“While these efforts are borne out of the field of aging research, this groundbreaking work will promote similar advances in other patient groups, including the rheumatic diseases,” Dr McLean said.

The proposed criteria to determine a diagnosis includes grip strength cutoff, appendicular lean mass, and walking speed, but they need to be validated in studies, according to the session.

“I’m hoping that attendees will understand that changes in muscle health in rheumatic disease have a profound impact on clinical outcomes, particularly disability,” Dr McLean concluded.