Evaluation of lung functions during exercise in patients with sickle cell anemia who applied to the pediatric hematology clinic

Objective: This study aimed to evaluate the physiological and metabolic changes in pulmonary function that occur during exercise in pediatric patients diagnosed with sickle cell anemia (OHA) and to compare these findings with healthy peers to elucidate the disease's impact on exercise physiology. Materials and Methods: The study included 10 male children diagnosed with OHA and 10 healthy male controls matched for age and sex. Each participant underwent comprehensive physiological assessments involving hematological, biochemical, spirometric, and gas exchange parameters both before and after exercise. A maximal exercise test was performed using a cycle ergometer, during which oxygen consumption (VO₂), carbon dioxide production (VCO₂), ventilatory responses (VE, VT, Rf), cardiac parameters (HR), and pulmonary function tests including DLCO were measured. Post-exercise painful crises were also recorded. Statistical analysis was conducted using SPSS 27.0; parametric and non-parametric tests were used for within-group and between-group comparisons. Results: Resting hemoglobin (9.7±1.1 g/dL) and hematocrit levels (28.1±2.9%) were significantly lower in the OHA group compared to controls. Post-exercise lactate levels significantly increased in both groups (p<0.001); however, the increase was significantly lower in the OHA group (p=0.042). Although VO₂ Max appeared higher in the OHA group (8.1±6.6 mL/min/kg), the difference was not statistically significant (p=0.190). A significant negative correlation was found between BMI and VO₂ Max (r=-0.690; p=0.001). No significant differences were observed in DLCO or ventilatory parameters between groups during exercise. VO₂ Max was significantly higher in participants who experienced post-exercise painful crises (p=0.042), whereas DLCO values did not differ by crisis status. Generally, weak and non-significant correlations were found between VO₂ Max and cardiopulmonary parameters. Conclusion: Exercise induces notable metabolic responses in individuals with OHA, and VO₂ Max appears to be significantly influenced by BKİ. The association between VO₂ Max and the development of painful crises suggests that this parameter may have clinical predictive value in OHA populations. Keywords: Sickle cell anemia, exercise testing, VO₂ Max, DLCO, pediatric hematology, cardiorespiratory responses.