Maximal exercise capacity and related factors in patients with breast cancer

Abstract

Aim: Breast cancer is a multisystem disorder that has seen many problems may affect exercise capacity. The purpose was to investigate the relationship between maximal exercise capacity and physical activity, lung function, dyspnea, peripheral and respiratory muscle strength in breast cancer patients. Methods: Twenty-seven female breast cancer survivors (49.3±5.7 years) participated. Lung function test was performed. Inspiratory and expiratory muscle strength (MIP and MEP, respectively) were measured. Exercise capacity was assessed using the incremental shuttle walk test (ISWT), and oxygen comsumption was calculated. During the test, heart rate, dyspnea and fatigue perception (using modified Borg Scale), and oxygen saturation (SpO2) using pulse oximeter were measured. Quadriceps muscle strength was evaluated using a hand-held dynamometer. Physical activity level was measured using the International Physical Activity Questionnaire (IPAQ). Results: Oxygen consumption at ISWT was related to MIP (r=0.448, p=0.019). Exercise dyspnea perception was significantly associated with FVC (r=-0.467, p=0.029), MEP (r=-0.385, p=0.047), quadriceps muscle strength (r=-0.426, p=0.027), and IPAQ moderate physical activity score (r=-0.384, p=0.048). Exercise oxygen saturation was related with FVC (r=-0.488, p=0.021). Conclusion: Maximal exercise capacity was related with inspiratory muscle strength. Higher exertional dyspnea correlated with peripheral and respiratory muscle weakness, lung function deterioration, and reduced physical activity level. Exercise training should include not only aerobic exercise training, but also peripheral and respiratory muscle strength training, and physical activity counseling.