These findings challenge the widely held view that adverse social circumstances in childhood lead to an increased risk of coronary heart disease in later life.
The study involved 3,189 randomly selected schoolchildren from Denmark (one of the richest countries in Europe), and two poorer countries, Estonia and Portugal. Insulin resistance (a pre-cursor of heart disease) was measured for each child.
Among Danish children, those with the most educated and highest earning parents were the least insulin resistant. But the opposite was true for children from Estonia and Portugal - those from the most educated and highest earning parents were the most insulin resistant.
The higher levels of insulin resistance among children of better educated parents in Estonia and Portugal may be the result of adoption of Western lifestyles, suggest the authors.
These results are an important reminder that socioeconomic inequalities are dynamic and vary over time and between countries, they conclude.
In an accompanying commentary, researchers question whether consumption of Western style "junk" food is creating the pattern of high insulin resistance among children of highly educated parents. Instead they suggest that anomalies like these help point towards gaps in our understanding and warn against too simplistic a view of health inequalities.