Apnea-Hypopnea Index Versus Hypoxic Burden as Predictors of Blood Pressure Response to Continuous Positive Airway Pressure Treatment in Patients With Obstructive Sleep Apnoe

Obstructive sleep apnea (OSA) is associated with increased cardiovascular risk and hypertension. While continuous positive airway pressure (CPAP) therapy reduces blood pressure (BP), its effect shows substantial interindividual variability. Hypoxic burden (HB) has been proposed as a potentially superior predictor of cardiovascular outcomes compared to the apnea-hypopnea index (AHI). In this retrospective study, 141 patients with OSA underwent in-laboratory polysomnography and initiated CPAP therapy. Office BP and clinical parameters were assessed at baseline and follow-up (median 200 days). Receiver operating characteristic (ROC), correlation, multiple linear and logistic regression analyses were performed to compare the predictive value of HB and AHI for BP reduction. CPAP therapy resulted in a modest, non-significant reduction in systolic BP(-2.3 mmHg ±17.7,0.1237), while diastolic BP remained unchanged. Higher AHI and HB levels were associated with higher baseline systolic BP and numerically greater BP reductions, particularly in individuals with a higher than the median HB ≥57.5%min/h or median AHI ≥34.3/h. However, neither HB nor AHI predicted a systolic BP reduction ≥5 mmHg (AUC values≈0.5), and no relevant correlations between AHI, HB and blood pressure response were observed. HB is associated with OSA severity and higher baseline BP. However, it is not superior to AHI in the prediction of a CPAP-associated reduction of BP in patients with OSA.