Physiological Responses to Maximal Exercise Capacity and Muscle Strength in Survived Hematopoietic Stem Cell Transplantation Recipients

Treatments of hematologic malignancies consist of chemotherapy, radiotherapy, surgery, medical treatment, supportive care and/or hematopoietic stem cell transplantation (HSCT) which is resulted in early or late adverse effects on body systems, tissues and organs. Physical deconditioning is also observed in patients with hematologic malignancies because of reasons such as neurotoxic and pulmonary toxic effects of long term these anticancer treatments, immobilization, recommendation of resting and avoiding intense exercise, nutrition problems, severe anemia and thrombocytopenia etc. For these reasons, normal physical activities may not be kept on by patients which induces decreased physical performance.

The HSCT provides longer survival with standard treatments for patients with hematological malignancies while it increases risk of HSCT-related toxicity, complications and even mortality. Infectious and non-infectious pulmonary complications occur in about 60% of HSCT recipients and intensive-care unit support is also required in one-third of recipients for these reasons. Restrictive lung disease prior to allogeneic HSCT is related to early respiratory failure, non-relapse mortality and respiratory muscle weakness in post transplantation period. Therefore pulmonary restriction is considered as a risk factor for complications or failure of HSCT. Moreover it is known that carbon monoxide diffusing capacity of lungs which is the most common abnormality seen in pulmonary function test, respiratory muscle strength and functional exercise capacity are reduced in the majority of patients before HSCT. In addition to muscle weakness and decreased exercise capacity at prior to HSCT, patients experience more reduction in both inspiratory and expiratory muscles and exercise capacity after HSCT. Unfortunately, exercise capacity and peripheral muscle strength are decreased in HSCT recipients in spite of doing regular and planned exercise during acute process of HSCT. The average reduction in functional exercise capacity of recipients is 48 m. As shown in the literature, limited number of study has used evaluation of maximal exercise capacity with Modified-Incremental Shuttle Walk Test (ISWT) in HSCT patients and recipients. On the other hand, it has been reported that ISWT is a reliable test and has no adverse event or side effects for HSCT recipients in these studies, as well. Despite the fact that there is no negative feedback related to using of this test in recipients, no study comprehensively demonstrated influence of HSCT on maximal exercise capacity.

Impairments in pulmonary functions, respiratory muscle strength and maximal exercise capacity have been demonstrated in limited number of studies. Moreover, there is no study compared pulmonary functions, respiratory muscle strength and maximal exercise capacity between HSCT recipients and healthy individuals. Therefore investigators aimed to compare aforementioned outcomes between recipients and healthy individuals.