Is asthma a risk factor for Obstructive Sleep Apnea (OSA)?

Asthma as a Risk Factor for Obstructive Sleep Apnea

Asthma is a significant risk factor for the development of obstructive sleep apnea (OSA), with asthmatic patients having approximately 40% higher risk of developing OSA compared to non-asthmatic individuals. 1

Evidence Supporting Asthma as an OSA Risk Factor

• Prospective epidemiological data from the Wisconsin Sleep Cohort Study demonstrates that participants with asthma experienced a 27% incidence of OSA over a 4-year follow-up period, compared to only 17% in those without asthma (adjusted relative risk 1.39) 1
• Longer asthma duration correlates with increased OSA risk, with each 5-year increment in asthma duration associated with a 7% higher risk of developing OSA 1
• More severe or difficult-to-control asthma is independently associated with OSA, with an odds ratio of 4.36 2
• Asthma not only increases the risk of OSA but also increases daytime sleepiness in OSA patients as measured by the Epworth Sleepiness Scale 2

Pathophysiological Mechanisms Linking Asthma and OSA

• Common risk factors between asthma and OSA include obesity, rhinitis, and gastroesophageal reflux disease (GERD) 3, 4
• Shared inflammatory pathways exist between the two conditions, with both involving systemic inflammatory responses and respiratory tract inflammation 4
• Neuromechanical reflexes triggered by upper airway collapse in OSA may worsen bronchial hyperreactivity in asthma 4
• Corticosteroid medications used to treat asthma may contribute to weight gain, which is the principal risk factor for OSA 5

Clinical Implications

• OSA complicates asthma management by worsening lung function, particularly in children with asthma who show decreased forced expiratory volume in one second (FEV1) when OSA is present 2
• The presence of OSA should be considered in patients with poorly controlled asthma, particularly those who are overweight or obese 6
• Treating OSA with continuous positive airway pressure (CPAP) in asthmatic patients improves both clinical and perceived asthma control 7
• After CPAP treatment, good asthma control increased from 41% to 70% of patients, with significant improvements in Asthma Control Test scores 7

Screening and Diagnostic Considerations

• Patients with moderate-to-severe or difficult-to-control asthma should be screened for OSA 2
• Formal evaluation for OSA should be considered in children presenting with chronic rhinitis and other risk factors associated with sleep-disordered breathing 6
• Polysomnography is the gold standard for diagnosing OSA in asthmatic patients 8
• Assessment should include evaluation of common risk factors such as obesity, nasal obstruction, and GERD 3

Management Approaches

• Weight management is crucial for patients with both asthma and OSA or at risk for OSA 5
• CPAP therapy is the first-line treatment for OSA and may improve asthma control in patients with both conditions 7
• Treatment of nasal obstruction and rhinitis may improve both conditions 6
• Intranasal corticosteroids can reduce nasal airway resistance and apnea-hypopnea frequency in patients with both OSA and rhinitis 6

The bidirectional relationship between asthma and OSA highlights the importance of considering both conditions in clinical practice, especially in patients with suboptimal disease control despite appropriate therapy.