Impaired exercise performance in systemic sclerosis and its clinical correlations

OBJECTIVES: To investigate the prevalence of impaired exercise performance as assessed by a standardized cardiopulmonary exercise test (CPET) in systemic sclerosis (SSc) and to identify the associated disease features. METHODS: Forty-six SSc patients were enrolled and evaluated for clinical and serological SSc subset, extent of skin and internal organ involvement, and disease activity and severity. Exercise performance was subsequently evaluated in these patients and in 23 healthy individuals matched for sex and age, using a standardized CPET. RESULTS: Exercise performance, measured by maximum oxygen uptake (VO2 max < 80% of predicted value), was found to be impaired in 43/46 patients. Stepwise regression analysis showed that VO2 max adjusted for body weight VO2 max/kg) was independently correlated with the severity of heart (p = 0.001) and lung (p = 0.013) involvement, left ventricular diastolic dysfunction (p = 0.009), and the Health Assessment Questionnaire Disability Index (HAQ-DI) score (p = 0.016). CONCLUSIONS: This study demonstrates that physical disability contributes significantly to the development of impaired exercise performance in SSc patients. Cardiopulmonary exercise testing may be included among the battery of tests used to determine the severity of SSc.