Table 1 Summary matrix of original published studies investigating inspiratory muscle training in individuals with cystic fibrosis
From: Inspiration for the Future: The Role of Inspiratory Muscle Training in Cystic Fibrosis
Study | Patient demographics* | Protocol | Comparison | Primary outcomes |
|---|---|---|---|---|
Asher, 1982 | Age: 16.0 ± 4.6 %BMI: 82.6 ± 9.9 %FEV1: 35.0 ± 12.3 MIP: 74 ± 18 | Mode: Flow-based Intensity: Rmax Frequency: BID Duration: 15 min/day; 4 weeks | Subjects served as their own controls with a 4-week control period followed by a 4-week intervention period. | Increase in IMS (9.5%; p < 0.025) and IME; no effect on exercise performance. |
Sawyer, 1993 | Age: 11.5 ± 2.5 BMI**: 18.4 NIHS: 87.7 MIP: 107 ± 29 | Mode: Threshold Intensity: 50–60% MIP Frequency: 7 days/week Duration: 30 min/day; 10 weeks | Compared to a sham group who performed trained at ≤ 10% MIP. | Increase in MIP (13%; p < 0.01), VC (17%), TLC (13%; p < 0.01), and maximal exercise capacity (9.8%; p < 0.03) with observed increase in sputum production. |
De Jong, 2001 | Age: 17 ± 5.2 BMI**: 17.9 %FEV1: 70 ± 25 %MIP: 105 ± 23 | Mode: Threshold Intensity: 40% MIP Frequency: 5 days/week Duration: 20 min; 6 weeks | Compared to a sham group who performed trained at 10% MIP. | Increase in IME (35%; p = 0.003) with no significant effect on exercise, dyspnea, or fatigue. |
Enright, 2004 | Age: 24.8 ± 5.5 BMI**: 22.3 %FEV1: 64.2 ± 29.7 MIP: 134 ± 26 | Mode: Computer interface Intensity: 80% SMIP Frequency: 3 days/week Duration: 6 sets, 6 reps; 8 weeks | Compared to a sham group at 20% SMIP and a control group. | Increased SMIP and MIP with 80% and 20% training groups with no between group differences. Increased diaphragmatic thickness (20%), VC (24%), TLC (12%), and PWC (51%); decreased anxiety and depression in the 80% group only. |
Santana-Sosa, 2014 | Age: 11 ± 1 BMI: 16.6 ± 0.7 FEV1: 1.65 ± 0.19 MIP: 68.3 ± 6.3 | Mode: Threshold combined with exercise program. Intensity: 40–50% MIP Frequency: BID Duration: ~ 5 min of 30 inspirations; 8 weeks | Compared to a sham group who was trained at 10% MIP. | Increased MIP (58%), VO2peak (22%), and muscular strength in the intervention group. |
Bieli, 2017 | Sequence IC*** Age: 15.4 (12.0:16.6) BMI**: 17.8 zFEV1: − 0.9 (− 2.8:0.5) MIP: Not reported Sequence CI*** Age: 13.2 (10.9:17.8) BMI**: 19.7 zFEV1: − 2.1 (− 3.4 : - 0.5) MIP: Not reported | Mode: Eucapnic hyperventilation Intensity: Not reported Frequency: BID, 5 days/week Duration: 10 min; 8 weeks | Randomized crossover comparison. | Increased RME (105%) but not exercise endurance, lung function, or quality of life. |