0996 Cardiovascular Crisis Signal: Hypoxic Burden is the Critical Biomarker Linking Intermittent Hypoxemia to Sustained BP Elevation

Abstract Introduction Obstructive Sleep Apnea (OSA) is associated with chronic sympathetic activation and an increased cardiovascular risk, including sustained elevation of blood pressure (BP). Hypoxic Burden (HB) has been proposed as a quantitative indicator of the intensity and duration of hypoxemia during sleep, which may more accurately reflect the hemodynamic alterations related to OSA. Objective: To evaluate the association between the Hypoxic Burden and blood pressure levels in patients with OSA. Methods Methods: This was a cross-sectional study nested within a cohort evaluating 36 individuals, 58.1% of whom were women, with a mean age of 53.95 + 11.86 years. Patients diagnosed with OSA were included. Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) measurements (mmHg) were collected, along with the Hypoxic Burden, measured using the formula considering the area under the oxyhemoglobin desaturation curve greater than 3%. Results Results: A predominance of Pardo (mixed-race) individuals was observed (n = 18; 41.9%). The mean Body Mass Index (BMI) was 30.77 + 8.06 kg/m². Mean SBP was 133.00 + 21.11 mmHg and mean DBP was 82.67 + 13.48 mmHg. A positive correlation was found between HB and SBP values (r = 0.559; p = 0.030). Similarly, a significant positive correlation was observed between HB and DBP (r = 0.339; p = 0.038). A difference in mean DBP was observed between patients with and without elevated Hypoxic Burden: 80.4 + 10.1 mmHg and 86.3 + 15.7 mmHg, respectively. The same pattern was noted for mean SBP: 125.8 + 15.7 mmHg and 138.1 + 19.4 mmHg, respectively. Conclusion Conclusion: Our study establishes that Hypoxic Burden (HB) is the primary quantifiable driver of blood pressure dysfunction in Obstructive Sleep Apnea (OSA). The significant and positive correlation observed between HB and both systolic and diastolic blood pressure levels (SBP, DBP) strongly suggests that the intensity of intermittent hypoxemia is a superior and more biologically relevant indicator of cardiovascular risk than the mere event count (AHI). Support (if any)