Asthma patients with obesity have a unique phenotype: a subanalysis of the Turkish adult asthma registry.

Objective: The obese-asthma phenotype has gradually increased in the last few years. We aimed to assess the differences between obese and non-obese patients with asthma.

Methods: This research is a subanalysis of the Turkish Adult Asthma Registry (TAAR). Clinical presentation, disease control, severity, and demographics of obese and non-obese (normal-weight, overweight) patients were compared.

Results: The obesity rate in TAAR was 32.2% (n = 619/1919; 18-83 years; 527 F/92 M). Patients with asthma and obesity had higher rates of childhood obesity, longer symptom duration, later onset of asthma, and more severe asthma. These patients were more likely to be female, older, less educated, and live in rural areas. Patients with obesity had more scheduled visits and emergency visits compared with non-obese patients, but similar asthma control, oral corticosteroid use, hospitalizations, intensive care unit admissions, and unscheduled visits. They also had a higher frequency of T2-high but lower frequency of possible T2-low phenotypes compared with normal-weight asthmatics. The risk of severe asthma in patients with obesity was 6.04 times higher for allergic than non-allergic patients and 3.58 times higher for the T2-high phenotype than for possible T2-low phenotypes. A one-unit increase in the asthma control test reduced the risk of severe asthma by 22%.

Conclusions: A good definition of this phenotype is important to ensure that appropriate treatment strategies are implemented to achieve the control goal. We also believe that prevention of childhood obesity is an effective and pivotal strategy to achieve the goal of asthma control.