Moderate to severe sleep apnea significantly raises stroke risk.
Moderate to severe cases of OSA (obstructive sleep apnea) significantly increases the risk of suffering a stroke. The study of 1,475 people found that those with moderate to sever sleep apnea at beginning of the study were 3 to 4 times more likely to have a stroke than a comparable group of patients without sleep apnea during the next four years. The study did not find any significant increase in the odds of having a stroke for people with mild sleep apnea compared with people without sleep apnea. The stroke risk we found for people with moderate to severe sleep apnea is quite significant- double the risk of other well -known risk factors for stroke, such as hypertension or diabetes. It was even found that the risk of stroke was significant even after other risk factors for stroke, such as high blood pressure and obesity, were taken into account.
The patients in the study were defined as having moderate to sever obstruction sleep apnea in their breathing stopped or slowed at least 20 times per hour of sleep. People whose breathing stopped or slowed between 5 and 20 times per hour of sleep were considered to have mild sleep apnea. One reason obstructive sleep apnea may increase stroke risk is that it has been shown to cause high blood pressure, with this, it is the most common risk factor for stroke. Another possible reason is that when a person stops breathing, the lack of oxygen kick in the body’s “fight or flight” response. Part of that reaction is to make the blood more clottable, and blood clots in the brain can cause a stroke.
This study provides yet another reason why it’s so important to treat sleep apnea with all caution as possible. It also raises the question of weather people with sleep apnea should be put on aspirin therapy or given other anti-clotting drugs/medications, which is what is done for other people with stroke risk, but this is an issue that needs further research.