What is the effect of Obstructive Sleep Apnea (OSA) on blood pressure?

From the Guidelines

Obstructive sleep apnea (OSA) significantly increases blood pressure and contributes to hypertension, and treatment with continuous positive airway pressure (CPAP) can reduce blood pressure by approximately 2-10 mmHg, with greater effects seen in patients with resistant hypertension or more severe OSA. When OSA occurs, repeated episodes of upper airway collapse during sleep lead to intermittent hypoxia, increased sympathetic nervous system activity, and sleep fragmentation. These physiological changes trigger a cascade of effects including systemic inflammation, oxidative stress, and endothelial dysfunction that directly elevate blood pressure. Many patients with OSA experience not only sustained daytime hypertension but also a loss of the normal nocturnal blood pressure dipping pattern, creating a "non-dipper" profile that increases cardiovascular risk. The relationship is bidirectional, with approximately 50% of patients with hypertension having some degree of OSA, as noted in a study published in the Journal of Clinical Sleep Medicine in 2017 1.

Key Findings

• OSA is associated with an increase in all-cause mortality, with a meta-analysis of over 25,000 individuals showing relative increased risks of 1.79 for cardiovascular disease, 2.15 for fatal and nonfatal stroke, and 1.92 for death from all causes 1.
• Treatment with CPAP can reduce fatal and nonfatal cardiac events, and reduce recurrence of atrial fibrillation, as demonstrated in a study published in the Journal of Clinical Sleep Medicine in 2019 2.
• Weight loss of 5-10% body weight can also significantly improve both OSA severity and blood pressure control.
• Patients with hypertension, particularly resistant hypertension, should be screened for OSA, as treating the underlying sleep disorder is an essential component of comprehensive blood pressure management, as recommended in the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 3.

Recommendations

• CPAP should be used at least 4 hours nightly, combined with standard antihypertensive medications as needed, to optimize blood pressure management in OSA patients.
• Patients with OSA and comorbid hypertension should be treated with CPAP, as the benefits of PAP therapy compared to no PAP therapy likely outweigh the potential harms and burdens, as suggested in a study published in the Journal of Clinical Sleep Medicine in 2019 2.
• Non-sleepy patients with OSA may have a more nuanced view of whether to pursue treatment of OSA, particularly given the efficacy of standard antihypertensive treatments, and should have a balanced discussion with their clinician about the current state of the evidence about CV risk reduction with PAP therapy for OSA.

From the Research

Effect of Obstructive Sleep Apnea on Blood Pressure

• Obstructive sleep apnea (OSA) plays a significant role in the development of hypertension, with current treatments such as continuous positive airway pressure (CPAP) being effective at lowering blood pressure, although only providing a modest reduction 4.
• The use of CPAP in addition to antihypertensive medication has been shown to have a positive effect on blood pressure control, particularly in patients with resistant hypertension 5, 6.
• Different classes of antihypertensive medications, such as beta blockers, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers, have been found to be effective in controlling blood pressure in patients with OSA 4, 7, 8.
• A network meta-analysis found that mineralocorticoid receptor antagonists and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers were significantly associated with blood pressure reduction in patients with OSA, while CPAP demonstrated modest blood pressure lowering 7.
• The mechanism of OSA-related hypertension is thought to involve sympathetic activity due to intermittent hypoxia and/or fragmented sleep, and antihypertensive medications targeting sympathetic pathways or the renin-angiotensin-aldosterone system may be effective in management 8.

Treatment Options for OSA-Related Hypertension

• CPAP therapy is effective at lowering blood pressure, but the magnitude of the decrease is relatively modest, and patients often require additional antihypertensive medications to achieve optimal blood pressure control 4, 8, 6.
• Beta blockers and renin-angiotensin system inhibitors may be effective in the management of OSA-related hypertension, but current evidence is limited 4, 8.
• Other potential treatment options for OSA-related hypertension include angiotensin receptor-neprilysin inhibitors, sodium-glucose cotransporter 2 inhibitors, and glucose-dependent insulinotropic polypeptide receptor/glucagon-like peptide-1 receptor agonists 8.