(min; 466 ± 6 at baseline vs 460 ± 4 on S1, 467 ± 2 on S2, and 457 ± 2 on S3; p = 0.30). SI was 24% lower (7.5 ± 0.9 vs 5.7 ± 0.7, p = 0.02) and kg decreased by 22% (1.8 ± 0.2 vs 1.4 ± 0.2, p = 0.02); SWS suppression was associated with a decrease in HFn (%; 39.3 ± 3.7 vs 32.1 ± 4.3, p = 0.04), and an increase in LFn (%; 60.7 ± 3.7 vs 67.9 ± 4.3, p = 0.04), sympatho-vagal bal- ance (LF/HF) (1.8 ± 0.3 vs 2.6 ± 0.5, p = 0.02). Conclusion: Our findings provide the first evidence that, in healthy young adults, disruption of sleep quality with reduction of SWS that is typical of normal aging and OSA, is associated with decreased glucose tolerance and insulin sensitivity, and increased daytime cardiac sympa- thetic activity. Disturbed sleep quality may be implicated in the increased risk for diabetes in OSA and aging. doi:10.1016/j.sleep.2006.07.135 P327 Mean nocturnal oxygen saturation is predictive of non-alcoholic fatty liver disease (NAFLD) activity score (NAS) in patients with morbid obesity Poonam Mishra 1 , Michael Weinstein 2,7,* , Siva Vithiananthan 3,7 , James H. Grendell 1,7 , George K. Turi 4 , Arzu Buyuk 4 , Louis Ragolia 5,7 , Simcha Pollack 6 , Karen Norowski 3 , Shiobhan R.Weston 1,8 1 Division of Gastroenterology, Hepatology and Nutri- tion, Jamaica, NY, USA 2 Division of Pulmonary and Critical Care, Jamaica, NY, USA 3 Departments of Medicine and Surgery, Jamaica, NY, USA 4 Department of Pathology, Jamaica, NY, USA 5 Vascular Biology Institute, Jamaica, NY, USA 6 Winthrop University Hospital, St. John’s University, Jamaica, NY, USA 7 Stony Brook University School of Medicine, Stony Brook, NY, USA 8 Columbia New York- Presbyterian Hospital, NY, USA Background: Non-alcoholic fatty liver disease (NAFLD) is now recognized as the hepatic manifestation of meta- bolic syndrome. Obesity is a major risk factor for both obstructive sleep apnea (OSA) and insulin resistance. Recent studies have shown that OSA is independently associated with hypertension, impaired glucose tolerance, dyslipidemia, and insulin resistance. However, studies investigating the possibility of an association between OSA and NAFLD have yielded conflicting results. Objectives: To determine if there is a correlation between OSA and NAFLD in patients with morbid obesity. Methods: Forty-six patients undergoing bariatric sur- gery were enrolled. All patients underwent polysomnog- raphy prior to surgery. Body mass index (BMI), blood pressure, fasting serum liver enzymes, glucose and lipid profiles were measured pre-operatively. Excess alcohol intake, >2 drinks/day (males) and >1 drink/day (females) was excluded as were other causes of liver dis- ease including serology for viral hepatitis. Liver biopsies were scored by a single histopathologist using the recently validated NAS scoring system. Results: Mean BMI was 46.9 kg/m 2 SD ± 7.6 in our cohort. Thirty-eight patients (82.6%) had OSA; severe OSA (apnea–hypopnea index; AHI > 40/h) was present in 19.6% (n = 9); 26.1% (n = 12) had moderate OSA (AHI > 20–40/h); 37% (n = 17) had mild OSA (AHI P 5–20/h), and 17.4% (n = 8) of patients had no OSA (AHI < 5/h). Thirty-five patients (76%) had NAFLD including simple steatosis (n = 6), steatosis with inflam- mation/± fibrosis (n = 24) and non-alcoholic steatohepa- titis (NASH; n = 5). Using Spearman’s rank correlation, severity of OSA as measured by AHI did not independent- ly predict NAS score (r = 0.3, p < 0.06). However, mean nocturnal oxygen saturation (MNOS) was related to NAS score (r = À0.4. p < 0.05). Using independent t-tests to compare means, patients with OSA had significantly higher ALT (44 vs. 35, p < 0.0021) and lower MNOS val- ues (94.24 vs. 96.03, p < 0.02) compared to patients with- out OSA. Although there was a trend towards higher NAS scores in OSA patients, this did not reach statistical significance (2.66 vs. 1.38, P < 0.08). Conclusion: Mean nocturnal oxygen saturation is a sig- nificant predictor of NAS score in morbidly obese patients. AHI was not predictive of NAS score in this study. These results suggest that nocturnal hypoxemia, as measured by MNOS, is an important contributor to liver injury in these patients. doi:10.1016/j.sleep.2006.07.136 P328 Association of ACE gene polymorphism in asymp- tomatic patients with OSAS in a Brazilian population R.G. Koyama 1,2 , M.T. De Mello 1,2,* , M.V. Rossi 1,2 , S.E. Ferreira 1,2 , R.A. Boscoli 1,2 , E. Rutter 1,2 , A. Bailoni-Neto 1,2 , L.R.A. Bittencourt 1 , L.M. Luchesi 1 , M. Pedrazzoli 1 , S. Tufik 1 1 Psychobiology Department of the Federal University of Sa ˜ o Paulo (UNIFESP), Brazil 2 Research Center of Psychobiology and Exercise, CEPE, Brazil Objective: Based on previous studies that suggest the association between Angiotensin Converting Enzyme gene (ACE) polymorphism I/D and obstructive sleep apnea syndrome (OSAS), this study verified this associ- ation in asymptomatic sleepiness individuals. Methods: Thirty-eight males and 51 females mean age 29.17 ± 0.7, sedentary, not complaining of their sleep quality and self related asymptomatic for sleep disorder. The quality of sleep was subjectively measured by the S54 Abstracts / Sleep Medicine 7 (2006) S1–S127