0506 Falling Asleep Versus Feeling Sleepy in Sleep Apnea Screening

Abstract

influence of age on sleep architecture and daytime sleepiness in a large sample of OSAS patients. Methods: We enrolled 2399 patients with OSAS (apnea-hypopnea index, AHI ≥ 5) divided into two age groups: over 65 (n = 1180, mean age 70.2 ± 4.5 years), and 65 or under (n = 1219, mean age 50.1, ± 10.9 years). Subjective daytime sleepiness, reflected by the Epworth sleepiness scale (ESS), and polysomnographic parameters were recorded and compared between the two groups. Results: There were no significantly differences regarding gender, BMI, daytime sleepiness (31.9% vs 46.7% had ESS>10) between the elderly and younger patients with OSAS, but the incidence of comorbidities such as hypertension and other cardiovascular diseases was significantly higher (p<0.001). The sleep architecture was significantly worse in elderly OSAS patients with lower SE (%) (p<0.001), REM (%) (p<0.001), and higher NREM (%) and WASO (p<0.001) compared with the younger patients. The percentage of SWS, apnea hypopnea index (AHI), and oxygen desaturaion index (ODI) had no significantly difference in the two groups. The mean and the lowest oxygen saturation and arousal index were significantly decreased in elderly OSAS patients (p<0.001). Conclusion: Our results suggest that objective sleep quality was more impaired in elderly compared to younger-aged patients. Additionally the prevalence of sleepiness in the elderly group was low and elderly had more cardiovascular comorbitities. Introduction: Sleep-disordered breathing (SDB) is associated with sleepiness, high blood pressure, and cardiovascular events. Cardiovascular associations have been linked to oxygen desaturation. Less is known regarding SDB associations with sleepiness. Different physiologic associations (e.g. arousal vs desaturation) of SDB events may result in different pathobiologic outcomes. Methods: 2,112 nocturnal polysomnograms (PSGs) from 1,022 subjects in the Wisconsin Sleep Cohort were analyzed with our automated algorithm, which was developed to detect breathing disturbances (decrease of 30% in nasal airflow for at least 10 seconds, without a concomitant increase in oral flow) and desaturations. Breathing disturbance events were time-locked to desaturations, resulting in 2 indices: desaturating (H-BDI) and non-desaturating (NH-BDI) events. Systolic and/or diastolic hypertension was used as a measure of cardiovascular health. Measures of subjective (Epworth Sleepiness Scale) and objective (2,981 MSLTs from a subset of 865 subjects) sleepiness were analyzed. Additional, clinically relevant variables were accounted for in modeling associations. Results: H-BDI, but not NH-BDI, correlated strongly with SDB severity indices that included hypoxia (r≥0.89, p≤0.001 with ODI 3% and AHI with 4%-desaturations). Each twofold increase in desaturation-associated events was associated with an increased risk of hypertension (3% ODI OR=1.06, 95% CI=1.00-1.12, p<0.05) and daytime sleepiness (β=0.20 ESS score, p<0.0001; β=-0.20 min in MSL on MSLT, p<0.01). Non-desaturating events were more stron...