Conflict of interest: Nothing to report
Exercise tolerance, lung function abnormalities, anemia, and cardiothoracic ratio in sickle cell patients
Article first published online: 16 MAY 2014
© 2014 Wiley Periodicals, Inc.
American Journal of Hematology
Volume 89, Issue 8, pages 819–824, August 2014
How to Cite
van Beers, E. J., van der Plas, M. N., Nur, E., Bogaard, H.-J., van Steenwijk, R. P., Biemond, B. J. and Bresser, P. (2014), Exercise tolerance, lung function abnormalities, anemia, and cardiothoracic ratio in sickle cell patients. Am. J. Hematol., 89: 819–824. doi: 10.1002/ajh.23752
- Issue published online: 14 JUL 2014
- Article first published online: 16 MAY 2014
- Accepted manuscript online: 3 MAY 2014 03:32AM EST
- Manuscript Accepted: 28 APR 2014
- Manuscript Revised: 21 APR 2014
- Manuscript Received: 12 MAR 2014
Many patients with sickle cell disease (SCD) have a reduced exercise capacity and abnormal lung function. Cardiopulmonary exercise testing (CPET) can identify causes of exercise limitation. Forty-four consecutive SCD patients (27 HbSS, 11 HbSC, and 6 HbS-beta thalassemia) with a median age (interquartile range) of 26 (21–41) years underwent pulmonary function tests, CPET, chest x-ray, and echocardiography to further characterize exercise limitation in SCD. Peak oxygen uptake (V′O2-peak), expressing maximum exercise capacity, was decreased in 83% of the studied patients. V′O2-peak correlated with hemoglobin levels (R = 0.440, P = 0.005), forced vital capacity (FVC) (R = 0.717, P < 0.0001). Cardiothoracic ratio on chest x-ray inversely correlated with FVC (R = −0.637, P < 0.001). According to criteria for exercise limitation, the patients were limited in exercise capacity due to anemia (n = 17), cardiovascular dysfunction (n = 2), musculoskeletal function (n = 10), pulmonary ventilatory abnormalities (n = 1), pulmonary vascular exercise limitation (n = 1), and poor effort (n = 3). In the present study we demonstrate that anemia is the most important determinant of reduced exercise tolerance observed in SCD patients without signs of pulmonary hypertension. We found a strong correlation between various parameters of lung volume and cardiothoracic ratio and we hypothesize that cardiomegaly and relative small chest size may be important causes of the impairment in pulmonary function, that is, reduced long volumes and diffusion capacity, in SCD. Taking into account anthropomorphic differences between SCD patients and controls could help to interpret lung function studies in SCD better. Am. J. Hematol. 89:819–824, 2014. © 2014 Wiley Periodicals, Inc.