P121 Role of Ambulatory Blood Pressure Monitoring (Abpm) in the Evaluation of Patients With Suspected Sleep Apnea

Background and Objective: Obstructive sleep apnea (OSA) often coexists with hypertension. Ambulatory blood pressure monitoring (ABPM) is essential for detecting significant blood pressure fluctuations, especially during nighttime. This study seeks to assess the role of ABPM in identifying OSA. Methods: We analyzed a database of patients with suspected OSA using the STOP-BANG questionnaire at a cardiology center from July 2020 to April 2024. Anthropometric characteristics, blood pressure behavior through ABPM, and sleep patterns via polysomnography were evaluated. The influence of risk predictors on OSA development was assessed using multinomial logistic regression. Results: The study included 38 men (50.6%) and 37 women (49.3%); 48 hypertensive patients (64%) and 27 without hypertension (27%). The average STOP-BANG score was 3.8. Of these, 92% had some degree of OSA. The mean age was 60±13.2 years. Neck circumference (NC) and total apnea-hypopnea index were 37.5 cm and 19.7 events/hour, respectively, with a predominance of REM OSA. Only NC and nocturnal diastolic pressure were significant variables. For the development of moderate OSA, NC showed significant relative risk ratios (RRR) (p=0.045). Severe OSA development was influenced by mean nocturnal diastolic blood pressure (MNDAP) and NC, with significant RRRs (p=0.007 and p=0.041, respectively). This means that for each mmHg increase in nocturnal diastolic pressure, the risk of severe OSA increases by 1.3 times compared to healthy patients, predominantly during REM sleep. Conversely, increased daytime diastolic pressure decreases this risk by 25%. Conclusions: An increase in mean nocturnal diastolic pressure measured by ABPM is a significant predictor of severe OSA development. This underscores ABPM's importance in evaluating patients with suspected OSA. While the STOP-BANG questionnaire is useful for initial OSA suspicion, it has limitations in identifying the most severe cases, necessitating tools like ABPM for more accurate assessment. The use of ABPM improves accuracy in detecting severe OSA and enhances understanding of hypertension phenotypes’ pathophysiology. Table 1. Obstructive Sleep Apnea (OSA) Severity Classification and Its Correlation with Mean Nocturnal Diastolic Blood Pressure (MNDAP), Mean Daytime Diastolic Blood Pressure (MDDAP), and Neck Circumference (NC)