Physical inactivity in patients with COPD: the next step is … action.

Abstract

Physical activity is being increasingly recognised as a factor that modulates co-morbidities and adverse outcome in patients with COPD. Attention to physical inactivity is therefore of the utmost importance, particularly in patients who are not yet severely impaired by their lung function and are managed in primary care. Enhancing physical activity in these patients may have potential spin-offs, with important improvements in the burden of COPD co-morbidities. Many of the ‘typical COPD co-morbidities’ are indeed associated with lack of physical activity. In this issue of the PCRJ, Fastenau and co-workers report low physical activity levels in a group of patients followed-up in primary care. In these patients with GOLD stage I and II disease, 33% of patients had a step count of around 5000 or less, which is conventionally seen as one of the benchmarks for ‘sedentarism’. This study is yet another call for action to healthcare providers managing these patients – patients who have, at first sight, ‘mild to moderate’ COPD. Measuring physical activity is no luxury reserved for lifestyle clubs. Physical activity should be considered a ‘vital sign’, and the study by Fastenau et al. shows this clearly. The authors also conclude that there is a poor relation between exercise capacity – as assessed by the six minute walk test (6MWT) in this study – and physical activity. This poor relation can perhaps be explained to some extent by methodological factors in their study: possible selection bias with selection based on impaired exercise tolerance and low physical activity; for the 6MWT, the corridor not being of standard length and the possibility that there was no practice walking test; and, in terms of the activity monitor data and analysis, seasonal variation was not taken into account for the correlation analyses and there was no report of compliance with monitor use. However, the poor relation between exercise capacity and physical activity behavior shown in this study should not come as a surprise. Leidy et al. speculated years ago that physical activity and functional capacity were two different concepts. When functional capacity is larger (i.e. there is better 6MWT performance) patients have more choice regarding engagement in physical activity. Physical activity is indeed a complex endpoint, influenced by several factors. The factors best understood intuitively are personal factors (including genetic), exercise-related factors, and psychological factors. Other factors influencing patients’ choice whether or not to engage in physical activity are linked to interpersonal aspects (social support, as an example), environmental factors (climate, social environment and architectural) and policy (e.g. public transport, incentives for physical activity). So, in comparison with other studies performed in ‘milder’ (or primary care) COPD patients, the present study confirms for primary care practitioners that physical activity is low in many patients with COPD. Low physical activity levels are the best guarantee that patients will develop co-morbidity (on top of their many pack-years of smoking). What should one do next? Firstly, assessment of physical activity is of the utmost importance. This is also what Fastenau and co-workers conclude. Questionnaires may help to identify severely inactive patients, but they largely fail to provide a correct reflection of physical activity across the whole spectrum. Physical activity monitors have become more readily available, and in the European IMI-JU PROactive project (www.PROactiveCOPD) some of these monitors are identified as being valid tools for the assessment of physical activity in patients with COPD. The use of activity monitors in primary care has been proposed and validated by others. In the future, the use of smart phones containing accelerometers may help in profiling patients at little cost and, importantly, with low time investment. Secondly, primary care physicians and healthcare providers in general should be aware of the risks of physical inactivity. An attributed mortality of around 10% cannot be underestimated. All healthcare providers should be aware that inactive patients with COPD will eventually develop co-morbidities which will complicate significantly their disease management. Lastly, enhancing physical activity is a challenge, and there is no ‘miracle solution’. Simple interventions such as the use of pedometers with agreed physical activity targets may help patients to enhance physical activity levels. Increasingly, we will see health technology applications appear which promote physical activity. Pilot studies have been undertaken with these techniques in patients with mild COPD. Concerted efforts between healthcare providers, policy makers and social support initiatives are likely to be successful in the long term. One example is an initiative in Catalunia where, in collaboration with the city engineers, walking circuits were designed in the city to fit the needs of patients with COPD. The use of these walking trails did increase physical activity in patients who completed a pulmonary rehabilitation programme. Such community-based efforts should be fostered, since they may benefit not just patients with COPD but also patients with obesity or those at risk of developing Type II diabetes. Guidelines should exist at a local level on when and how to refer patients with COPD for physical activityenhancing interventions. Such guidelines do exist in the Netherlands, where the study by Fastenau et al. took place. In the absence of Physical inactivity in patients with COPD: the next step is ... action