Maybe you already know that high blood pressure, smoking and age are key risk factors for an abdominal aortic aneurysm, but sleep apnea is now being fingered as a player in this potentially fatal condition.
A new line of research from the University of Missouri School of Medicine and NextGen Precision Health suggests it may even play a role in the development of abdominal aortic aneurysms.
These aneurysms happen when the abdominal section of the aorta — the body’s main artery — begins to swell and weaken.
If it ruptures, it can lead to severe, life-threatening internal bleeding.
Sleep apnea, on the other hand, involves repeated pauses in breathing during sleep, which when untreated, will reduce oxygen levels and strain the cardiovascular system over time.
Untreated sleep apnea can cause high blood pressure, which as mentioned is a major risk factor for the development of a bulging area of the abdominal aorta.
Scientists at MU looked into whether obstructive sleep apnea (OSA) might be connected to a higher risk of abdominal aortic aneurysms, based on earlier studies showing a higher prevalence of aneurysms in people with sleep apnea.
They used mouse models to study how oxygen deprivation patterns similar to sleep apnea might affect the aorta.
The focus was on intermittent hypoxia, which is the repeated drop in oxygen levels that happens when breathing repeatedly stops and starts during sleep.
What does intermittent hypoxia do to the body?
In people, this can lead to a variety of problems including daytime drowsiness, brain fog, difficulty concentrating, irritability and moodiness, falling asleep while driving and high blood pressure that doesn’t respond to dietary changes or even medication.
The researchers found that intermittent hypoxia made mice more vulnerable to developing abdominal aortic aneurysms.
However, it did not directly cause aneurysms on its own. Instead, it seemed to increase risk when combined with other health issues, such as metabolic conditions like obesity.
The paper says that intermittent oxygen loss alone isn’t enough to trigger aneurysms.
But in people with sleep apnea and other risk factors, it may contribute to weakening the aortic structure over time.
How Oxygen Loss Can Weaken the Aorta
The proposed mechanism involves enzymes called MMPs, which become more active when oxygen levels repeatedly drop.
These enzymes help break down the extracellular matrix — a structural support network that helps maintain tissue strength.
When that support system is degraded, the aorta may become more fragile.
Over time, this weakening could make it easier for an aneurysm to form or expand.
Why Abdominal Aortic Aneurysms Are Hard to Detect
One of the challenges with abdominal aortic aneurysms is that they often develop silently.
Most people don’t notice symptoms until the aneurysm becomes large or begins to rupture.
When symptoms do appear, they may include back or abdominal pain, but the most dangerous cases occur when the aneurysm bursts suddenly, requiring emergency surgery to repair this blood vessel.
While the study adds to evidence linking sleep apnea with cardiovascular risk, it’s important to note that the findings are based on animal research.
That means they show a biological mechanism and increased susceptibility in mice, but not direct proof that sleep apnea causes aneurysms in humans.
Still, the research suggests that repeated oxygen deprivation during sleep may be one of several factors that contributes to weakening blood vessels over time, particularly in people with other underlying health conditions.
