Purpose
To evaluate the aerobic capacity by cardiopulmonary exercise test (CPET) in children and adolescents with sickle cell disease in comparison with healthy matched controls and to determine the factors associated with impaired maximum oxygen uptake (VO2max) in this population.
Methods and results
A total of 72 children (24 with sickle cell disease and 48 healthy controls), aged 6 to 17 years old underwent a complete CPET and were enrolled in a cross-sectional controlled study. Children with sickle cell disease had a poor aerobic capacity, with median VO2max Z-score values significantly lower than matched controls (-3.55[-4.68; -2.02] vs. 0.25[-0.22; 0.66], P < 0.01, respectively), and a high proportion of 92% children affected by an impaired aerobic capacity (VO2max Z-score<-1.64). The ventilatory anaerobic threshold was impaired in 71% of children with sickle cell disease. The VO2max decrease was associated with the level of anemia, the existence of a homozygote HbS/S mutation, restrictive lung disease (low forced vital capacity associated to low total lung capacity) and health-related quality of life. In multivariate analysis, VO2max Z-score was associated with hemoglobin level (ß=0.37; 95%CI=[0.01; 0.72]; P = 0.04).
Conclusion
Aerobic capacity is poor in children with sickle cell disease. VO2max decrease is associated with the level of anemia, the existence of a homozygote HbS/S mutation, lung function, and health-related quality of life. These results represent a signal in favor of early initiation of cardiac rehabilitation in patients with sickle cell disease.
Clinicaltrials: NCT05995743