Genetic and environmental influences on left ventricular mass. A family study.

The relations between left ventricular mass (LVM) with age, gender, body size, and blood pressure were investigated in healthy adults and children from 149 nuclear families. LVM was strongly correlated with overall weight, especially in the children. Genetic analysis indicated that the segregation of LVM was compatible with an additive polygenic model, with a heritability estimate of 34% before adjustment for weight and 28% after adjustment for weight. Genetic and/or familial environmental factors played a strong role in the correlation of LVM and weight; they accounted for all of the correlation between the 2 traits in adults and 59% of the correlation in children. Spouses exhibited a strong correlation in their weight, which suggested that common family environment may contribute to the family correlations and to the observed heritability of the trait. LVM was strongly correlated with blood pressure before adjustment for weight, but this correlation could be attributed to nonfamilial environment rather than genetic factors. After adjustment for weight, the intertrait correlations between LVM and blood pressure were nonsignificant. Thus, adjustment for weight accounts for all common determinants of LVM and blood pressure.