Children with a strong family history of heart attack or type 2 diabetes may already have higher cholesterol levels than other kids without those family legacies, according to a new study from the Netherlands.

"Myocardial infarction in the family was related to children's cholesterol whereas diabetes in the family was related to children's waist circumference, cholesterol and HbA1c (a measure of average blood sugar levels), which are typical markers for those diseases," said lead author Nina E. Berentzen of the National Institute for Public Health and the Environment in Bilthoven and University Medical Center Utrecht.

"Importantly, both family histories were independently associated with higher cholesterol levels in children, indicating that these disease histories may contribute to cardiometabolic risks via separate routes," Berentzen told Reuters Health by email.

The researchers used data on more than 1,300 children in The Netherlands, all 12 years old. Their parents reported their own and their parents' history of cardiovascular disease, including heart attack and stroke, as well as type 2 diabetes.

Children with relatives with these conditions, especially those with family history of early onset of these diseases, were classified as having a strong family history.

About 400 of the children, or 29 percent of the group, had a strong family history of heart attack, stroke or diabetes, with heart attack and diabetes being most common. Most had a strong family history of one disease only.

Kids also had their waist circumference, cholesterol, blood pressure and fasting blood sugar recorded.

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Kids with a strong family history of one of the diseases were more often overweight and had parents with lower education and higher body mass index than those without a family history of disease.

Having a strong family history of disease was also tied to having higher total cholesterol and lower levels of so-called "good cholesterol" relative to the total cholesterol measurement, according to the results in Diabetologia.

Children with a strong family history of type 2 diabetes had an average waist circumference 2.25 centimeters (about 1 inch) larger than peers without that family history.

A family history of stroke alone was not associated with any differences among the children, however.

"Cardiometabolic markers such as blood pressure, cholesterol and waist circumference are considered important risk factors for cardiovascular disease in adulthood," Berentzen said. "It has been estimated that they explain about half of the variation in occurrence of coronary heart disease, together with other traditional risk factors such as smoking, diet and physical inactivity."

Risk begins to accumulate in childhood and adolescence when lifestyle habits are established, she said.

The cardiometabolic markers in this study were not clinically significant for the kids, and would take years to develop into overt heart disease, she said.

Childhood risk factors strongly predict adult risk factors, said Dr. Markus Juonala of the Turku University Hospital Department of Internal Medicine in Finland, who was not part of the new study.

But symptomatic heart disease usually emerges after age 50, Juonala told Reuters Health by email.

"It is well known that adults with high levels of cardiometabolic markers have increased risks for cardiovascular disease (e.g. heart attack and stroke) and diabetes," Berentzen said. "Therefore, children with unfavorable levels of cardiometabolic markers may become adults with increased risks for those diseases, which may be difficult to reduce once the risks have established," she said.

"Healthy lifestyle habits, such as a healthy diet, physical activity and less inactivity are important to maintain a healthy weight in order to keep cholesterol levels within the healthy range, and to reduce the risk of fatty buildup in the arteries," she said. "By making healthy choices for themselves and their children, parents could lower risks of future disease for the entire family."