Multiplex sibling history of coronary heart disease is a strong risk factor for coronary heart disease

Area of Science:

• Cardiovascular Epidemiology
• Genetics of Heart Disease
• Public Health

Background:

• Familial aggregation of coronary heart disease (CHD) is recognized, but risks in families with multiple affected siblings require further investigation.
• Understanding these risks is crucial for identifying high-risk individuals and families.

Purpose of the Study:

• To quantify the familial risk of hospitalization or death due to coronary heart disease (CHD) in individuals with multiple affected siblings.
• To determine if the risk of CHD increases with the number of affected siblings in a family.

Main Methods:

• A nationwide cohort study utilizing Swedish Multigeneration Register data linked to hospitalization and death records (1964-2008).
• Standardized incidence ratios (SIRs) were calculated for siblings and spouses of individuals hospitalized or deceased due to CHD.
• Comparison groups included individuals with unaffected siblings.

Main Results:

• Siblings of affected individuals had a 1.82-fold increased risk of CHD hospitalization and a 1.60-fold increased risk of CHD death.
• The risk of CHD hospitalization and death significantly increased with two or three affected siblings, with SIRs ranging from 6.61 to 7.88.
• Spouses showed minimal familial risk (SIR = 1.05).

Conclusions:

• A family history of multiple affected siblings is a significant risk factor for coronary heart disease (CHD).
• CHD risk is not a simple binary trait but demonstrates a dose-response relationship with the number of affected siblings.
• These findings highlight the importance of detailed family history in assessing individual CHD risk.