Cardiopulmonary Exercise Testing In Children With Primary Ciliary Dyskinesia And Healthy Controls

PURPOSE: Cardiopulmonary exercise testing (CPET) offers a comprehensive evaluation of the integrative physiological responses during exercise. Children with primary ciliary dyskinesia (PCD) may exhibit distinctions in responses to CPET compared to healthy children. We aimed to compare the CPET responses between children with PCD and healthy controls. METHODS: Twenty-three children with PCD (mean age: 13.2 ± 3.0 years, 10F) and 23 healthy controls (mean age: 12.4 ± 2.1 years, 9F) were included. A pulmonary function test was performed. All participants performed CPET using the Bruce protocol. Heart rate (HR) and oxygen saturation (SpO2) were measured. Dyspnea and fatigue perceptions were recorded using the modified Borg Scale before and after the tests. The comparisons were performed using the Student t-test and Mann-Whitney U test depending on the normality. RESULTS: Pulmonary function testing parameters were significantly lower in children with PCD than controls (p < 0.05). The children with PCD had significantly lower peak oxygen uptake (VO2peak), HR response, the lowest SpO2, and higher minute ventilation/carbon dioxide production (VE/VCO2) at anaerobic threshold (AT) observed during CPET compared to controls (p = 0.041, p = 0.003, p < 0.001, and p = 0.047, respectively). Although not significant, children with PCD tended to have higher VE/VCO2 slope (p = 0.065) with a lower VO2/HR@max (p = 0.085). One-minute HR recovery (HRR1) was significantly lower in children with PCD than controls (p = 0.006). There were no significant differences between groups regarding change in post-and pre-CPET dyspnea and fatigue perception (p > 0.05). CONCLUSIONS: Children with PCD exhibit reduced aerobic capacity compared to their age and sex matched controls. Lower HR response and HRR1 with a higher VE/VCO2@AT and the tendency toward higher VE/VCO2 slope and lower VO2/HR@max compared to healthy peers suggest impaired chronotropic response, HR recovery, and decreased ventilatory efficiency in children with PCD. Given cardiovascular and ventilatory responses, as well as lower exercise capacity and higher desaturation during exercise in children with PCD compared to controls, it is imperative to aim to enhance the aerobic capacity and direct research efforts toward relevant interventions in this population.