Reduced exercise capacity in systemic sclerosis patients without pulmonary involvement.
OBJECTIVE
To evaluate the exercise capacity of women with systemic sclerosis (SSc) without pulmonary involvement using a cardiopulmonary stress test.


METHODS
Thirteen consecutive female SSc patients [mean age 40.8+/-14 years, mean body mass index (BMI) 25.5+/-3.7 kg/m2] without pulmonary and cardiac involvement and 13 healthy sedentary female controls (mean age 41.6+/-9.1 years, mean BMI 23.7+/-3.8 kg/m2) matched by age and BMI underwent a maximum cardiopulmonary stress test (Bruce protocol). The following parameters were analysed: peak oxygen uptake (VO2peak), anaerobic threshold (AT), respiratory compensation point (RCP) and metabolic equivalent (MET) of the VO2peak. Comparisons between groups were analysed using the Student t-test.


RESULTS
Forced vital capacity (FVC; 92.2+/-14.2% predicted) and carbon monoxide diffusion lung capacity (DL CO; 85.8+/-5.8% predicted) were within the normal range in SSc patients. VO2peak of SSc patients was significantly reduced in comparison to the control group (19.8+/-4.6 vs. 23.7+/-4.5 mL/kg/min, p = 0.04). SSc patients also had a significant reduction in MET at peak exercise (5.6+/-1.3 vs. 6.7+/-1.3 MET, p = 0.04) and a significant shorter time interval between AT and RCP compared to the control group (112.6+/-95.6 vs. 164.0+/-65.3 s, p = 0.03).


CONCLUSIONS
SSc patients without pulmonary impairment have reduced exercise capacity. Abnormal vascular response to exercise may account for this finding, as the vascular system is one of the major target organs in this pathological condition.
de Oliveira
N C
NC
Rheumatology Division, University of Sao Paulo, Brazil. reumato@usp.br
dos Santos Sabbag
L M
LM
Ueno
L M
LM
de Souza
R B C
RB
Borges
C L
CL
de Sá Pinto
A L
AL
Lima
F R
FR
D000328:Adult; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D008168:Lung / Q000378:metabolism / Q000503:physiopathology*; D008171:Lung Diseases; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D011379:Prognosis; D011653:Pulmonary Diffusing Capacity; D012595:Scleroderma, Systemic / Q000378:metabolism / Q000503:physiopathology*; D012720:Severity of Illness Index; D014797:Vital Capacity / Q000502:physiology