Purpose: Declining inspiratory muscle function and structure and systemic low-level inflammation and oxidative stress may contribute to morbidity and mortality during normal ageing. Therefore, we examined the effects of inspiratory muscle training (IMT) in older adults on inspiratory muscle function and structure and systemic inflammation and oxidative stress, and re-examined the reported positive effects of IMT on respiratory muscle strength, inspiratory muscle endurance, spirometry, exercise performance, physical activity levels (PAL) and quality of life (QoL).
Methods: Thirty-four healthy older adults (68 +/- 3 years) with normal spirometry, respiratory muscle strength and physical fitness were divided equally into a pressure-threshold IMT or sham-hypoxic placebo group. Before and after an 8 week intervention, measurements were taken for dynamic inspiratory muscle function and inspiratory muscle endurance using a weighted plunger pressure-threshold loading device, diaphragm thickness using B-mode ultrasonography, plasma cytokine concentrations using immunoassays, DNA damage levels in peripheral blood mononuclear cells (PBMC) using Comet Assays, spirometry, maximal mouth pressures, exercise performance using a six minute walk test, PAL using a questionnaire and accelerometry, and QoL using a questionnaire.
Results: Compared to placebo, IMT increased maximal inspiratory pressure (+34 +/- 43%, P = 0.008), diaphragm thickness at residual volume (+38 +/- 39%, P = 0.03), and peak inspiratory flow (+35 +/- 42%, P = 0.049), but did not change other spirometry measures, plasma cytokine concentrations, DNA damage levels in PBMC, dynamic inspiratory muscle function, inspiratory muscle endurance, exercise performance, PAL nor QoL.
Conclusion: These novel data indicate that in healthy older adults IMT elicits some positive changes in inspiratory muscle function and structure, but does not attenuate systemic inflammation and oxidative stress, nor improve exercise performance, PAL or QoL.
(C) 2014 American College of Sports Medicine