Muscle oxygen extraction and lung function are related to exercise tolerance after allogeneic hematopoietic stem cell transplantation

Purpose This study aimed to investigate the relationship between exercise intolerance, muscle oxidative metabolism, and cardiopulmonary function following allogeneic hematopoietic stem cell transplantation (allo-HSCT) in a sterile isolation room setting. Methods This was a prospective observational cohort study conducted in a single center. Fourteen patients with hematopoietic malignancies who had undergone allo-HSCT were included in this study from June 2015 to April 2020. Patients received donor HSCT after high dose-chemotherapy and total-body irradiation. Physical activity was limited during treatments. Outcome measures included body anthropometric measurements, exercise tolerance tests using the ramp protocol, pulmonary function tests, and near-infrared spectroscopy (NIRS) measurements. Data of pre- and posttransplant measurements were compared using the paired t test or nonparametric Wilcoxon U test. Associations were assessed using the Pearson or nonparametric Spearman correlations. Results NIRS showed reduced muscle consumption and extraction of oxygen in the posttransplant period compared to the pretransplant period (Delta StO(2 min) pre: -18.6% vs. post: -13.0%, P = 0.04; Delta HHb (max) pre: 4.21 mu mol/l vs. post: 3.31 mu mol/l: P = 0.048). Exercise tolerance had reduced following allo-HSCT (Peak workload pre: 70.3 W vs. post: 58.0 W: P = 0.014). Furthermore, exercise intolerance was associated with pulmonary function, muscle oxygen consumption, and muscle oxygen extraction (all P <0.05). Conclusion This analysis revealed that exercise intolerance following allo-HSCT was associated with pulmonary dysfunction and muscle oxidative dysfunction. These findings could help identify the physical function associated with impaired tissue oxygen transport leading to exercise intolerance following allo-HSCT.

Automated summary

Exercise intolerance following allo-HSCT is associated with pulmonary dysfunction and muscle oxidative dysfunction, potentially due to impaired tissue oxygen transport. These findings could help identify the physical function associated with exercise intolerance in patients post allo-HSCT.