Objectives: This study examines intrasibling correlations at 2 points during childhood for African American siblings with the same father, different fathers, a father present in the home, and no father present in the home.
Study design: Cardiovascular disease (CVD) risk factors were assessed in 267 pairs of African American siblings (visit 1) and in 79 of these siblings approximately 28 months later (visit 2).
Results: As a group, correlations of CVD risk factors between African American siblings with the same father were greater than those for African American siblings with different fathers in visit 1 (P <.05). However, having a father present in the home was associated with significantly lower intrasibling correlations for girth and total cholesterol in visit 2 (P <.005). Intrasibling correlations for the 4 family subgroups suggest that CVD risk factors were most similar in siblings who shared the same father but who had no father present in the home.
Conclusions: Intrasibling correlations for African American children were influenced by whether they shared the same father and whether a father was present in their home, reflecting both genetic and environmental influences. Family composition should be considered when family CVD risk factors are used to predict CVD risk in children.