Respiratory muscle strength, endurance and oxygen consumption in patients with stable asthma

Abstract

Introduction: Bronchial obstruction(BO) causes expiratory air flow limitation, reduction in maximal exercise capacity and BO associated hyperinflation causes reduction in respiratory muscles’ strength and endurance. However, no study investigated asthmatic patients’ respiratory muscle endurance and there is limited information about respiratory muscle strength and maximal exercise capacity in patients with asthma. We aimed to investigating maximal exercise capacity, pulmonary functions and respiratory muscle strength and endurance in patient with asthma. Methods: Forty-one stable asthmatic patient (49.32±10.95years, FEV1(%):77.51±19.4, 12M/29F, GINA Class I to III) and 41 healthy controls (47.17±9.82years, FEV1(%):103.34±11.9, 11M/30F) were included. All participants’ pulmonary functions(with pulmonary function test), maximal exercise capacity(with cardiopulmonary exercise test[CPET]) (Oxycon mobile, Germany), respiratory muscle strength(with mouth pressure measurement) (MicroMedical MicroRPM, UK) and respiratory muscle endurance(with incremental threshold loading endurance test)(PowerBreathe®, HaB International Ltd., UK) assessed. Results: Asthmatic patients’ pulmonary functions (p 0.05). Discussion: Pulmonary functions, maximal exercise capacity and respiratory muscle endurance impaired but respiratory muscle strength is preserved in patients with asthma. Pulmonary rehabilitation is essential in order to improve impairments.