Dysfunctional breathing is a common comorbidity in patients with severe asthma, and is associated with increased patient anxiety and depression.
Eve Denton, MBBS, MPH
While there may not always be a biological cause for dysfunctional breathing (DB), it is a common comorbidity in severe asthma. A recent study has found that DB can also be associated with sinus issues, some psychological disorders, and unemployment.
DB is a collection of breathing disorders that demonstrate a change in breathing pattern that results in breathlessness, according to the American Academy of Allergy, Asthma and Immunology (AAAAI). There are multiple breathing patterns that may present themselves, including hyperventilation, deep sighing, thoracic-dominant breathing, and mouth breathing. However, the condition is still highly enigmatic, and diagnosis can be difficult.
Investigators, led by Eve Denton, MBBS, MPH, of Alfred Hospital in Melbourne, Australia, have conducted past research detailing the high occurrence of DB among those with severe asthma. For this current study, their goal was to identify other risk factors in this population that may contribute to the development of DB.
Participants included 157 adult patients under care in Alfred’s asthma program from June 2014 through December 2017. Symptoms included severe or frequent asthma exacerbations despite treatment, inadequate control of asthma symptoms, unclear diagnosis, severe airflow obstruction, or asthma management issues.
Patients completed asthma and comorbidity questionnaires at baseline, lung function tests, and skin prick tests. Asthma control was evaluated using the six-item Asthma Control Questionnaire (ACQ 6) and quality of life using Asthma Quality of Life Questionnaire (AQOL).
DB was diagnosed with a Nijemgen Questionnaire score greater than 23 and with matching clinical symptoms that include excessive dyspnea. Additional comorbidities that were assessed included psychiatric history (using the Hospital Anxiety and Depression Scale [HADS]), atopy, allergic rhinitis, chronic rhinosinusitis, sleep apnea, gastroesophageal reflux, and vocal cord dysfunction (VCD).
Almost half (47%) of the participants experienced DB, with female patients more likely to be diagnosed (24 vs. 20; P= .04). Those with DB also had a higher chance of being unemployed (44% vs. 61%; P= .04), have higher exacerbations (3 vs. 2.5; P= .037), worse asthma control (ACQ 6 2.8 vs. 2.1; P= .001), and worse quality of life (AQOL 3.8 vs. 4.6; P< .001).
Overall, psychiatric comorbidity was significant for depression (29%) and anxiety (25%). Patients with DB had more anxiety (41% vs. 11%; P< .001) and depression (44% vs. 18%; P= .001). HADS scores were also higher for anxiety (10 vs. 5.3; P< .001) and depression (7.6 vs. 3.6; P< .001). Sinus symptoms, anxiety, and depression were also independent risk factors for DB.
“Dysfunctional breathing is a common but under-recognized cause of excessive breathlessness in [the difficult asthma] population and it is important to identify due to the potential for treatment,” investigators wrote. “Breathing retraining in those with mild to moderate asthma improves quality of life and recent data from our group suggests similar benefits in more severe asthma.”
Also of note: there was no association found between lung function impairment or inflammatory biomarker levels (IgE, atopic status, and eosinophil count) and DB diagnosis. Investigators noted this emphasizes the need to explore DB in patients with severe asthma regardless of poor lung function or inflammatory phenotype.
The study, “Factors Associated with Dysfunctional Breathing in Patients with Difficult to Treat Asthma,” was published online in The Journal of Allergy and Clinical Immunology.