Objective: Obstructive sleep apnea （OSA） has a high prevalence among sleep-related respiratory disorders, and the main symptoms are snoring, apnea, daytime sleepiness, and lack of deep sleep. As a treatment method, an oral appliance （OA） has been established as a treatment for OSA according to clinical guidelines. Although the severity of OSA tends to be evaluated by the apnea-hypopnea index （AHI）, it is necessary to evaluate OSA not only based on the AHI value but also based on the clinical features. Therefore, it is important to evaluate OSA from multiple perspectives. We attempted cluster analysis to clarify the clinical features of OSA patients.
Methods: The subjects were 381 patients who visited the Center of Dental Sleep Medicine between June 2017 and June 2020. From the medical records, we extracted the values of age, BMI, presence/absence of hypertension, AHI, lowest percutaneous arterial oxygen saturation （Lowest SpO2）, and subjective evaluation of sleepiness （ESS）. Patients were classified using cluster analysis.
Results: As a result of cluster analysis, OSA patients were classified into four clusters according to the characteristics of the clinical features. Cluster 1 had few subjective symptoms of sleepiness, Cluster 2 had a high comorbidity rate of hypertension, Cluster 3 had sleepiness, and Cluster 4 had high AHI, low value of Lowest SpO2, and strong sleepiness. It was clarified that there are various clinical features of OSA as well as the clinical features of typical severe OSA cases, such as Cluster 4.
Conclusions: It is suggested that a multifaceted evaluation is needed, not just the AHI value. It is also important to set treatment goals that should be emphasized for each characteristic of the cluster.
