Sleep apnea and oxygen saturation in adults at 2640 m above sea level.
OBJECTIVE
To describe the SpO2 in wakefulness, sleep and during the apnea-hypopnea in adults living in Bogotá, located at 2640 m above sea level.


METHODS
Descriptive observational study in adults referred for polysomnogram (PSG). A normal Apnea hypopnea index (AHI) was defined as ≤5 and obstructive sleep apnea (OSA) was classified as mild (AHI 5-15), moderate (AHI 15-30), and severe (AHI >30). T-test or ANOVA test for SpO2 differences between groups was used.


RESULTS
1799 patients, 33% women. 222 (12.8%) did not have OSA (normal IAH), 268 (14.9%) mild OSA, 315 (17.5%) moderate ,and 993 (55.2%) severe. In all cases a low SpO2 (SpO2<90%) was found. The SpO2 was lower when the AHI was higher, in wakefulness, in non-REM and in REM (p<0.001). For all grades of severity, SpO2 decreased significantly from wakefulness to non-REM sleep and to REM sleep (p<0.001). Patients with severe OSA had higher desaturation during wakefulness (85.2±6.6%), non-REM sleep (83.1±7.7%), REM sleep (78.8±10.2), and during events (75.1±9.1%).


CONCLUSIONS
Patients with OSA at 2640 m have nocturnal desaturation lower than 88%, which decreases with higher severity of OSA. The clinical impact of sleep disorders at this point may be greater than at sea level and should be studied.
Sleep Laboratory, Fundación Neumológica Colombiana (FNC), Colombia.
Maria Angelica
MA
Bazurto Zapata
Sleep Laboratory, Fundación Neumológica Colombiana (FNC), Colombia.
Elida
E
Dueñas Meza
Sleep Laboratory, Fundación Neumológica Colombiana (FNC), Colombia.
Claudia
C
Jaramillo
Sleep Laboratory, Fundación Neumológica Colombiana (FNC), Colombia.
Dario
D
Maldonado Gomez
Sleep Laboratory, Fundación Neumológica Colombiana (FNC), Colombia.
Carlos
C
Torres Duque
High altitude; Oxygen saturation; Sleep apnea