PURPOSE: Clinical studies have established the association of obstructive sleep apnea (OSA) with oxidative stress. Oscillations of oxygen levels during sleep occur in OSA. This study evaluates the degree of sleepiness associated with sleep induced hypoxemia in mild to moderately severe OSA contrasted with alveolar hypoventilation (AH) as measured by the Epworth Sleepiness Scale (ESS) scores of 10 or greater as a function of ODI.
METHODS: 36344 baseline PSG studies performed at SleepMed 2009-2010 were reviewed. ESS was administered prior to each study. Oxygen desaturation index (ODI) was measured at equal to or greater than the 4% level during total sleep time. Studies were included with the following criteria: mild nonsignificant sleep disordered breathing (NSDB)- RDI<15, ODI<10, and time <90% less than 10 minutes; moderately severe OSA- RDI>15, ODI>10, and nadir oxygen less than 85%; AH- RDI <10, ODI <10, nadir oxygen<85 and time below 90%>10 minutes.
RESULTS: NSDB=9526/36344 patients (26%) with 5216 (55%) females and 4310 (45%) males with mean age of 47(18); BMI=31(8); ESS=9.3(6); RDI=7(4); nadir oxygen=86(5); ODI=3(2); time <90% min=2(2).Moderately severe OSA= 12255/36344 patients (34%) with 4670 (38%) females and 7585 (62%) males with mean age of 55 (15); BMI=35(12); ESS=10(6); RDI=42(24); nadir oxygen=78(8); ODI=31(21); time <90% min=49(66).AH= 1470/36344 patients (4%) with 951(65%) females 519 (35%) males with mean age of 56 (16). ESS score= 9.8 (6); BMI = 33(9); RDI= 6(3); nadir oxygen=80 (29); ODI= 4(2); time<90% (min) =103(100).T-tests comparing ESS scores of patients with NSDB with AH p=0.0008; NSDB with moderately severe OSA p=2.86E-39; AH with moderately severe OSA p=0.003.
CONCLUSION: Our results demonstrated that oscillations in oxygen levels seen in NSDB to moderately severe OSA vs. sleep induced alveolar hypoventilation produce sleepiness as measured by ESS. Sleep apnea patients tended to be sleepier. Gender differences were seen with a higher frequency in females with AH and NSDB. In the moderately severe sleep apnea group a more male predominance with a higher BMI was observed.
CLINICAL IMPLICATIONS: Oscillations in oxygen levels are associated with sleepiness.
DISCLOSURE: Richard Bogan, No Financial Disclosure Information; No Product/Research Disclosure Information