Optimizing strategies for assessment and management of limb muscle dysfunction in COPD: Why is it important, and how should it be done?

BACKGROUND: Chronic obstructive pulmonary disease (COPD), currently the third leading cause of mortality worldwide, is a multisystemic disease in which limb muscle dysfunction, is closely linked with poor outcomes such as reduced physical activity, low quality of life, and even premature mortality. However, significant knowledge gaps still exist before the assessment and optimal management of limb muscle dysfunction becomes a reality in clinical practice.

E.g., reliable and valid measurement methods for quadriceps endurance needs to be developed. Furthermore, even though resistance training is highly recommended if the goal is to improve limb muscle dysfunction in COPD, individual variations are large and up to half of all people are considered non-responders after resistance training, despite following current guidelines.

AIM: To fill these knowledge gaps, the aims of the proposed project are to 1) determine the reliability and validity of three novel assessment strategies for quadriceps endurance in COPD, and to determine the effect of a novel non-linear periodized resistance training (NLPRT) regimen that has been created with clinical experts in COPD on 2) muscle strength and endurance, 3) functional performance, quality of life, and dyspnea, 4) feasibility and 5) intramuscular adaptations. We will also, 6) explore the link between dyspnea, functional performance, limb muscle function, and structural and metabolic characteristics of the limb muscles in COPD.

WORKPLAN: For aim 1-2) 90 people with COPD will be recruited across three European and Canadian research centres in a randomized cross-sectional study, while for aim 2-6) an international multicenter randomized controlled trial including will be performed. About the latter, our novel NLPRT regimen will be compared to traditional resistance training performed in accordance with current guidelines in 64 people with COPD. Outcomes (see AIMS above) are evaluated at baseline and after eight weeks of training.

SIGNIFICANCE: The clinical and prognostic relevance of muscle function in COPD warrants continued research into finding clinically relevant methods of investigation as well as effective and feasible training methods. The results from the proposed project will provide new knowledge that will promote the implementation of quadriceps muscle assessment in the clinical context as well as to provide novel evidence on how limb muscle dysfunction should be optimally managed among people with COPD.