Abstract: Objective To investigate the effects of obstructive sleep apnea-hypopnea syndrome (OSAHS) and age on sleep
architecture and the therapeutic effects of continuous positive airway pressure (CPAP). Methods We retrospectively analyzed
222 subjects undergoing polysomnography (PSG) for snoring, who received CPAP under PSG on the next day following the
initial PSG. The sleep architecture of the subjects in different age groups and in groups with different severities of OSAHS was
analyzed before and after adjustment for apnea-hypopnea index (AHI) or age. The sleep architecture and ventilation function
of the patients with OSAHS were also analyzed after CPAP. Results N3 sleep showed the strongest correlation with AHI
(r=-0.361), and REM sleep and wake after sleep onset (WASO) were the most strongly correlated with age (r=-0.211 and 0.216,
respectively). The 4 age groups showed significant differences in sleep efficiency (P<0.001), N1 (P=0.015), N2 (P=0.013) and
REM (P=0.030) sleeps, and WASO (P=0.001) but not in AHI (P=0.185). REM sleep decreased and WASO increased with an
increasing age. The sleep efficiency and architecture were still significant different after adjustment for AHI. In 4 groups with
different severity of OSAHS, N1, N2 and N3 sleeps were significant different after adjustment for age (P=0.011, 0.017, 0.001). In
patients with moderate or severe OSAHS, N3 sleep increased with the increase of AHI. After CPAP for OSAHS, N1 and N2
sleeps significantly decreased, and N3 and REM sleeps increased (P<0.001). Conclusions Between OSAHS and age, REM sleep
and WTSO are more importantly affected by age, while OSAHS more strongly affects N3 sleep. CPAP can improve the sleep
quality of patients with OSAHS.