July 8, 2005

Child’s birthweight tied to parents’ heart risks

By Amy Norton

NEW YORK (Reuters Health) - A new study has found that the
parents of children born at a lower weight may have an
increased risk of dying from heart disease or stroke --
suggesting that common genetic factors may underlie both
birthweight and cardiovascular disease.

A number of studies have found evidence that people born at
a low weight have a higher risk of diabetes and cardiovascular
disease as adults. One hypothesis is that factors that affect
fetal development -- such as a mother's nutrition -- may help
"program" future disease risk.

But another possibility is that certain genes passed down
from parents contribute to both poorer fetal growth and later
disease risk. If fathers, in particular, show a higher
cardiovascular disease risk if their children are born at a low
weight, then that would be some evidence of a common genetic

The new study, published in the journal Epidemiology, found
such evidence.

Looking at data on more than 780,000 children born in
Sweden between 1973 and 1980, researchers found that as
birthweight climbed, the risk of a parent dying from
cardiovascular disease declined.

The pattern was the same for mothers and fathers, and
factors such as smoking did not fully account for the
connection between birthweight and parents' disease risk. In
addition, the relationship between birthweight and
cardiovascular disease was strongest among parents who died at
a young age; early cardiovascular disease tends to have a
strong genetic influence.

It seems likely that genes help explain research findings
that have linked a person's own birthweight to the risk of
adulthood cardiovascular disease, study co-author Dr. Finn
Rasmussen of the Karolinska Institute in Stockholm told Reuters

However, he added, environmental factors during fetal
development are also important. Nutrition in the womb and
growth during infancy have been implicated in cardiovascular
illness and other diseases, the researcher noted.

It's unclear exactly which genes could underlie both
birthweight and cardiovascular disease. But, Rasmussen and his
colleagues write, their findings "support the search for such

In addition, they note, the study highlights the fact that
a child's birth characteristics can serve as an indicator of
not only a mother's health, but also a father's.

SOURCE: Epidemiology, July 2005.