Neck arteries of obese children as young as 10 resembled those of a typical 45-year-old, a new study has found.

The research is more evidence that the process of artery disease can begin early in life, increasing the risk of premature heart disease in adulthood.

"These findings confirm some of our big picture concerns about childhood obesity," said Aaron Carrel, an associate professor of paediatrics at the University of Wisconsin school of medicine and public health. "It is a very direct link with disease."

Carrel, who was not a part of the research, said artery disease in obese children was something that doctors had long suspected, but the level of disease found in the study was higher than anticipated. UW doctors also have been finding abnormally high levels of cholesterol in obese kids ages 5 to 18, Carrel said.

The study involved 70 boys and girls children ages 10 to 16, with an average age of 13. Forty of the children were obese and 30 were not but had genetically high cholesterol levels.

Doctors used an ultrasound test to determine the thickness of the inner wall of their carotid arteries. In adults, such tests are considered a good surrogate for the amount of fatty plaque build-up in the arteries of the heart. The average thickness for the children in the study was equivalent to that of a 45-year-old.

The study was presented yesterday at the American Heart Association meeting. It found the most carotid artery thickness in the obese kids who also had high systolic blood pressure (the upper reading). Kids who had high levels of triglycerides, a type of unhealthy fat in the blood, were the most likely to have so-called advanced vascular age.

On average, the children also had total cholesterol of 224 (less than 170 is acceptable), LDL cholesterol (the bad kind) of 150 (less than 110 is acceptable), and triglycerides of 152 (less than 150 is acceptable).

Lead author Geetha Raghuveer said more work needs to be done to see whether the plaque build-up can be reduced if the children lose weight, exercise or are put on cholesterol-lowering drugs. Because they are young, their plaque may not have calcified and hardened, she said.

"I'm very hopeful that this is something that is reversible," said Raghuveer, an associate professor of paediatrics at the University of Missouri-Kansas City school of medicine. "I hope I haven't scared everybody. This is a wake-up call."

She said exposure to secondhand smoke also may be contributing to the problem.

The approach used in the study may help identify children who need cholesterol-lowering statin drugs or prescription fish oil, which can lower triglycerides, said Ramin Alemzadeh, a professor of paediatrics at the Medical College of Wisconsin and director of the diabetes program at Children's Hospital of Wisconsin in Wauwatosa.

"We need to identify kids who are at risk," he said. "Do we start [statins] at age 8 or 10?"

Before carotid ultrasound can become a widespread tool, national reference data for children will have to be developed, he said.

He said he was especially interested in the finding that high triglycerides were associated with abnormal carotid readings. He said prescription fish oil often can substantially lower triglycerides in children.

In a separate study, researchers from Australia found that overweight and obese children were more likely to have an oversized left atrium, one of the four chambers of the heart.
In adults, a larger left atrium is associated with an increased risk of heart attack, stroke and an irregular heartbeat known as atrial fibrillation.

The study, involving 991 kids ages 5 to 15, was presented by researchers at Royal Prince Alfred hospital in Sydney.