Obstructive sleep apnoea of mild severity: should it be treated?

To provide guidance in the management of mild obstructive sleep apnoea syndrome (OSAS) in the context of a very high prevalence, poor correlation with symptom profile, and lack of evidence that mild OSAS significantly contributes to comorbidity or early mortality.

Mild obstructive sleep apnoea defined by hourly frequency of apnoeas or hypopnoeas (AHI) between 5 and 15 affects up to 35% of the general adult population but is much less prevalent when associated daytime symptoms are included. The poor correlation between symptoms and AHI complicates diagnosis and reports that mild OSAS is not significantly associated with comorbidity casts doubt on clinical significance. The diagnosis is complicated by night-to-night variability and by underestimation of AHI in ambulatory sleep studies that do not include sleep assessment. Active management of mild OSAS can be symptom-driven and offers a broad range of options. Lifestyle measures may be sufficient in many cases and mandibular advancement devices or positional therapy may be more effective in mild OSAS. Sleepy patients with low AHI may warrant a trial of continuous positive airway pressure therapy to establish the relationship between sleep disordered breathing and symptoms.

Management of mild OSAS can focus on symptom relief to the individual patient.