A recent study funded by the American Heart Association found a huge correlation between infections and an increased risk of stroke. Skin, abdominal, blood, and respiratory infections all increased the risk of a stroke, but urinary tract infections were at the top of the list.
The study focused on a cross-over analysis for hospitalizations in the New York State Inpatient and Emergency Department Databases from 2006 to 2013 due to strokes (acute ischemic strokes and intracerebral and subarachnoid hemorrhages). Any type of infection increased the risk of stroke or hemorrhage, but they found that having a urinary tract infection was associated with an increased risk of acute ischemic stroke.
The type of stroke we commonly think of that is caused by a clot in the brain which obstructs blood flow to the brain is an ischemic stroke. Another type of stroke is hemorrhagic stroke: when a blood vessel ruptures (hemorrhages) and also interrupts blood flow to the brain. An intracerebral hemorrhage is caused by a hemorrhage within the brain tissue, and a subarachnoid hemorrhage occurs when there is bleeding between your brain and the membrane which surrounds it (the subarachnoid space). When the brain is not receiving adequate blood, it cannot receive the oxygen that the blood carries and causes brain cells to die within minutes.
Following the risk of acute ischemic stroke, urinary tract infections had a lower risk associated with intracerebral hemorrhage. Subarachnoid hemorrhage was linked to respiratory infection.
The study published on June 27, 2019 did not elaborate on why urinary tract infections increased the risk of an ischemic stroke, but I believe it will prompt more studies to focus on this correlation. I would be interested in knowing if these were urinary tract infections that had already been started on antibiotic treatment or if they had been left untreated prior to the stroke.
Strokes are the #5 cause of death and disability in the United States, and almost 50% of those who have a hemorrhagic stroke will die in the following four weeks. How can we lower our risk of stroke?
High blood pressure, heart disease, family history and ethnicity, age, gender, being overweight, smoking, and some medications (such as blood thinners, hormone replacement therapy for menopause, and birth control containing estrogen) can all increase your risk of stroke. Maintaining a healthy blood pressure, working closely with your doctor on any conditions you have, and being sure to mention your family history is one of the best ways to look out for strokes.
- Sebastian, Solly, et al. “Infection as a Stroke Trigger.” Stroke, vol. 50, no. 22, 27 June 2019, pp. 2216–2218., doi:https://doi.org/10.1161/STROKEAHA.119.025872.