Immunological characteristics and management considerations in obese patients with asthma

Abstract

Obesity is associated with severe, poorly controlled asthma that does not respond as well to therapy as asthma in leaner asthmatics. Important insights gained from animal models of obesity and asthma suggests that different forms of obesity may lead to different manifestations of airway disease: obesity is associated with both innate increased airway reactivity and altered responses to aeroallergen and pollutant challenges. In humans, at least two broad groups of obese asthmatics have been recognized: one that is likely unique to obesity and another that is likely lean allergic asthma much complicated by obesity. This article will discuss what we have learned about the immunological and pathophysiological basis of asthma in obesity from animal and human studies, and how this might guide therapy.

Keywords:

• adiponectin
• airway hyperreactivity
• asthma
• diet
• leptin
• obesity
• phenotypes

Financial & competing interests disclosure

The authors were supported by Grants from the National Institutes of Health. AE Dixon serves on Data and Safety Monitoring Boards for Boehringer Ingelheim and Roche. AE Dixon receives grant funding from the National Institutes of Health, American Lung Association and Pfizer. ME Poynter receives grant funding from the National Institutes of Health. 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.

Key issues

• Obesity is a complex disease, and the mode and type of obesity affect manifestations of disease in the airway.

• Obesity produces fundamental changes in innate and adaptive immunity.

• Obesity is associated with innate airway reactivity, in the absence of any provocative agent, and without obvious airway inflammation.

• Two phenotypes of asthma have been identified in obese people with asthma (late-onset, non-allergic airway disease and early onset allergic airway disease), but there are likely to be many more.

• These different phenotypes of asthma in obesity will require customized treatment based on the underlying pathophysiology of the disease.

• Obese asthmatics have altered responses to medications, they do not respond as well to glucocorticoids. Treatment trials targeting specific phenotypes of obese asthmatic are needed.