Extra-pulmonary characteristics of people with COPD and lung hyperinflation and the effects of lung volume reduction

About the Project

Background: For some people with chronic lung disease high lung volumes (hyperinflation) contribute to extreme breathlessness, severely curtailed exercise capacity, and fatigue. For suitable individuals, lung volume reduction (LVR) via endobronchial or surgical intervention can reduce lung volumes, increase exercise capacity, improve quality of life and reduce mortality (NETT Trial, AJRCCM, 2011).

There is relatively little known about the impact of LVR beyond the lungs. Nutritional status, body composition and skeletal muscle function are likely to be important factors (Kim, AJRCCM, 2012; Greening et al, AJRCCM, 2015; Swallow et al, Thorax, 2007). We do not fully understand the mechanisms driving an individuals’ recovery (or failure to recover) exercise capacity after LVR: nutritional status; muscle function; exercise performance; muscle mass; and importantly muscle quality have not been carefully characterised. The role of Pulmonary Rehabilitation in decision making, preparation for, and recovery from LVR interventions is also unclear. There is also a paucity of data on the impact of LVR on cardiac function; both the direct influence via reduction in intrathoracic pressure and the indirect effects that may occur through changes in exercise behaviors are worthy of investigation.

Aim: To study the extra-pulmonary characteristics of people with lung hyperinflation and relate these to recovery of physical function after lung volume reduction (LVR) treatment. This project will produce detailed extra-pulmonary phenotyping in people with hyperinflation accessing the chronic obstructive pulmonary disease (COPD) clinical service.

Glenfield Hospital represents one of the largest regional centers for LVR in the UK. This PhD project will recruit patients accessing the complex COPD service and those referred through the LVR clinical pathway to address the following questions: 1) How does hyperinflation influence systemic features of COPD including skeletal muscle, nutritional status, and cardiac function? 2) What are the changes in skeletal muscle function, mass and quality following LVR and removal of ventilatory limitation? 3) Does the reduction of hyperinflation following LVR improve cardiac muscle remodeling and diastolic filling?

Drawing on the experience of supervisors and collaborators within the University of Leicester the successful candidate will collect and analyse data using techniques such as systematic literature review; clinical measures (e.g. nutritional status, regional muscle mass by multi-frequency bioelectrical impedance); and research methods (e.g. MRI for muscle quality and cardiac function, DEXA body composition, cardiopulmonary exercise testing, isokinetic dynamometry for muscle strength and fatigue, tri-axial accelerometry for assessing habitual physical activity).

Supervisor contact details:

Primary supervisor: Dr Lorna Latimer ll203@leicester.ac.uk

Secondary supervisors: Professor Michael Steiner michael.steiner@leicester.ac.uk Dr Neil Greening neil.greening@leicester.ac.uk