Introduction: Obstructive sleep apnea (OSA) repre-sents a highly prevalent pathology that, left untreated, can cause important complications: cardiac arrhyth-mia, heart failure, high blood pressure, myocardial ischemia, pulmonary hypertension, stroke, type 2 dia-betes, depression, anxiety. Continuous positive airway pressure (CPAP) represent the gold standard for treat-ment of OSA. Treatment with CPAP abolishes episodes of OSA and also reduces sympathetic activity. This de-creases daytime sleepiness, augments cognitive functi-on and improves the quality of life.

Objective: To study the improvement of polygraphy indexes after CPAP and to evaluate the influence of co-morbidities on the severity of OSA.

Methods: T his is a prospective, observational, longi-tudinal, analytic, cohort study. From January 2016 to August 2016 at ‘Leon Daniello’ Clinical Hospital of Pul-monology in Cluj-Napoca, all patients with suspicion of OSA who addressed to the clinic, were included. Of the 150 patients from the study group, 93 patients with OSA were included, aged 60 (58;64) years, sex ratio female/male 1:4. Patients have performed respirato-ry polygraphy examination in 3 different steps: at the time of diagnosis, during titration and at three months checkup, after treatment with CPAP. They also fulfilled these examinations: biological samples (blood count, lipid profile, blood sugar); chest X-ray; spirometry; electrocardiogram; echocardiography; otorhinolaryn-gology examination.

Results: Most of patients are male, urban residence, obese grade I or III, NYHA class II of heart failure, with stage 2 arterial hypertension, dyslipidemia, con-sume coffee and have severe sleep apnea. There has been a considerable improvement in all respiratory pa-rameters right after titration and an even greater im-provement during 3 months control after CPAP thera-py (p<0.001). Sleep apnea severity was correlated with obesity (r=0.269; p=0.009). In women, sleep apnea was correlated with BMI (r=0.592; p=0.005), age (r=0.516; p=0.01), neck circumference (r=0.584; p=0.005). AHI (apnea-hypopnea index) (p=0.005), Epworth Sleepi-ness Scale (p=0.04) and the total number of respiratory events (p=0.009) decreased more in patients without hypertension compared to those with it. Also, AHI de-creased more in patients without heart failure then in those with it (p=0.05).

Conclusions: Worldwide, prevalence of obstructive sleep apnea (OSA) increases significantly. Sleep apnea patients associated multiple comorbidities. All para-meters derived from respiratory polygraphy and also Epworth scale, significantly improved at the 3-months checkup, after CPAP treatment. Sleep apnea is directly linked to high cardiovascular mortality and morbidity.