Familial aggregation of stroke. The Framingham Study

Area of Science:

• Cardiovascular epidemiology
• Genetics of stroke
• Public health

Background:

• Family history is commonly believed to be a stroke risk factor.
• Published data on familial aggregation of stroke are conflicting.
• The Framingham Study provides a unique dataset for investigating multi-generational stroke risk.

Purpose of the Study:

• To examine the patterns of familial aggregation of stroke across three generations.
• To determine if parental or sibling history of stroke influences stroke risk.
• To assess the association between parental history of coronary heart disease and stroke risk.

Main Methods:

• Utilized Cox proportional hazards analyses, adjusting for known stroke risk factors.
• Analyzed three groups: original Framingham cohort (parental death reports), Offspring Study (verified parental stroke), and sibships within the original cohort.
• Examined associations between parental stroke, sibling stroke, and parental coronary heart disease with stroke events.

Main Results:

• No association found between original cohort members' stroke and reported parental stroke death.
• Verified parental stroke history showed an increased stroke risk in the Offspring Study (paternal RR=2.4, maternal RR=1.4).
• Parental history of coronary heart disease strongly associated with stroke in Offspring (RR=3.33); sibling history showed no significant stroke association.

Conclusions:

• Parental history of stroke appears to be a significant risk factor for stroke.
• Further investigation is warranted as more stroke events accrue in the Framingham Offspring Study cohort.
• These findings contribute to understanding the genetic and familial components of stroke risk.