Impact of comorbidities on asthma

Abstract

Asthma is a common and serious illness with suboptimal outcomes of care. Epidemiological studies show certain comorbidities occurring more frequently than expected with asthma, with some being associated with poor control and a differential response to therapy options. This review summarizes the evidence of clinically important comorbidities, focusing on the best-explored conditions, including rhinitis and rhinosinusitis, anxiety and depression, obesity, gastroesophageal reflux, smoking and dysfunctional breathing. The evidence of epidemiological and pathophysiological associations for these comorbidities is explored, and the practical therapeutic implications are considered. Comorbidities are important for clinicians treating asthma as they may be markers of patients at risk of poor outcomes, they may point to specific effective treatment options and they are important to researchers as possible confounding factors in clinical trials.

Keywords::

• anxiety
• asthma
• comorbidity
• dysfunctional breathing
• gastroesophageal reflux
• hyperventilation
• obesity
• outcome
• rhinitis
• rhinosinusitis
• smoking

Financial & competing interests disclosure

Neither M Thomas nor any member of his close family has any shares in pharmaceutical companies. In the last 3 years he has received fees for acting as a consultant for Merck, Sharpe and Dohme, Schering and GlaxoSmithKline (GSK) and has received speaker’s honoraria for speaking at sponsored meetings from the following companies marketing respiratory and allergy products: AstraZeneca, Boehringer Inglehiem, GSK, MSD, Schering-Plough and Teva. He has received honoraria for attending advisory panels with Altana, Astra Zeneca, BI, GSK, MSD, Merck Respiratory, Schering-Plough and Teva. He has received sponsorship to attend international scientific meetings from GSK, MSD and Astra Zeneca. He has received funding for research projects from GSK, MSD and Astra Zeneca. He holds a research fellowship from Asthma UK.

D Price has consultant arrangements with Aerocrine, Boehringer Ingelheim, Dey Pharmaceuticals, GSK, Merck generics, Merck, Sharpe and Dohme, Novartis, Schering-Plough and Teva. He or his team have received grants and research support for research in respiratory disease from the following organisations: the UK National Health Service, Aerocrine, AstraZeneca, Boehringer Ingelheim, GSK, Merck, Sharpe and Dohme, Novartis, Pfizer, Schering Plough and Teva. He has spoken for Boehringer Ingelheim, GSK, Merck, Sharpe and Dohme and Pfizer. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.