NT-proBNP (inactive form of brain natriuretic peptide) in preliminary detection of cardiovascular complications of obstructive sleep apnoea. Design: Consecutive OSA subjects, qualified to CPAP treatment. Methods and measurements: Sleep questionnaire with Epworth sleepiness scale and full polysomnography (PSG) or polymesam study (PM). Evaluation of plasma NT-proBNP was performed in all subjects before CPAP treatment (normal value of NT-proBNP was <125 pg/ ml). Results: We studied 174 consecutive OSA patients (138 males and 36 females) qualified to CPAP therapy (mean age – 53.7 ± 10.7 years, AHI – 43.4 ± 23.2, BMI – 35.8 ± 6.2). To assess relations between NT-proBNP, sever- ity of OSA and cardiovascular diseases we divided patients in two subgroups: 1st with higher NT-proBNP (36 pts, 20.7%) and 2nd with normal NT-proBNP (138 pts, 79.3%). Comparison of both subgroups in table below. Variable Higher NT- proBNP Normal NT- proBNP p Age (years) 59.6 ± 8 52.2 ± 10.9 p < 0.001 AHI (n/h) 43.1 ± 22.2 43.5 ± 23.5 NS SaO 2 mean (%) 88.3 ± 6.4 89.5 ± 4.9 NS BMI (kg/m 2 ) 36.1 ± 6.3 35.8 ± 6.2 NS Coronary artery disease (n/%) 17 (47.2%) 26 (18.8%) p = 0.0004 Atrial fibrillation (n/%) 10 (27.8%) 4 (2.9%) p < 0.00001 Heart failure (n/%) 13 (36.1%) 9 (6.5%) p < 0.00001 Arterial hypertension (n/%) 30 (83.3%) 97 (70.3%) NS Stroke (n/%) 2 (5.6%) 7 (5.1%) NS Multiple linear regression analysis revealed significant correlation between NT-proBNP and atrial fibrillation (b = 0.49, p < 0.0001), heart failure (b = 0.26, p = 0.0004), coronary artery disease (b = 0.25, p = 0.001) and stroke (b = À0.19, p = 0.01). Conclusions: Increased plasma NT-proBNP concentra- tion in OSA subjects was related to older age and higher frequency of atrial fibrillation, coronary artery disease, and heart failure. doi:10.1016/j.sleep.2006.07.142 P334 The impact of continuous positive airway pressure in non-obese patients with obstructive sleep apnea and sys- tolic heart failure Takatoshi Kasai 1,* , Koji Narui 1 , Tomotaka Dohi 2 1 Toranomon Hospital, Sleep Center, Tokyo, Japan 2 Toranomon Hospital, Cardiovascular Center, Tokyo, Japan Objectives: Obstructive sleep apnea (OSA) may affect the progression of heart failure (HF). Continuous posi- tive airway pressure (CPAP) had been proven as an effective therapy for OSA and underlying HF. Although most of patients with OSA are obese (O), there are a lot of non-obese (NO) patients with OSA in oriental popu- lation. However, the efficacy of CPAP for HF in such NO population remains unknown. Materials and methods: HF patients who revealed left ventricular ejection fraction (LVEF) <50% underwent polysomnography. Then patients with OSA, defined as apnea–hypopnea index (AHI) = 15/h and of which more than 50% were obstructive events, were initiated CPAP. Patients were divided into two groups according to their body mass index (BMI) = 25 (O) or <25 (NO). Systolic (SBP) and diastolic (DBP) blood pressure, LVEF, plasma brain natriuretic peptide (BNP), and New York Heart Association class (NYHA) were assessed at the baseline and 3 months later. Results: Overall 30 male were assessed. The baseline char- acteristics were similar between O (n = 14) and NO group (n = 16) except BMI. At 3 months later, BMI revealed no significant changes in both groups. LVEF showed signif- icant improvements in both groups; LVEF: 41 ± 8 to 50 ± 8 (P = 0.0003) in O, 42 ± 10 to 44 ± 9% (P = 0.04) in NO. The improvement of LVEF was significantly greater in O (P = 0.02). SBP, DBP, BNP, and NYHA class showed significant reductions only in O; SBP: 131 ± 6 to 123 ± 6 (P < 0.0001), DBP: 89 ± 11 to 82 ± 12 (P < 0.0001), BNP: 178 ± 78 to 134 ± 56 (P = 0.04), and NYHA : 2.4 ± 0.5 to 1.5 ± 0.5 (P = 0.003) in O. Conclusion: The treatment with CPAP for OSA had an efficacy for underling HF even in NO. Furthermore, the reduction of LVEF was significantly smaller in NO than in O. The left ventricular pressure overload (expressed by BNP) and afterload (expressed by SBP and DBP) were not significantly reduced in NO patients. doi:10.1016/j.sleep.2006.07.143 P335 Heat shock protein 70 in peripheral blood mono- cytes of sleep apnea patients. Link with TNF-a expression Larissa Dyugovskaya, Orit Golan, Peretz Lavie, Lena Lavie The Lloyd Rigler Sleep Apnea Research Laboratory, Faculty of Medicine, Technion, Haifa, Israel Objectives: Heat shock proteins (HSPs) are specific pro- teins induced in cells by various stresses including hyper- thermia, hypoxia, and oxidative stress. The HSP70 family protects the cells from oxidative stress or hypox- ia/ischemia. Design: The links between basal and induced intracellu- lar HSP70 and TNF-a expression were investigated in monocytes of OSA patients. S58 Abstracts / Sleep Medicine 7 (2006) S1–S127