Physical capacity in performing daily activities is reduced in scleroderma patients with early lung involvement

Abstract

BACKGROUND: Patients with systemic sclerosis (SSc) often complain reduced capacity at submaximal exercise; conversely physical capacity in performing daily duties has never been measured in SSc. OBJECTIVES: To evaluate this performance and its correlates, in patients with SSc compared to healthy controls, in a free-living setting. METHODS: Twenty-seven outpatients with stable SSc and 11 controls were recruited. Physical activity was assessed by portable multiple sensor device (SenseWear Armband) worn for at least six days. Physical activity duration (PAD; in minutes) for non-sedentary activities and physical activity level (PAL= total daily energy/resting energy expenditure) per day were calculated. Nutritional status was estimated by bioelectrical impedance analysis, and pulmonary arterial hyperthension excluded by echocardiography. RESULTS: Daily physical activities (243+/-145 minutes per day versus 397+/-142 min, respectively; p=0.005) and PAL were significantly reduced in SSc compared to controls (1.5+/-0.4 vs 2+/-0.7, respectively; p=0.019). 74% of SSc patients showed PAL <1.70, whereas only 27% of controls were below this threshold for sedentary life style. Both PAD and PAL positively correlated with DLco. Patients and controls did not differ for spirometric parameters, BMI, phase angle at bioelectrical impedance analysis, fat mass or fat-free mass indexes. In SSc, exercise capacity during daily activity was reduced compared to controls, and was associated with early evidence of functional decay (decreasing DLco) but not with malnutrition (undernutrition). CONCLUSIONS: A reduction of daily physical activity is already present even in early stages of lung involvement in SSc, characterized by unaltered spirometry and well preserved nutritional status.