A patient whose brother or sister has had a stroke could be up to 94% more likely to suffer the same fate than a person with stroke-free siblings, caution researchers in Sweden (Circ Cardiovasc Genet. 2012;5:226-233).
The study identified 30,735 stroke-free siblings of persons with incident ischemic stroke recorded between 1987 and 2007. (The stroke-free siblings were referred to as “exposed” participants in the study.) An additional 152,391 stroke-free persons with stroke-free siblings were also included in the analysis; these individuals were known as “unexposed” participants.
Compared with unexposed siblings, exposed siblings were: 94% more likely to have an ischemic stroke at age 55 years or younger if their sibling’s stroke occurred at age 55 years or younger; 64% more likely to have an ischemic stroke if they shared two parents with the affected sibling (the sibling who had a stroke); 61% more likely to have an ischemic stroke whether they shared one or two parents with their affected sibling; and 41% more likely to have an ischemic stroke if they shared only one parent with the affected sibling.
Stroke risk was not influenced by the gender of either sibling.
Genetics might not be the only factor at play: Similar—and modifiable—lifestyle habits within families can also affect a person’s stroke risk, the researchers said.