Reduced Muscle Strength Leads to Poor Quality of Life in ANCA Vasculitis Patients, Study Says

Long-term disease and treatment-related damage reduce the muscle strength and physical capacity of people with ANCA-associated vasculitis. The resulting reduction in physical activity diminishes the quality of life, a study suggests.

The study, “Leg muscle strength is reduced and is associated with physical quality of life in Antineutrophil cytoplasmic antibody-associated vasculitis,” was published in PLOS ONE.

Life expectancy of patients with ANCA vasculitis has significantly increased thanks to treatments that combine anti-inflammatories and immunosuppressants.

Currently, most cases achieve remission. However, long-term disease and use of medication can lead to secondary effects that affect patients’ physical and mental health.

People with ANCA vasculitis have decreased physical quality of life when compared to the general population. Therefore, it is important to identify modifiable factors associated with disease management.

One of these is the use of glucocorticoids such as prednisolone, which has been associated with damage to the muscles of the limbs and reduced physical activity. In turn, this seems to affect quality of life.

This study set out to see whether there was an association between physical quality of life, muscle strength, and physical activity in ANCA vasculitis and to assess whether the loss of muscle strength was related to disease duration and exposure to treatment, especially glucocorticoids.

Researchers evaluated 48 adults diagnosed with microscopic polyangiitis (MPA) or granulomatosis with polyangiitis (GPA), the two most common subsets of ANCA vasculitis.

The time from diagnosis or most recent relapse was less than three years, and induction therapy — treatment to cause remission — had to be a combination of prednisolone and an immunosuppressant. The participants had no other conditions that could alter muscle strength and physical activity.

Measurements of muscle strength were taken and physical activity and quality of life were assessed via surveys filled out by the participants.

Most patients had less strength in the knee (76%) and elbow (67%) than expected based on literature parameters. The physical and, to a lesser extent, mental quality of life were also below healthy parameters.

Reduced muscle strength in the knee, younger age at diagnosis, and more relapses were associated with lower physical quality of life, while reduced physical activity, higher prednisolone doses, and disease involvement were associated with lower mental quality of life.

Long-term use of prednisolone had a negative impact on physical capacity and physical activity, which, in turn, had a negative effect on the quality of life.

“Relapsing patients with longer disease duration more frequently had a muscle strength below [normal] values. This suggests that accumulating damage from relapses of [ANCA vasculitis] and treatment of these relapses results in a reduction of muscle strength over time,” researchers said.

They concluded that “based on these results, interventions focusing on improving muscle strength and exercise capacity might improve both physical and mental [quality of life] in [ANCA vasculitis] patients.”