Hundreds of previous studies have shown that obesity comes with a number of risks, such as heart disease or metabolic problems. What worries researchers is the fact that the earlier obesity sets in, the sooner the health problems appear. This seems to be the subject of a new study presented Tuesday at the American Heart Association’s Scientific Sessions 2008 in New Orleans.

 The study found that the arteries of many obese children and teenagers are as thick and stiff as those of 45-year-olds, a sign that such children could have severe cardiovascular disease at a much younger age than their parents unless something is done about it.

“Its possible that they will have heart disease in their 20s and 30s. There’s a saying that ‘you’re as old as your arteries,’ meaning that the state of your arteries is more important than your actual age in the evolution of heart disease and stroke. We found that the state of the arteries of these children is more typical of a 45-year-old than of someone their own age,” Said Dr. Geetha Raghuveer of the University of Missouri at Kansas City, who led the study. Dr. Raghuveer runs a preventive cardiology clinic for children who have high cholesterol, obesity and a family history of cardiac deaths.

According to a federal report in May, 32 percent of US children were considered at risk for obesity, 16 percent were obese and 11 percent were extremely obese in 2006. The rates were basically the same as those in 2003-2004.

For the study, Dr. Raghuveer and colleagues used an ultrasound method called carotid artery intima-media thickness or CIMT to measure the thickness of the inner walls of the carotid arteries in 70 at-risk children. Scientists say increased thickness in the carotid artery wall indicates greater amount of fatty plaque in the arteries leading to the heart and brain. When such plaque ruptures, it can result in clots that lead to heart attack or stroke.

The children had total cholesterol of 224 (less than 170 is acceptable); LDL cholesterol (the bad kind) if 150 (less than 110 is acceptable); and triglycerides of 152 (less than 150 is acceptable). Their average age was 13; average weight was 140 pounds. Nearly 90 percent were white.

The study found that 52 of the 70 participants had a maximum CIMT of at least 0.5 millimeters, a thickness that corresponds with the CIMT of an average 45-year-old.

Experts called the findings “alarming.”

“We are raising a generation of children that are going to have a significant increase in vascular disease as they get older,” said Dr. Michael Schloss, of the New York University School of Medicine, who was not involved in the study.

The childhood obesity epidemic has become a national problem for years. The worst part is that significant changes in the US diet dating back decades, including fatty and sugary fast foods, snacks, processed foods and beverages and fewer fresh fruits and vegetables, do not seem to help very much. Also, it’s no longer a secret that most children would rather play video games and watch TV rather than do outside activities. The CDC recommends moderate activities such as walking or riding a bike for at least one hour per day.

Dr. Raghuveer’s study was not the first to trigger sign alarms about the consequence of obesity in children. For example, a study led by researchers at the University of North Carolina and published in April in the journal Dynamic Medicine showed that children having sedentary lifestyle are up to six times likelier to be at serious risk of heart disease later in life than active peers. It is no longer a secret that leading a sedentary lifestyle is linked to obesity.

The study found that almost half of the teenagers participating in the study had developed at least one characteristic of metabolic syndrome (a group of symptoms including obesity, abnormal fat levels in the blood, high blood pressure, high cholesterol and insulin problems). Metabolic syndrome can further lead to heart disease, diabetes and increased risk of stroke.

A most recent study shows that the number of children who take medications for type 2 diabetes, the form that is related to obesity, increased by 103 percent between 2002-2005. The percentage was higher among girls (up 147 percent) compared with boys (up 38.7 percent).

What can we do to prevent health problems in these kids? Dr. Raghuveer said she is hopeful that the artery build-up can be reduced if the children make important lifestyle changes, losing weight and exercising more, and in some cases take medications like cholesterol-lowering statins.