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Purpose: Prader–Willi syndrome (PWS) is a genetic neurobehavioral disorder presenting hypothalamic dysfunction and adiposity. At rest, PWS exhibits hypoventilation with hypercapnia. We characterized ventilatory responses in children with PWS during exercise. Methods: Participants were children aged 7–12 years with PWS (n = 8) and without PWS with normal weight (NW; n = 9, body mass index ≤ 85th percentile) or obesity (n = 9, body mass index ≥ 95th percentile). Participants completed three 5-minute ambulatory bouts at 3.2, 4.0, and 4.8 km/h. Oxygen uptake, carbon dioxide output, ventilation, breathing frequency, and tidal volume were recorded. Results: PWS had slightly higher oxygen uptake (L/min) at 3.2 km/h [0.65 (0.46–1.01) vs 0.49 (0.34–0.83)] and at 4.8 km/h [0.89 (0.62–1.20) vs 0.63 (0.45–0.97)] than NW. PWS had higher ventilation (L/min) at 3.2 km/h [16.2 (13.0–26.5) vs 11.5 (8.4–17.5)], at 4.0 km/h [16.4 (13.9–27.9) vs 12.7 (10.3–19.5)], and at 4.8 km/h [19.7 (17.4–31.8) vs 15.2 (9.5–21.6)] than NW. PWS had greater breathing frequency (breaths/min) at 3.2 km/h [38 (29–53) vs 29 (22–35)], at 4.0 km/h [39 (29–58) vs 29 (23–39)], and at 4.8 km/h [39 (33–58) vs 32 (23–42)], but similar tidal volume and ventilation/carbon dioxide output to NW. Conclusion: PWS did not show impaired ventilatory responses to exercise. Hyperventilation in PWS may relate to excessive neural stimulation and metabolic cost.
Hyde, Chavoya, and Rubin are with the Dept. of Kinesiology, California State University, Fullerton, Fullerton, CA. McMurray is with the Dept. of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC.