The CORE syndrome: an overlap of severe asthma, obstructive sleep apnea, rhinosinusitis, and esophageal reflux

Asthma, obstructive sleep apnea (OSA), rhinosinusitis, and esophageal reflux are conditions that may overlap, forming a syndrome known as CORE. Whenever clinical remission of severe asthma (SA) is not achieved, it is essential to investigate the presence of comorbidities, in particular the presence of OSA that may lead to the diagnosis of CORE syndrome.

The study was conducted on naive patients with SA and concomitant rhinosinusitis and esophageal reflux, referred to our institute since 2018. Patients who did not experience clinical remission were investigated for OSA through a home sleep apnea test. Subsequently, for those diagnosed with OSA, continuous positive airway pressure (CPAP) was proposed and was re-evaluated after 12 months.

Six patients with CORE syndrome were enrolled. The mean apnea–hypopnea index (AHI) was 33.25 ± 20.13 events/h, oxygen desaturation index (ODI) was 28.95 ± 19.95 events/h, and time in bed with SaO2 < 90% (T₉₀) was 26.40 ± 27.22% for which continuous positive airway pressure (CPAP) treatment was proposed but only 3 out of 6 patients accepted. After 12 months, all CPAP-treated patients manifested a significant reduction in daytime sleepiness (ESS score was 6.33 ± 3.8), an improvement in ACT score (+ 8 (+ 32%), + 9 (+ 36%), and + 14 (+ 56%) points), a discontinuation of oral corticosteroids (OCS), an absence of exacerbations, and an improvement of lung function leading to clinical remission of asthma.

Whenever facing SA patients, non-responders to therapy, it is important to suspect the presence of CORE syndrome; in particular, the detection and subsequent treatment of OSA would seem to improve the outcome of such patients.