Prevalence of Complex Sleep Apnea Among Japanese Patients with Sleep Apnea Syndrome

Abstract

Sleep apnea syndrome (SAS) is basically divided into two types: obstructive and central SAS. Recently, the concept of complex SAS has been advocated. Complex SAS is defined as SAS that initially manifests as primarily obstructive SAS, but is characterized by the frequent central apneas after the removal of upper airway obstruction. To determine the prevalence and clinical significance of complex SAS among Japanese patients with SAS, 1,312 patients with SAS were enrolled in this study. Diagnosis of central SAS was made based on diagnostic polysomnography, and differentiation of obstructive SAS from complex SAS was made from polysomnographic findings for treatment with continuous positive airway pressure, which resolved upper airway obstruction. As a result, obstructive SAS was found in 1,232 of 1,312 patients with SAS (93.9%) and central SAS was found in 14 patients (1.1%). The overall prevalence of complex SAS was 5.0% (n = 66). The prevalence of complex SAS among 1,218 male and 94 female patients with SAS were 5.3% and 1.1%, respectively. Patients with complex SAS had significantly higher apnea/ hypopnea indices than patients with either obstructive or central SAS, but were similar in both mean age and average body mass index to obstructive SAS patients. There were no significant between-group differences in numbers of patients with clinical complications including hypertension, cardiac diseases, or cerebrovascular diseases. In conclusion, the prevalence of complex SAS in Japanese SAS patients is 5.0%, which is lower than previously reported prevalence of complex SAS in the USA and Australia. obstructive sleep apnea syndrome; central sleep apnea syndrome; hypertension; cardiac disease; cerebrovascular disease.

A prospective polysomnographic study on the evolution of complex sleep apnoea

“…This is close to results from MORGENTHALER et al [4] and LEHMAN et al [14], but higher than prevalence rates found in recent studies by ENDO et al [12] and JAVAHERI et al [13] (table 7). We could not replicate male dominance and slightly younger age in CompSA, as found by most other authors.…”

“…Our sleepiness scores are similar to other results [4,13]. Our sample's age profile differs only from the study of ENDO et al [12], who studied younger patients. All other studies determined CompSA on titration nights or in the titration part of split-night studies.…”

“…Furthermore, the sample in the study by LEHMAN et al [14] included patients with central sleep apnoea. There are also genetic differences with a probable impact on sleep and breathing [27] between the Japanese sample in the study by ENDO et al [12] and our German Caucasian population.…”

“…As sleep stages are not evenly distributed over the course of a night [11], full-night studies might yield more representative results. 2) Studies were conducted retrospectively [4,10,[12][13][14] and/or with small sample sizes [3,14]. 3) Only patients with complex or predominantly central apnoeas with CPAP [3,13,15] at treatment initiation were followed.…”

Obstructive Sleep Apnea and Kidney Disease: A Potential Bidirectional Relationship?

“…[13][14][15][16][17][18] The number of patients with OSA in the United States is estimated at 15 million. 19 However, some believe that these rates may be an underestimate, since rates of obesity, which is a major risk factor for OSA, has been steadily increasing over recent decades.…”