The results of a study published in the journal Stroke suggest that patients who have suffered a stroke have twice the risk of dementia compared with healthy subjects.

“Identification of risk factors for dementia after stroke is best performed in comparison with stroke-free controls, because older subjects at high risk for stroke also have a substantial risk of dementia in the absence of stroke,” Dr. Philip A. Wolf and colleagues from Boston University School of Medicine, write.

Dr. Wolf’s group prospectively examined these risk factors in members of the community-based Framingham Study. They compared 212 dementia-free subjects in January 1982 who had a first stroke after that date with 1,060 healthy control subjects.

The researchers calculated 10-year risk of dementia and estimated the risk within subgroups defined by various risk factors.

Over 10 years of follow-up, 41 (19.3 percent) stroke patients and 117 (11.0 percent) controls developed dementia. The risk was not reduced by adjusting the data for other possible contributing factors, such as age and sex.

Subjects younger than age 80 years had a higher risk of dementia (2.6-times the risk). The risk was also higher in those who had completed high school (2.4-times) compared with those who did not graduate (1.7-times).

In addition, subjects with a specific genetic pattern of apolipoprotein E, a blood protein associated cardiovascular disease, had more than 3-times the risk.

These findings reinforce the importance of stroke prevention measures, not only to reduce death, illness and disability directly attributable to the stroke, but to also reduce the risk of dementia, Dr. Wolf and colleagues conclude.

SOURCE: Stroke, June 2004.