Progression to chronic obstructive pulmonary disease (COPD): Could it be prevented by manual therapy and exercise during the ‘at risk’ stage (stage 0)? Roger M. Engel * , Subramanyam Vemulpad Department of Health and Chiropractic, Macquarie University, Bldg E7A 222, Balaclava Road, Sydney, NSW 2109, Australia article info Article history: Received 3 October 2008 Accepted 7 October 2008 summary A number of predisposing factors are recognised as increasing the risk of developing chronic pulmonary obstructive disease (COPD). There is increasing recognition that COPD may be an inflammatory disease with systemic consequences. However, the trigger for the transition from ‘at risk’ (stage 0) to COPD state remains unclear. The current approach to intervention for the ‘at risk’ group is risk factor avoidance. We propose that if interventions shown to improve chronic respiratory symptoms in COPD sufferers could be applied to the ‘at risk’ group, then moderation or even reversal of the changes typical of this transition becomes a possibility. Exercise training has been shown to be beneficial at all stages of COPD. Mobility of the chest wall influences lung function. We hypothesise that the application to ‘at risk’ individuals (stage 0) of therapeutic interventions known to improve chronic respiratory symptoms and cardiovas- cular function in mild/moderate COPD (stages 1 and 2) could delay progression of the disease (i.e. man- ifestation of mild/moderate COPD). If the hypothesis were confirmed, the potential to delay or even prevent the onset of COPD would be feasible. Crown Copyright Ó 2008 Published by Elsevier Ltd. All rights reserved. Introduction Two large studies have recently documented a high prevalence of COPD [1,2]. The situation is set to deteriorate as the condition is projected to become the fifth most frequent cause of death world- wide by 2020 [3]. Cigarette smoking is recognised as the main predisposing factor for increasing the risk of developing COPD [4,5]. However, only a minority of heavy smokers develop chronic airflow limitation [6–8]. Other possible predisposing factors include a history of childhood respiratory tract infections [9,10], occupational expo- sure [11,12], low birth weight [13], air pollution [14,15] and diets low in anti-oxidants [16]. There is increasing recognition that COPD may be an inflamma- tory disease with systemic consequences [17,18]. COPD itself may cause systemic inflammation [19,20] or inflammation in the respi- ratory system may trigger airflow obstruction in susceptible indi- viduals [21]. In the latter case, the inflammation precedes the onset of symptoms of chronic lung disease [18]. It is possible that adverse airway remodelling occurring as a result of childhood respiratory infections could render the person more susceptible to respiratory conditions such as COPD later in life [6,22,23]. In summary it would appear that apart from smoking, the trigger for the transition from non-diseased to COPD state remains unclear. Investigating the period when diagnosis can first be confirmed and declining lung function begins to accelerate beyond what is attributable to age alone could provide further insight into the ori- gins of the condition and hence possible intervention. Persons ‘at risk’ of developing COPD (stage 0) are often charac- terised by normal spirometry in the presence of chronic symptoms such as cough and sputum production [4]. The current approach to intervention for people in this group is risk factor avoidance. The recommended interventions are health education, smoking cessation and influenza vaccination [4,5]. Exer- cise training has been shown to benefit all levels of COPD [24,25] by improving cardiovascular fitness, muscle function, muscle strength and endurance [5]. However, the role of exercise in pre- venting COPD remains to be tested in the ‘at risk’ group [4,5,26]. We propose that if interventions shown to improve chronic respiratory symptoms in COPD sufferers could be applied during the period when alterations in lung architecture associated with COPD begin i.e. the ‘at risk’ or stage 0, then moderation or even reversal of those changes becomes a possibility. If these interven- tions were low risk, low cost, effective and amenable to implemen- tation in all parts of the world [27], considerable impact on the future burden of the disease would result. Hypothesis. It is hypothesised that the application to ‘at risk’ individuals (stage 0), of therapeutic interventions known to 0306-9877/$ - see front matter Crown Copyright Ó 2008 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.mehy.2008.10.017 * Corresponding author. Tel.: +61 2 9850 6387; fax: +61 2 9850 9389. E-mail address: rengel@els.mq.edu.au (R.M. Engel). Medical Hypotheses 72 (2009) 288–290 Contents lists available at ScienceDirect Medical Hypotheses journal homepage: www.elsevier.com/locate/mehy