"Studies have shown how stroke causes memory complaints," said Arfan Ikram, M.D., associate professor of neuroepidemiology at Erasmus University Rotterdam in The Netherlands. "Given the shared underlying vascular pathology, we posed the reverse question: 'Do memory complaints indicate an increased risk of strokes?'"
As part of the Rotterdam Study (1990-93 and 2000-01), 9,152 participants 55 or older completed a subjective memory complaints questionnaire and took the Mini-Mental State Examination (MMSE).
By 2012, 1,134 strokes occurred: 663 were ischemic, 99 hemorrhagic and 372 unspecified.
Subjective memory complaints was independently associated with a higher risk of stroke, but a higher MMSE score wasn't.
Furthermore, those with memory complaints had a 39 percent higher risk of stroke if they also had a higher level of education. The finding is comparable to the association between subjective memory complaints and Alzheimer's disease among highly educated people.
"Given the role of education in revealing subjective memory complaints, we investigated the same association but in three separate groups: low education, medium education and high education," Ikram said. "We found that the association of memory complaints with stroke was strongest among people with the highest education. If in future research we can confirm this, then I would like to assess whether people who complain about changes in their memory should be considered primary targets for further risk assessment and prevention of stroke."
Researchers categorized level of education into three groups: low education - primary education only; intermediate education - primary education plus some higher education, lower vocational education, intermediate vocational education, or general secondary education; and high education - higher vocational education or university training.
The study results apply evenly to men and women. With more than 95 percent of study participants being Caucasians living in Rotterdam, future studies should include more racially diverse groups, Ikram said.