HYPERTENSION AND OBSTRUCTIVE SLEEP APNEA: IS THE BERLIN QUESTIONNAIRE A VALID SCREENING TOOL?: PP.32.273

Abstract

Obstructive sleep Apnea Syndrome (OSA) increases the risk of cardiovascular diseases, in particular hypertension. The gold standard for the diagnosis of OSA is polysomnography (PSG). Berlin questionnaire (BQ) is a validated approach to indirectly quantify the risk of OSA in a general population. Aim of our study was to explore the actual prevalence of OSA in a group of unselected hypertensive patients and to evaluate sensitivity and specificity of BQ in determining the risk of OSA in this population vs PSG. Methods. 151 subjects referred to the Hypertension Center of our Institute, were also administered the BQ; 66 of these also performed a cardiorespiratory PSG (Embletta device). 17 subjects were excluded because inconsistency or lack of questionnaire responses or technical problems during PSG. Results: BQ suggested a high risk of OSA in 96% of cases. PSG showed that 59.2% of subjects presented an apnea-hypopnea index (AHI) > 5, and 40.8% an AHI <5. The two groups were comparable by gender and age and subjective daytime sleepiness. BMI was significantly higher in patients with OSA (OSA 30.3 kg/m2, non-OSA 27.1 kg/m2, p < 0.05). Application of BQ as compared to PSG showed an high sensitivity (0.94) but an extremely low specificity (0), if the BQ is interpreted according to standard guidelines (use of 3 categories of questions, international criteria). If we exclude from the analysis the 3th category (not appropriate in this population because specifically asking for presence of hypertension or BMI >30), the sensibility is 0.88 and the specificity increases significantly until to 0.39. Conclusions: Our data confirm the high prevalence of OSA in patients with hypertension. For the first time we compare BQ and PSG data in hypertensive patients. Our data suggest that caution is needed when applying BQ in this population because of inappropriate questions in patients with known hypertension. A specific version of BQ applicable to hypertensive subjects is thus needed for a reliable screening of OSA in this population.