A mother’s weight seems to have a strong influence over her young child’s weight only in Hispanic families, while other health factors are apparently carried over between black mothers and their children, new research suggests.

The three-year study found that a Hispanic mother’s body mass index (BMI) - a measure of weight in relation to height - was important in the risk of her child becoming overweight by the age of 7. However, no such association was found among African-American and white mothers and children.

Black mothers did, however, seem to exert an influence over their children’s blood levels of insulin and cholesterol - which, like BMI, are key factors in the eventual risk of cardiovascular disease.

These ethnic differences could be due to genes, environmental factors such as diet, or a combination, the study authors report in the Archives of Pediatrics & Adolescent Medicine.

“We really can’t say for sure why these differences were found,” lead author Dr. Russell Jago, of Baylor College of Medicine in Houston, told AMN Health.

Understanding how mothers may affect their children’s risk of obesity and other heart risks, and how these effects may vary by ethnicity, could potentially help in preventing such health problems.

For example, Jago explained, interventions that involve both mothers and their children may be particularly effective for Hispanic families, while “child-specific strategies” may be more helpful in other ethnic groups.

Past research has found relationships between parents’ and children’s weights, cholesterol levels and blood pressure, but whether these relationships differ by ethnic group has been unknown. In addition, Jago and his colleagues note, previous studies have looked only at infants or children in early adolescence.

For their study, the researchers followed 133 mothers and their children for three years, collecting information on their BMI, exercise levels, blood pressure, cholesterol and insulin levels. The children were 3 to 4 years old at the study’s start, and 6 to 7 years old at the end.

The researchers found that while maternal BMI and waist circumference were associated with the same measurements in children, when the numbers were broken down by ethnicity, the mother-child relationship was strong only in Hispanic families.

Similarly, a mother’s blood levels of cholesterol and insulin influenced those of her children only in African-American families. Insulin is a hormone that regulates blood sugar, and high levels of insulin and cholesterol are part of a condition known as metabolic syndrome - a precursor to type 2 diabetes, heart disease and stroke.

Mothers’ exercise levels, Jago and his colleagues found, did not seem important in how active their children were, regardless of ethnicity. So differences in exercise do not appear to explain the ethnic disparities the study found, according to the researchers.

“Other factors,” they write, “including diet and shared genetic factors may account for these findings.”

SOURCE: Archives of Pediatrics & Adolescent Medicine, December 2004.