Functional capacity and peripheral muscle strength are reduced in asthmatic children and teenager

Introduction: A shuttle walk test (SWT) has been widely used for evaluating functional capacity and response to intervention in people with chronic lung diseases, but has never been used in pediatric asthmatic. Another possible systemic repercussion in this population is impaired skeletal muscle function, but studies investigating peripheral muscle strength (PMS) in these patients are scarce. Aim: To compare PMS and performance on a SWT between asthmatic children and teenagers and healthy volunteers. Method: 15 asthmatic participants (AG) (10years[8–11]) and 10 control participants (CG) (10years[12-15]) underwent spirometry, maximal isometric voluntary contraction for measuring quadriceps femoris (QF) and biceps brachii (BB) strength, and shuttle walk tests (SWT). Heart rate (HR) was continuously measured during the tests. Dyspnea and fatigue were recorded at the beginning and at the end of SWT. Results: Despite there being no difference in lung function between the AG (FEV 1 104%[94–116], FVC 101%[91–109]) and CG (FEV 1 104%[83–114], FVC 98%[80-105]), the AG walked shorter distances on the SWT (670m [544–746m]) compared to the CG (889m [593–1064m]) (p = 0.04).HR was similar between the AG and CG, as were dyspnea and fatigue. Compared to the CG, the AG showed reduced BB and QF strength (BB: 8.1kg[6.6–10.8kg] vs. 5.5kg[5.1-6.5kg], p = 0.02 and QF: 16.3kg[9.4–20.1kg] vs. 9.3kg[7.3–10.6kg], p = 0.01). Conclusion: Functional capacity is reduced in asthmatic children and adolescents. This is the first study to show impaired muscle function in this population and emphasizes the importance of including strength training as part of an exercise program. FAPESP 2014-12040-0; 2014/20857-6.