Oscillometry testing can identify asthma and obesity patients with subclinical airway reactivity, according to a study in CHEST. It may also identify patients with obesity who have subclinical abnormalities without any clinically diagnosed lung disease. Researchers identified two phenotypes among patients with obesity and asthma, with one appearing in an early onset allergic form and the other in a late-onset nonallergic form. The study may prompt reassessment of disease evaluation for those with severe asthma and obesity.

Asthma and obesity are two common health conditions that affect millions of people worldwide. While they may seem unrelated at first glance, recent studies have shown that there is a complex relationship between the two. In fact, research suggests that certain phenotypes – or variations – of asthma may be more common in individuals who are overweight or obese. This has important implications for the diagnosis, treatment, and management of both conditions. In this article, we will explore the different phenotypes of asthma and how they relate to obesity, and what this means for those affected by these conditions.


A study published in CHEST suggests that using oscillometry testing, physicians may be able to identify patients with asthma and obesity who have a phenotype that may be related to worse symptoms and more severe disease. The study involved 53 patients with class III obesity who were evaluated for bariatric surgery, including 31 with asthma and 22 controls with no lung disease. Compared with the control patients, the patients with asthma had slightly higher serum IgE and lower FEV1, FVC, FEV1/FVC, reactance at 5 Hz measured by oscillometry (X5), and lower expiratory reserve volume, as well as higher residual volume, difference between resistance at 5 Hz and 19 Hz (R5-10) and area under the reactance curve (AX). In response to a methacholine aerosol challenge, the patients with asthma had greater decrements in FEV1 and FVC than the control patients. They also responded at lower doses and had greater absolute magnitudes of R5, R5-19, X5 and AX in addition to a lower peak dose of methacholine than the control group. The study found that although changes in impedance parameters in response to methacholine did not distinguish the control patients from those with asthma in a population of patients with obesity, those with asthma responded at slightly lower concentrations of methacholine, suggesting that obesity may predispose patients to reactivity in peripheral airways regardless of whether they have asthma. The researchers concluded that these results further suggest two distinct physiological phenotypes of asthma with obesity, with one appearing in an early onset allergic form and the other in a late-onset nonallergic form.


In conclusion, the relationship between asthma and obesity is complex and multi-factorial, with varying phenotypes among patients. Understanding these unique clinical features can aid in the development of personalized treatment plans and improve the overall management of asthma in obese individuals. By recognizing and addressing the distinct factors contributing to asthma symptoms in each patient, clinicians can provide more effective and targeted care, ultimately leading to improved outcomes and quality of life. As research in this field continues to evolve, it is imperative that healthcare providers stay informed and adapt their practices accordingly to provide the best possible care for their patients.