The magnitude of familial associations of cardiovascular risk factor variables between parents and offspring are influenced by age: the Bogalusa Heart Study.

PURPOSE: Although parent-offspring associations of cardiovascular risk factor variables are known, the age-specific nature of this familial relationship is not clear.
METHODS: This aspect was examined in 727 unrelated children (mean age: 11.2 years) and their parents who participated in the Bogalusa Heart Study during their childhood (mean age: 11.3 years) and adulthood (mean age: 25.5 years).
RESULTS: After adjusting for covariates, the mothers' childhood-offspring correlations were consistently higher than mothers' adulthood-offspring correlations for body mass index (BMI) [r = 0.45 vs. 0.32], systolic blood pressure (SBP) [r = 0.30 vs. 0.10], diastolic blood pressure (DPB) [r = 0.22 vs. 0.13] and low-density lipoprotein cholesterol (LDLC) [r = 0.20 vs. 0.11]. In contrast, high-density lipoprotein cholesterol (HDLC) and triglycerides did not show such age-specific trends in mother-offspring correlations. Corresponding father-offspring correlations showed similar patterns, but the differences were of lesser magnitude. Multiple regression analyses using offspring's risk factor variables as dependent variables revealed that parents' childhood obesity, blood pressure and LDLC levels were better predictors of the corresponding variables in the young offspring than parents' adulthood values. Further, sex of either parents or offspring made no difference in the above findings.
CONCLUSIONS: The magnitude of the familial associations of cardiovascular risk factor variables between parents and offspring are influenced by age. Intrinsic genetic make-up, duration of exposure to environment and gene-environment interactions may play a role in this association.