From the Guidelines
The main OSA phenotypes can be broadly categorized into anatomical, non-anatomical, and combined types, with anatomical phenotypes involving physical obstructions, non-anatomical phenotypes involving factors like low respiratory arousal threshold, high loop gain, and poor upper airway muscle responsiveness, and combined phenotypes presenting with both anatomical and non-anatomical factors 1.
Key Characteristics of OSA Phenotypes
- Anatomical phenotypes are characterized by craniofacial abnormalities, enlarged tonsils, or excess soft tissue in the upper airway that physically obstructs breathing during sleep.
- Non-anatomical phenotypes include those with low respiratory arousal threshold, high loop gain, and poor upper airway muscle responsiveness.
- Combined phenotypes show both anatomical and non-anatomical factors, requiring a comprehensive approach to treatment.
Importance of Phenotyping in OSA Management
Understanding these phenotypes is crucial for personalized treatment approaches, as it allows clinicians to tailor interventions to the specific needs of each patient, potentially improving outcomes and quality of life 1.
- Patients with primarily anatomical OSA may respond well to CPAP therapy or surgical interventions.
- Those with non-anatomical factors might benefit from positional therapy, oral appliances, or pharmacological interventions targeting specific physiological mechanisms.
- Proper phenotyping enables clinicians to move beyond the traditional one-size-fits-all approach to OSA management and develop more effective, individualized treatment strategies, which is in line with recent guidelines and consensus statements 1.
From the Research
Main OSA Phenotypes
The main OSA phenotypes can be categorized based on different characteristics, including:
- Symptom-based subtypes, such as "excessively sleepy" and "disturbed sleep" 2, 3
- Polysomnographic subtypes, distinguished by respiratory event association with hypoxemia, arousals, or both 3
- Phenotypes based on pathophysiologic risk factors, such as arousal threshold, craniofacial morphology, and chemoreflex sensitivity 2
- Phenotypes based on clinical manifestations and consequences, such as cardiovascular disease risk and response to therapy 3
Examples of OSA Phenotypes
Examples of OSA phenotypes include:
- Excessive daytime sleepiness OSA, which has significant prognostic and treatment implications 2
- Disturbed sleep OSA, which may have a different impact of CPAP on symptoms and health-related quality of life 3
- OSA with comorbidities, such as obesity, hypertension, and diabetes, which may require a multidisciplinary approach to management 4
Importance of OSA Phenotypes
Identifying OSA phenotypes is important for: