Research Article

Clinical Features and Contributing Factors of Excessive Daytime Sleepiness in Chinese Obstructive Sleep Apnea Patients: The Role of Comorbid Symptoms and Polysomnographic Variables

Table 3

PSG variables of the total OSA patients and the patients with different severities of EDS.

TotalNon-EDSMild to moderate EDSSevere EDSFp

Sleep efficiency (%)84.8 ± 12.383.5 ± 12.987.3 ± 10.3c88.2 ± 10.3a11.032<0.0001
WASO (min)49.0 ± 49.352.6 ± 52.843.9 ± 41.0c34.8 ± 39.5a5.5370.004
SL (min)28.7 ± 27.231.0 ± 27.626.4 ± 27.716.1 ± 14.4a,b10.119<0.0001
N1 (%)42.7 ± 19.240.7 ± 17.346.4 ± 22.6c48.5 ± 19.5a10.775<0.0001
N2 (%)44.6 ± 14.745.5 ± 14.243.5 ± 15.340.3 ± 16.7a4.4050.012
N3 (%)4.2 ± 6.44.6 ± 6.63.1 ± 5.1c4.6 ± 7.34.8670.008
REM (%)8.7 ± 6.29.2 ± 6.27.9 ± 5.8c6.6 ± 6.0a7.922<0.0001
MAI (h−1)44.4 ± 20.640.8 ± 19.451.5 ± 20.7c51.4 ± 22.9a27.643<0.0001
AHI (h−1)46.7 ± 24.736.6 ± 23.254.4 ± 22.8c55.7 ± 24.7a58.831<0.0001
TAmax (s)60.2 ± 27.356.2 ± 25.768.7 ± 28.7c66.1 ± 28.5a19.781<0.0001
Nadir SpO271.8 ± 13.474.7 ± 11.366.5 ± 15.1c64.6 ± 15.3a45.422<0.0001
Mean SpO292.9 ± 3.493.7 ± 2.691.7 ± 4.0c90.4 ± 5.2a50.413<0.0001
ODI (h−1)43.1 ± 25.836.9 ± 24.154.8 ± 24.3c57.2 ± 26.2a55.829<0.0001
SIT90 (%)16.0 ± 22.912.3 ± 16.622.6 ± 32.4c26.5 ± 23.5a25.205<0.0001

Data are presented as mean ± SD. aComparisons between non-EDS versus severe EDS groups (); bcomparisons between mild to moderate EDS versus severe EDS groups (); ccomparisons between non-EDS versus mild to moderate EDS groups (). EDS: excessive daytime sleepiness; WASO: wake after sleep onset; SL: sleep latency; REM: rapid eye movement; MAI: microarousal index; AHI: apnea-hypopnea index; TAmax: the longest time of apnea; ODI: oxygen desaturation index; SIT90: saturation impair time below 90%.