Feed

Objective: To investigate the effect of continuous positive airway pressure (CPAP) therapy on blood pressure and vascular endothelial function in patients with hypertension and moderate-to-severe obstructive sleep apnea (OSA). Methods: This was a retrospective study. Patients diagnosed with hypertension and moderate-to-severe OSA in the Department of Hypertension, Tianjin Kanghui Hospital, from October 2023 to December 2024 were enrolled. Patients were divided into the observation group (received standard CPAP therapy ≥4 hours per night and ≥5 nights per week) and the control group (did not receive CPAP therapy). Both groups received standard antihypertensive medication and were observed continuously for 24 weeks. Vascular endothelial function was assessed by flow-mediated dilation (FMD) of the brachial artery, and blood pressure fluctuations were evaluated by ambulatory blood pressure monitoring. Spearman rank correlation analysis was used to evaluate the correlation between changes in endothelial function and changes in blood pressure parameters. Antihypertensive medication load was assessed using the defined daily dose of antihypertensive drugs. Results: A total of 109 patients with hypertension and moderate-to-severe OSA were enrolled, with an age of (47.13±11.21) years, including 15 females (14%). There were 54 patients in the observation group and 55 in the control group. After 24 weeks of treatment, FMD was higher in the observation group than in the control group ((7.15±1.15)% vs. (4.08±1.46)%, P0.001). Ambulatory blood pressure monitoring showed that the mean 24-hour systolic blood pressure ((120.96±5.27) mmHg vs. (124.71±3.15) mmHg) and mean 24-hour diastolic blood pressure ((77.36±6.99) mmHg vs. (81.60±3.67) mmHg) were lower in the observation group than in the control group (both P0.05). Specifically, the mean daytime systolic blood pressure ((123.86±5.83) mmHg vs. (126.73±4.65) mmHg), mean daytime diastolic blood pressure ((80.12±7.16) mmHg vs. (82.75±4.61) mmHg), mean nighttime systolic blood pressure ((116.40±5.37) mmHg vs. (123.12±5.99) mmHg), and mean nighttime diastolic blood pressure ((72.57±7.54) mmHg vs. (80.29±5.67) mmHg) were all lower in the observation group than control group (all P0.05). The nighttime systolic blood pressure dipping ratio ((5.88±2.73)% vs. (3.13±4.45)%) and nighttime diastolic blood pressure dipping ratio ((9.37±5.65)% vs. (2.89±5.92)%) were higher in the observation group than the control group (both P0.05). In addition, the defined daily dose of antihypertensive drugs was lower in the observation group than in the control group ((1.60±0.86) vs. (2.26±0.87), P0.001]. Spearman rank correlation analysis showed that changes in FMD were negatively correlated with the reduction in mean nighttime diastolic blood pressure only in the observation group (r=-0.441, P=0.001). Conclusion: CPAP therapy is associated with improved vascular endothelial function, reduced blood pressure and reversal of non-dipper blood pressure rhythm in hypertensive patients with moderate to severe OSA.