Peripheral muscle oxygenation during upper extremity functional exercise and balance in pediatric patients with cystic fibrosis: a cross-sectional study

Exercise intolerance, muscle weakness, mitochondrial involvement, and slow phosphocreatine metabolism are common, but extrapulmonary impairments in pediatric patients with cystic fibrosis (CF) have not been adequately studied yet. This study compared pulmonary function, upper extremity exercise capacity, muscle oxygenation, peripheral muscle strength, and balance in patients with CF and healthy controls. Thirty-one pediatric patients with cystic fibrosis and 30 healthy controls were compared. Pulmonary function was assessed by spirometry; upper extremity functional exercise capacity was evaluated using the 6-minute Pegboard and Ring Test (6PBRT); deltoid muscle oxygenation was measured at rest, during the 6PBRT, and during recovery using near-infrared spectroscopy; shoulder abductor and knee extensor isometric muscle strength were assessed using a hand-held dynamometer; and static and dynamic balance were evaluated using the Biodex Biosway® Portable Balance System and the Y-Balance Test, respectively. Age and gender were similar in groups (p > 0.05). FEV1%, FVC%, PEF%, FEF25 − 75%, and muscle strength statistically significantly (p < 0.05) decreased in patients. Six-minute PBRT score, deltoid muscle oxygen saturation, and hemoglobin level were similar in groups (p > 0.05). The medial-lateral stability index of patients on soft ground with eyes open was statistically significantly higher than healthy controls (p < 0.05). Upper extremity exercise capacity, muscle oxygenation, and most parameters of balance are preserved, and peripheral muscles are weakened in mildly impaired patients with CF. Impaired pulmonary function may impair upper extremity exercise capacity and muscle oxygen metabolism in severe patients with CF, should be investigated.