Being at risk for developing heart disease or having a stroke was once something only adults had to worry about. But now children are being added to the meld, many of them as young as three years old. In fact, a recent study found that about twice as many obese 3-to-5-years old children had elevated levels of C-reactive protein (CRP) - an inflammatory marker that experts say has been shown to predict the risk of heart disease, stroke and death under certain conditions - compared to those at healthy weights. And that difference grew to more than four times the frequency in teenagers from 15 to 17 years old.

The study, conducted by researchers from the University of North Carolina, involved 16,000 children and adolescents aged 1 to 17; nearly 70 per cent of which was a healthy weight, 15 per cent were overweight, 11 per cent were obese, and 3.5 per cent were severely obese. Overall, 40 per cent of obese children aged 3-5 had increased levels of CRP, compared with 17 per cent of those at healthy weights. By age 15-17, 83 per cent of the severely obese had increased levels of CRP, compared with 18 percent of the healthy weight adolescents.

High levels of CRP are an indication of inflammation in the body. Because the damage seen in heart disease is caused by inflammation in arterial walls, it follows that CRP could be used as a general marker for the risk of heart disease. Previous studies have linked high levels of CRP in overweight and obese adults with an increased risk of heart disease, but less has been known about CRP levels in children. "We're seeing a relationship between weight status and elevated inflammatory markers much earlier than we expected," said study lead Dr. Asheley Cockrell Skinner, an assistant professor of paediatrics at the UNC School of Medicine.

The researchers observed a similar pattern of elevation when they check two other inflammation markers, although one wasn't elevated in obese children under six. Levels of one were higher in obese children from the age of six and the other from age nine. "In this study we were unable to tease apart whether the inflammation or the obesity came first but one theory is that obesity leads to inflammation, which then leads to heart and vessel disease later on," said study co-author Dr. Eliana Perrin, who is with the Department of Paediatrics at the University of North Carolina Medical School.

"A lot more work needs to be done before we figure out the full implication of these findings, but this study tells us that very young, obese children already have more inflammation than children who are not obese - and that's very concerning." The concern of finding elevated CRP in such young children is that its effects could be cumulative. Dr. Skinner says future research is needed to see if that is the case and whether losing weight could reduce the inflammatory response in children. "It's really important to be concerned about childhood obesity and to even be concerned when they are quite young," she said. "We can't wait until they're adolescents or adults."