Asthma, like myriad other diseases, results when its risk factors successfully coalesce, narrowing a person’s airways, causing limited airflow, and creating mucus and wheezing. Poor air quality, genetic history, allergies, and more, are at play here. When the patient has asthma that cannot be managed effectively, death could ensue.

And asthma, like other diseases, has numerous comorbidities, including obesity, rhinitis, obstructive sleep apnea. A global team from the UK, Australia, Serbia, Singapore, and the US set out to understand the interplay between these comorbidities and asthma severity, and which comorbidities were most to blame for that severity. Ramesh J. Kurukulaaratchy, BM, DM, MRCP, University of Southampton, Southampton, England, discussed the creation of a new tool to scale these comorbidities with Medscape Medical News.

Medscape Medical News: Is difficult-to-treat asthma becoming more prevalent? If so, why?

Kurukulaaratchy: Asthma became more common in many Westernized countries over the last part of the 20th century. It has since stabilized in some countries, but its prevalence has increased in many developing countries where it had been rare. We think this growth in asthma is due to a complex interplay of environmental exposures and vulnerability to inherited genes.

Regarding difficult-to-treat asthma, we suspect that it is present in about 1 in 6 patients with asthma and that it, too, has become more common as asthma prevalence has increased. Also, over the past 25 years the awareness of difficult-to-treat asthma has grown, resulting in more diagnoses. Specialist centers to treat these patients have opened in many countries.

Medscape Medical News: Why did you create MiDAS?

Kurukulaaratchy: As a practicing clinical specialist who has been treating patients with difficult-to-treat asthma for many years, I recognized early on that these patients rarely have asthma alone; most also have multiple health problems. It seemed that as the number of their health problems rose, their asthma severity and healthcare outcomes worsened. That led our clinical practice to develop multidisciplinary healthcare teams to support the wider healthcare needs of our patients.

We also suspected that if specific comorbidities increased asthma severity — and if they occurred in combination — the asthma severity status would be worsened. (This table spells out the comorbidities analyzed.) If these comorbidities could be successfully treated, these outcomes could significantly improve asthma and the patient’s general health.

So we developed MiDAS, or multimorbidity on difficult-treat asthma using a novel score. We want to detect these comorbidities and recognize their risks at the patient level, to ultimately serve as a treatment prompt. First, we identified which conditions were associated with a composite multidimensional measure of asthma severity, then we combined those into MiDAS, then assessed the validity of MiDAS in several asthma patient populations by working with colleagues in multiple countries.

Medscape Medical News: Have many physicians visited the MiDAS app?

Kurukulaaratchy: Some, but the MiDAS paper was just published this month. I use it in the clinic to explain to patients why we need to address their comorbidities. The concept of a score seems to resonate, and it helps patients to put matters into context. We hope other healthcare professionals find the same clarity.

Medscape Medical News: You discuss holistic treatment of these patients in your paper, writing that they get suboptimal treatment with just an airway-centric approach. So how do you envision holistic treatment?

Kurukulaaratchy: As stated, we created multidisciplinary teams to support difficult-to-treat asthma patients — usually nurses, psychologists, physiotherapists, pharmacists, and doctors — all with expertise in severe asthma. Perhaps the most common model would be to have the asthma specialist characterize a patient’s multimorbidity components and then arrange referrals to specialists including ENT specialists, gastroenterologists, endocrinologists, sleep specialists, and dermatologists. Complex cases may call for more coordinated treatment.

Medscape Medical News: In your paper, nearly half of all cohorts developed asthma as adults, so presumably the rest developed it as children? Are some comorbidities more prominent in those who grow up with asthma? Do these ingrained comorbidities make asthma more difficult to treat in adults?

Kurukulaaratchy: This is a fascinating question. We know from our previous work that some subgroups who develop both asthma and other health conditions in early life have more difficult-to-treat asthma in adulthood — allergic subtypes of asthma associated with other allergic conditions like eczema, rhinitis, and food allergy. But for others with early-onset asthma it may be associated with obesity or psychophysiological conditions. We suspect that deeply ingrained comorbidities do make asthma more difficult to treat but we don’t have definitive evidence yet.

Medscape Medical News: Because obesity or overweight is such a problem in children and adults, who often develop prediabetes and diabetes, is the asthma that develops any different, or any more severe (despite medication adherence) than the asthma that develops in people without overweight or obesity? And vice versa: If the asthma develops first, and the person gains weight because of lack of activity, is that asthma different?

Kurukulaaratchy: Yes, obesity is a highly relevant comorbidity for patients with asthma and clearly associated with worse asthma status and health outcomes. For instance, we know that patients with “obese asthma” may not respond as well to asthma biologic treatments. We are still early on in understanding the different types of “obese asthma.” Broadly speaking, some patients may have obesity prior to developing asthma and they tend to have greater metabolic dysfunction. We think that they may have more prominent metabolic-driven inflammatory pathways that adversely affect their airways.

But this explanation could be oversimplified. Other patients with asthma develop obesity because of physical deconditioning and overexposure to treatment like oral steroids. It isn’t clear yet how this form of asthma differs from that which arises in people with obesity first. One hope is that by supporting patients with asthma better, (eg, avoiding excess reliance on oral steroids, treating other comorbidities contributing to breathing difficulty in a holistic manner and providing appropriate patients with early access to biologics) this form of “secondary obese asthma” might be significantly reduced in the future.