Obstructive sleep apnea (OSA) has been shown to increase the risk of cardiovascular disease. Type B natriuretic peptide (BNP) is a hormone secreted by the heart when it is stressed. There is conflicting data about the association of OSA and elevated BNP levels, especially in asymptomatic patients, and among women. This study analyzed the association between OSA and BNP in a community-based sample of women. All participants had overnight sleep studies and blood work done the next morning.
The results showed a dose-response relationship between increasing OSA severity and elevated BNP levels, even after adjusting for confounding variables like age, body-mass index, blood pressure, and kidney function. The study authors theorize that during an OSA event, the chest cavity has a reduced pressure, and more blood enters that region. More blood also gets to the heart, stretching the walls a little more. This stresses the heart and BNP is released. Also, OSA can cause low oxygen levels, and this may stress the heart, which would then release more BNP. The authors conclude that BNP could serve as a marker in OSA patients who may be at increased risk for cardiovascular disease.