The effect of continuous positive airway pressure on nocturnal blood pressure among obstructive sleep apnea-hypopnea syndrome patients.

Purpose: Few articles focus on the effect of CPAP on the nocturnal blood pressure in OSA patients. This study aims to evaluate the effects of continuous positive airway pressure (CPAP) therapy on nocturnal blood pressure in individuals with obstructive sleep apnea-hypopnea syndrome (OSAHS), which fills the research gap. Additionally, differences in nocturnal blood pressure measurements before and after CPAP therapy were analyzed across varying disease severities.

Methods: A total of 80 individuals with newly diagnosed OSAHS who sought care at the Sleep Respiratory Disease Diagnosis and Treatment Center at West China Fourth Hospital of Sichuan University between December 2022 and June 2023 were included in this study. All participants completed a single night of CPAP therapy, administered from 10:00 PM on day 1 to 6:00 AM on day 2, during which nocturnal blood pressure measurements were assessed using pulse transit time.

Results: Following CPAP therapy, significant reductions were observed in the mean nocturnal diastolic blood pressure (nDBP) [(78.40 ± 13.06) vs. (74.03 ± 9.90) mmHg] and the nocturnal blood pressure fluctuation index (NBPFI) [(21.38 ± 19.95) vs. (5.81 ± 5.40) n/h] (p < 0.05). However, no significant difference was noted in the mean nocturnal systolic blood pressure (p > 0.05). Subgroup analysis based on disease severity: The reductions in nDBP [(6.16 ± 11.89) vs. (-0.32 ± 12.43) mmHg, p < 0.05] and nocturnal blood pressure fluctuation [(20.48 ± 19.05) vs. (2.59 ± 4.44) n/h, p < 0.05] were significantly greater in the severe group compared to the mild-to-moderate group.

Conclusion: The findings suggested that CPAP therapy could potentially contribute to reductions in nDBP and the NBPFI in individuals with OSAHS, with more noticeable effects in patients with severe OSAHS.