Respiratory and Skeletal Muscle

This group, led by Professor Mike Polkey, is concerned with the improvement of exercise performance in chronic obstructive pulmonary disease (COPD). Our fundamental philosophy rests on the ‘spiral of disability'.

Based on this concept we believe that there are 4 key areas where science can enhance the quality of life of patients with COPD. Integral to this work is expertise in the measurement of exercise performance both on exercise tests as well as during daily life. These are:

  1. Reversing quadriceps dysfunction: to address this we have conducted innovative studies to delineate the extent of the problem of skeletal muscle weakness, how best to assess it and its effect on prognosis. We are actively interested in reversing it through pulmonary rehabilitation and eventually through novel pharmacological strategies~to prepare for this we are currently running a biopsy program so that we are well placed to validate targets.  We have also established the largest national network of patients with COPD in whom quadriceps strength and exercise performance have been assessed. Professor Polkey is actively working with the COPD Foundation Biomarker Qualification program to have measures of exercise accepted as a biomarker by the FDA.
  2. Countering anaerobic metabolism: to address this we are currently building on previous work to see whether non-invasive ventilation can enhance exercise performance in COPD and thus be a useful adjunct to pulmonary rehabilitation
  3. Countering hypoxia: Low oxygen levels greatly reduce quality of life for patients with COPD. One cause of a low oxygen level is persistence of a foetal right to left connection, a patent foramen ovale. Current studies are aimed at establishing how common and how important this problem is in COPD.
  4. Reducing ventilatory requirements by improving lung mechanics: We are hopeful that novel mechanical strategies can achieve this aim so this remains an active area for us. We were the first to use one way valves in emphysema and this described our initial experience with trans thoracic pneumonostomy. Most recently we have completed a stratified medicine study funded by the NIHR demonstrating the success of this approach for endobronchial lung volume reduction.

The group is also expert in the assessment of respiratory muscles in diverse clinical situations having described many of the original techniques. We are one of the last centres worldwide who remain able to assess respiratory muscle and pulmonary mechanics using catheters placed in the oesophagus and stomach, and are currently using this approach for a study in Pompe’s disease for which Professor Polkey is chief investigator.

What causes exercise limitation in patients with COPD?

Dr Nick Hopkinson and his team have been addressing the influence of genetic polymorphisms, corticosteroid therapy and the role of acute exacerbations in skeletal muscle impairment in COPD.

Techniques employed include invasive measurement of respiratory pressures, cardiopulmonary exercise testing and the use of magnetic nerve stimulation to obtain non-volitional measures of muscle function. His work has been funded by The Wellcome Trust, The European Union, The British Lung Foundation and The Moulton Foundation.

Within Imperial College he is involved in research with The Centre for Pervasive Sensing to develop more sophisticated integrated physiology and activity sensors to monitor patients in their home environment. 

Pulmonary Rehabilitation

The Pulmonary Rehabilitation Group, based at Harefield Hospital, work closely with one of the largest clinical pulmonary rehabilitation services in the UK. Research activities are broadly split between “acute” and “stable” patients with chronic respiratory disease, especially chronic obstructive pulmonary disease (COPD). There are two main themes to the “acute” work:
1) Physiological biomarkers that predict prognosis following acute exacerbation of COPD (AECOPD); and 
2) Post-hospitalisation pulmonary rehabilitation. The group were strongly involved in the two major UK trials in this area, and maintain an interest in improving uptake or providing viable alternatives to post-hospitalisation pulmonary rehabilitation.

The themes of the “stable” patient work are developing practical physical performance and health status outcome measures for patients with chronic respiratory disease such as COPD and idiopathic pulmonary fibrosis (IPF) using pulmonary rehabilitation as a model, longitudinal studies in patients with COPD and IPF with a particular emphasis upon understanding skeletal muscle phenotype and geriatric syndromes such as sarcopenia and frailty, pharmacological and non-pharmacological methods to augment the benefits of pulmonary rehabilitation, clinical trials in COPD and guideline / national audit work In pulmonary rehabilitation.