Abstract
Rationale:
Exercise training of at least 10 weeks duration induces significant changes in myofiber size, capillarization and distribution in patients with emphysema. Up to date it is unknown which changes in muscle structure can be achieved by a German inpatient PR with a standard duration of 3 weeks.
Methods:
Ten patients with emphysema (age: 57±5y; BMI: 24±3kg/m2; FEV1: 31±9%pred.) were included in this prospective trial. All patients performed an incremental cycle test to determine the peak work rate (PWR). The PR included daily supervised exercise training sessions (strength- and endurance training). Pre and post PR, biopsies from vastus lasteralis muscle were taken.
Results:
PWR improved significantly during PR (+17Watt [95% CI, 6.3 to 27.7] p<0.01). We observed a significant increase in the capillary to fibre ratio in fibre types I and IIa respectively (+0.5% [95% CI, 0.1 to 1.0] p=0.03; +1.0% [95% CI, 0.6 to 1.4] p<0.01) in skeletal muscle. We found a significant negative correlation between FEV1% pred. and the change in capillary to fibre I ratio (r=-0.633, p<0.05).
A non-significant but notable increase in the quantity of fibre type I (+6.5%), IIa (+2.2%) and IIx (+2.6%) was detected. Hybrid fibres decreased during PR (type I/IIa: -1.3% [95% CI, -2.21 to -0.39] p<0.01; type IIa/IIx: -5.2%, p=0.09).
Conclusions:
These preliminary data show that an inpatient 3-week PR is able to exert relevant adaptations in peripheral muscle of COPD patients. This includes an increase in capillarization and an augmented type I myofiber distribution. To confirm these first results, further patients will be investigated.
- © 2012 ERS