Heart disease in children: think heart disease and atherosclerosis and you think about middle-aged or elderly men and women. Now look at your 12-year-old. There's a pretty good chance she's already got fatty streaks in her aorta, the body's main artery, an early sign of atherosclerosis. She may also have high cholesterol.

In fact, up to one-third of American children, from age two through the teenage years, have high cholesterol. Compared with their counterparts in many other countries, American children and adolescents also have higher blood cholesterol levels and higher intakes of saturated fatty acids and cholesterol. (18) Young children, even babies, can also have high blood pressure. (19)

So in the summer of 2002, the American Heart Association began recommending that health care professionals start measuring children's blood pressure at age three and blood cholesterol at age five. (19,20) The American Academy of Pediatrics recommends cholesterol tests for children age two or older, if their parents or grandparents had heart disease or vascular disease before age 55, or if their parents have cholesterol levels of 240 mg/dL or higher. (18)

Cholesterol ranges to know in children ages two- to 19-years-old:

* Total cholesterol levels should be less than 170 mg/dL.

* LDL cholesterol levels should be less than 110 mg/dL.

* Total cholesterol levels greater than 200 mg/dL and/or LDL levels greater than 130 mg/dL are considered high.

Blood pressure levels in children vary by age, height and weight, so talk to your health care professional about what your child's should be.

"There is overwhelming evidence now that atherosclerosis, a build up of plaque in the arteries, starts in childhood, not when you're 50 or 60," says David J. Driscoll, MD, professor of pediatrics and director of the Division of Pediatric Cardiology at the Mayo Clinic in Rochester, MN. We know this from autopsies performed on children who die of accidental deaths, he notes. Other studies on young soldiers who died in Korea and Vietnam showed that by their early 20s, many already had the beginnings of atherosclerosis, "Some of them with pretty significantly advanced disease."

We also know that there's a correlation between cholesterol and other blood fat levels in children and the degree of fatty streaking or atherosclerosis in their arteries, he says. In fact, children and adolescents with high cholesterol levels are more likely than the general population to have high levels as adults. (19)

What we don't yet know is if lowering a child's cholesterol levels changes their risk later in life for developing coronary disease, he says. "Intuitively, you would think that it would, but those studies haven't been done yet." And a substantial number of children with high cholesterol levels do become adults with desirable cholesterol levels without intervention. (18)

Nonetheless, the U.S. National Cholesterol Education Program recommends cholesterol lowering drugs for children over age 10 whose LDL (that's the "bad" cholesterol) remains high even after they've changed their diet. Until fairly recently, the most common class of such drugs, statins, were not approved for use in children and few large studies on their effects in children had been conducted.

But a study published in the October 2002 issue of the journal Circulation found the cholesterol-lowering drug, simvastatin (Zocor), a statin, significantly reduced cholesterol levels in children with an inherited form of high cholesterol. The study on 173 children between ages nine and 18 also found that even after 48 weeks on the drug, there was no effect on growth or progression of puberty. (21)

Today, statins are generally considered safe to use in children and adolescents, says Dr. Driscoll, "although we use them a bit more cautiously than with adults because if you take a 55-year-old person and put them on a drug for the rest of their life and they live to be 85, that's 30 years. But, with a 15-year-old, you may be talking about a very long time on that drug."