Self-reported physical capacity and activity in patients with systemic sclerosis and matched controls

The aim was to investigate differences in self-reported physical capacity and activity between systemic sclerosis (SSc) patients and population-based controls, as well as between patients with normal-mild, or moderate-severe, lung disease and their respective controls.

The study included 106 patients fulfilling the American College of Rheumatology SSc criteria and 106 controls, individually matched for age and gender. Patients were subdivided into normal-mild and moderate-severe lung disease based on results from pulmonary function tests and SSc severity scale. Participants answered questions regarding physical capacity and activity, exercise, and time spent sitting.

SSc patients reported overall lower capacity for walking, jogging, and running (p < 0.001), and more limiting factors for physical capacity than controls (p < 0.001). Both patients with normal-mild and moderate-severe lung disease also reported lower overall physical capacity than their respective controls (p = 0.001, p < 0.001). Normal-mild lung disease patients reported pain more often than their controls (p < 0.05), whereas moderate-severe lung disease patients reported cardiopulmonary disease (p < 0.001) and reduced muscle strength (p = 0.03) as limiting factors for physical capacity more often than their controls. More patients than controls had 'never exercised' for at least 30 min per occasion within the past year (28% vs 15%, p = 0.03); however, there were no differences overall between patients and controls in frequency of exercise, physical activity, or time spent sitting.

Although SSc patients reported lower physical capacity and more limiting factors for physical capacity than controls, there were no differences in reported physical activity and time spent sitting. Further development of physical activity programmes for SSc patients, especially for patients who never exercise or have physical impairments, is needed.