Effect of inspiratory muscle training on pulmonary functions, physical capacity, and quality of life: a randomized controlled trial in β-thalassemia children

Background
The respiratory system is one of the most negatively affected systems by β-thalassemia major-associated complications. Compared to normal healthy peers, β-thalassemia major (βTM) children’s values of pulmonary function tests are low, hence pulmonary dysfunctions are present in 80% of βTM children. The causes of pulmonary dysfunctions in βTM children are systemic iron overload resulting from repeated or regular blood transfusion. These children also usually report poor quality of life (QoL), exercise intolerance, and low physical capacity. The respiratory system is one of the most negatively affected systems by β-thalassemia major-associated complications. Compared to normal healthy peers, β-thalassemia major (βTM) children’s values of pulmonary function tests are low, hence pulmonary dysfunctions are present in 80% of βTM children. The causes of pulmonary dysfunctions in βTM children are systemic iron overload resulting from repeated or regular blood transfusion. These children also usually report poor quality of life (QoL), exercise intolerance, and low physical capacity.

Objectives
This study is a randomized controlled study. The aim of this study was to investigate the effect of 12-week inspiratory muscle training (IMT) on βTM children’s pulmonary functions, QoL, and physical capacity (tested via a six-minute walk test (SMWT)).

Material and methods
40 βTM children of both genders were randomly and equally assigned into two groups; IMT group or controlled non-trained βTM children group. Every group contained 20 βTM children. Two supervised IMT sessions were applied daily for six days per week via a threshold Respironics Threshold IMT device. Besides the evaluation of forced expiratory volume at the first second of βTM children’s expiration (FEV1) and SMWT, βTM children’s forced vital capacity (FVC), child and parent reports of Pediatrics’ Quality of Life Inventory, maximal inspiratory pressure (MIP), and FEV1/FVC ratio were assessed.

Results
A significant improvement was reported after executing a comparison between the pre- and post-values of βTM children’s outcomes within the IMT group only.

Conclusions
12-week IMT significantly improves βTM children’s poor QoL, MIP, low physical capacity, and deteriorated pulmonary functions (FVC, FEV1, and FEV1/FVC ratio).