July 08, 2019
By Will Boggs MD
NEW YORK (Reuters Health) - All infection types appear to be associated with an increased risk of acute ischemic stroke, according to a database study.
"(I was surprised) that we found associations such that a broad range of infections were associated with both ischemic and hemorrhagic stroke," Dr. Mandip S. Dhamoon from Icahn School of Medicine at Mount Sinai, New York City told Reuters Health by email.
Acute infections have been investigated as possible triggers of stroke, but findings have been inconsistent.
Dr. Dhamoon's team used the New York State Inpatient and Emergency Department Databases from 2006 to 2013 to examine the possible associations between infections in different body systems and the risk of ischemic stroke, subarachnoid hemorrhage (SAH), and intracerebral hemorrhage (ICH).
Every infection type (skin, urinary tract, abdominal, respiratory, and septicemia) was associated with significantly increased odds of acute ischemic stroke, according to the June 27th Stroke online report.
The greatest association was for urinary tract infection (UTI), which was associated with 5.32-fold increased odds of ischemic stroke within 7 days of infection.
As with UTI, the magnitude of risk decreased for all infection types with longer intervals before the ischemic stroke.
There were also significant associations between skin, urinary tract, and respiratory infections and septicemia and ICH, although the odds were generally lower than for acute ischemic stroke.
There were few cases of SAH following infections, and only respiratory infection showed significantly increased odds.
"Possible candidate mechanisms are inflammatory states, changes in coagulation profiles, and immune changes," Dr. Dhamoon said.
"Further research is needed to clarify which patients with infection are more prone to developing stroke, both ischemic and hemorrhagic," he said.
Dr. Amelia K. Boehme from Columbia University in New York City, who recently evaluated risk factors for stroke in patients with sepsis and bloodstream infections, told Reuters Health by email, "These results are consistent with other studies that have shown infections trigger stroke, even infections as common as a UTI."
"One issue that occurs with this work, and with the prior studies, is we have been using large administrative databases with data from emergency departments (EDs) and inpatient admissions," she said. "This could indicate that only infections that are severe enough to seek care in an ED, or those that develop during a prior hospitalization are associated with an increased risk of stroke."
"There is significant evidence that the more severe the infection, the higher the risk of stroke," Dr. Boehme said. "More work needs to be done to see if the relationship remains in populations with infections that do not result from an inpatient hospitalization, or that necessitate a visit to the ED."
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