Intrafamilial relations of cardiovascular disease risk factors in African-Americans: longitudinal results from DC SCAN

Abstract

Background: Few studies have examined intrafamilial patterns of cardiovascular disease (CVD) risk factors in African-American families or identified potential influences on these patterns. This study examines the effects of age and sex of child on correlations between siblings during childhood as well as between mothers and their offspring in African-American families at two points in time.

Methods: CVD risk factors were assessed in a sample of 267 pairs of African-American siblings and their mothers. One hundred nine of these families were selected for a second assessment of CVD risk factors approximately 28 months later.

Results: Older siblings had significantly greater correlations than younger siblings with mothers' low-density lipoproteins (r = 0.61 versus r = 0.43 for older and younger siblings, respectively), apolipoprotein A-I (r = 0. 46 versus r = 0.16), and lipoprotein (a) (r = 0.71 versus r = 0.34). Correlations between female siblings were significantly higher than between male siblings for total cholesterol (r = 0.74 versus r = 0. 18 for female versus male siblings), triglycerides (r = 0.56 versus r = 0.05), and apolipoprotein B (r = 0.72 versus r = 0.31); they were also higher between female siblings than between mixed-sex siblings for measures of adiposity (r = 0.46 versus r = 0.19) and total cholesterol (r = 0.74 versus r = 0.27).

Conclusions: Significant intrafamilial correlations for African-American children were influenced by both age and sex of siblings, reflecting potential genetic and environmental influences. Assessing family patterns of CVD risk factors in high-risk populations may assist in the early identification of children who can benefit most from intervention.