Sleep Apnea Patients With Insomnia See Larger BP Reduction With CPAP, Suggests Study
China: Researchers have found in a new study that patients with comorbid insomnia and obstructive sleep apnea (COMISA) experienced significantly greater reductions in 24-hour systolic blood pressure after 4 weeks of continuous positive airway pressure (CPAP) therapy compared with patients who had obstructive sleep apnea alone. Baseline insomnia independently predicted a clinically meaningful improvement in blood pressure, suggesting that patients with COMISA may derive particular cardiovascular benefits from CPAP treatment.
The findings are from a prospective cohort study published in Chest Journal by Shuang Li, MD, Department of Respiratory and Critical Medicine, Beijing Anzhen Hospital, Capital Medical University, Beijing, China, and colleagues.
Obstructive sleep apnea is frequently accompanied by insomnia, a combination known as COMISA. Both conditions have been associated with difficulties in controlling blood pressure, potentially increasing cardiovascular risk. However, whether the presence of insomnia influences the blood pressure-lowering response to CPAP therapy has remained unclear.
To investigate this, researchers conducted a prospective cohort study involving 71 adults with OSA and elevated blood pressure. All participants received 4 weeks of auto-CPAP therapy. Based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria, 22 participants were classified as having COMISA, while 49 had OSA without comorbid insomnia.
The primary outcome was a clinically meaningful reduction in 24-hour systolic blood pressure (SBP), defined as a decrease of at least 5 mm Hg. Researchers also evaluated changes in 24-hour, daytime, and nighttime systolic and diastolic blood pressure.
The study led to the following findings:
- After 4 weeks of CPAP therapy, 24-hour systolic blood pressure (SBP) fell significantly more in the COMISA group than in the OSA-alone group (−6.0 ± 8.2 mm Hg vs −0.3 ± 6.5 mm Hg).
- Patients with COMISA also showed greater reductions in daytime and nocturnal SBP following CPAP therapy.
- Baseline insomnia independently predicted a clinically meaningful reduction of at least 5 mm Hg in 24-hour SBP, with an adjusted odds ratio of 5.62.
- However, after Bonferroni adjustment for multiple comparisons, the associations between insomnia and reductions in 24-hour, daytime, and nocturnal SBP were no longer statistically significant.
The researchers concluded that COMISA may represent a distinct clinical phenotype in which patients experience a stronger blood pressure response to CPAP, particularly in terms of achieving a clinically relevant reduction in 24-hour SBP. The findings also suggest that recognizing and managing both insomnia and OSA could potentially help optimize cardiovascular outcomes.
The authors emphasized that improving CPAP adherence remains particularly important in patients with COMISA, as sustained use of therapy may be essential for maximizing its potential cardiovascular benefits.
Reference:
Li, S., Jiao, Y., Zhou, Z., Zhang, H., Lou, L., Wang, C., Xie, J., & Wu, H. (2026). Comorbid Insomnia Is Associated With Enhanced BP Reduction With CPAP Therapy in Patients With OSA: A Prospective Cohort Study. CHEST. https://doi.org/10.1016/j.chest.2026.07.5226
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