[Sleep apnea syndrome in Japan: analysis of pathophysiology and nasal continuous positive airway pressure effectiveness].

Forty eight Japanese sleep apnea syndrome (SAS) patients, whose apnea-hypopnea index (AHI) was more than 30 times/hr. from 5 university hospitals (46 males, 2 females) were enrolled in this study to analyze the characteristics of the disorder and the effectiveness of nasal continuous positive airway pressure (nCPAP) effectiveness. Although the severity of excessive daytime sleepiness (EDS), depressive state, and ventricular premature beats caused by SAS seemed milder in Japanese than reported Caucasian patients, the prevalences of hypertension and glucose intolerance were quite high: 50 and 30% respectively. Treatment with nCPAP for 3 months was completed in 41 of 48 enrollees, a compliance rate of 85.4%, which was substantially higher than studies from Western countries. nCPAP treatment normalized about 50% of hypertensive patients and more than half of glucose intolerant patients. Moreover, EDS, driving ability, the severity of arrhythmia, and so forth were all improved with nCPAP. We, therefore, conclude that 1) SAS could differ between Japanese Caucasians in terms of clinical features resulting from SAS and 2) treatment with nCPAP is effective and should be considered as first-line treatment for patients with moderate to severe SAS, as reported in Western countries.