Sleep apnoea may increase, and PAP use decrease, COVID-19 risk

Individuals with obstructive sleep apnoea (OSA) may have an increased risk of COVID-19, with the risk reducing with adherence to positive airway pressure (PAP) therapy, according to a study presented at ATS 2021.

“We were surprised that OSA patients with high adherence [to] PAP had lower infection rates than [individuals] who did not even have OSA,” said study author Dr Dennis Hwang, medical director, KP SBC Sleep Medicine, Kaiser Permanente and co-chair, sleep medicine, Southern California Permanente Medical Group, California, US. “This further supports a direct physiologic benefit of PAP therapy,” he added.

The investigators retrospectively analysed a sleep medicine database from Kaiser Permanente Southern California between 2015 and 2020 which contained electronic health record information, sleep study data, and remotely collected daily PAP data of patients who were assessed for sleep disorders. Participants were categorized according to their OSA and PAP therapy status (untreated: PAP <2 hours/night; treated: PAP ≥2 hours/night; moderately treated: PAP 2–3.9 hours/night; well treated: PAP ≥4 hours/night).

Participants were 81,932 adults (mean age 54 years, 39.8 percent female). Of these, 1.8 percent (n=1,493) had a confirmed diagnosis of COVID-19, with 0.3 percent (n=224) requiring hospitalization. Sixty-one of the hospitalized patients (0.07 percent) required intensive care and/or died.

Compared with the group of participants without OSA (COVID-19 rate of 1.7 percent), those with untreated OSA had elevated COVID-19 rates, with the rate rising with increasing OSA severity (2, 2, and 2.4 percent for mild, moderate, and severe OSA, respectively). Conversely, COVID-19 rate was lower among participants whose OSA was treated compared with those without OSA (1.4 percent; p<0.0001). [ATS 2021, abstract A1108]

Greater adherence to PAP therapy was also associated with a reduced rate of COVID-19 (1.7 and 1.3 percent among moderately and well treated participants, respectively) vs untreated participants or those without OSA.

The risk of COVID-19 was lower among those without OSA vs those with untreated OSA (adjusted odds ratio [OR], 0.82, 95 percent confidence interval [CI], 0.70–0.96). PAP treatment reduced the risk of COVID-19 by 18 and 31 percent among participants with OSA who were moderately treated (OR, 0.82, 95 percent CI, 0.65–1.03) and well treated (OR, 0.69, 95 percent CI, 0.59–0.80) compared with untreated participants.

Presence of OSA or adherence to PAP did not appear to affect hospitalization rate, intensive care admission, or death.

Certain factors were associated with an increased risk of COVID-19 including obesity (ORs, 1.71 and 2.09 for BMIs 30–35 and ≥35 kg/m², respectively, vs 18.5–25 kg/m²), a higher Charlson Comorbidity Index (OR, 1.32 for >2 vs 0), and Black and Hispanic ethnicity (ORs, 1.49 and 2.23 vs White). In contrast, increasing age was tied to a lower risk of COVID-19 (OR, 0.89 per 5-year increase).

According to Hwang, multiple reasons may explain the association between OSA and PAP adherence and COVID-19 risk, including both biological and behavioural factors.

“The higher rate of infection with more severe OSA and the shared medical risk factors between OSA and COVID-19 such as male [sex], obesity, and presence of cardiovascular diseases supports a biological influence, perhaps through impact on respiratory function, airway inflammation, and sleep fragmentation,” he said.

“On the other hand, while older age clearly increases COVID-19 severity, our finding that older age was associated with a reduced infection rate supports a behavioural explanation. Patients with OSA tend to be older, and older patients may be more adherent to social distancing, masking, and less risky social behaviours,” he added.

“Reduced upper and lower airway obstruction, improved lung expansion, improved mobilization of secretions, and PAP heated humidification may be potential protective mechanisms,” he continued.

However, the reduced risk of COVID-19 with increasing age and the increased risk in certain ethnicities may also hint at a “socioeconomic influence,” he said.