Researchers found much higher than expected levels of the inflammation indicator C-reactive protein, and two other inflammation markers, in obese children enrolled in a nationwide health study.
C-reactive protein (CRP) is considered by many to be an important early warning sign of heart disease and levels tend to be elevated in adults who are overweight or obese.
But the study is among the first to suggest that obesity in very young children leads to elevated CRP and other markers of systemic inflammation.
"This was definitely a surprise to us," pediatrician and study co-author Eliana M. Perrin, MD, MPH, of the University of North Carolina, Chapel Hill tells WebMD. "The fact that we saw this in children as young as 3 could certainly be cause for concern."
Elevated CRP Common in Obese Kids
The study included more than 16,000 children between the ages of 1 and 17 who took part in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2006.
Nearly 70% fell into the healthy weight range, 15% were overweight, 11% were obese, and 3.5% were very obese.
Among children between the ages of 3 and 5, just over 42% of those who were very obese had elevated CRP levels, compared to about 17% of children who were classified as healthy weight.
The difference was even greater for older children. More than four out of five (83%) very obese teens between the ages of 15 and 17 had elevated CRP levels, compared to 18% of healthy-weight teens.
Findings were similar with two other markers of systemic inflammation in adults: absolute neutrophil count (ANC) and ferritin/transferring saturation (E/T). In obese children, but not healthy-weight children, elevated E/T levels were seen beginning at age 6 and elevated ANC levels were found starting at age 9.
The study was published today online, and will also appear in the April issue of Pediatrics.
"We measured these two other markers of inflammation just in case something quirky was going on with CRP," Perrin says. "What we saw was a remarkably consistent association between early obesity and inflammation."
Impact of Early Inflammation Unclear
Although childhood obesity is a known risk factor for developing type 2 diabetes early in life, it is not yet known if the same is true for heart disease.
"We really can't say what the extra years of inflammation portend for these children," Perrin says. "It is alarming, because of what we know about the relationship in adults. But I am cautious about over-interpreting the findings, because we simply don't know the implications for young children."
Pediatrician Stephen Daniels, MD, of Children's Hospital Denver agrees that there is cause for concern.
Daniels, who is a spokesman for the American Heart Association, did not take part in the study.
"We really don't know the full impact of the obesity epidemic in children," he says. "But it is hard to imagine that [systemic] inflammation from a very early age would be a good thing."
And there are indications that, just as with type 2 diabetes, the rise in obesity is leading to earlier heart disease.
Just last week, researchers from the University of Cincinnati reported that more young- and middle-aged adults are having strokes, at the same time that the stroke rate is dropping among the elderly.
In 2005, 7.3% of strokes occurred in people younger than age 45, compared to 4.5% in 1993. The average age of a stroke patient also dropped during this time, from age 71 to 68.
The rise in obesity, high blood pressure, and diabetes among younger adults is widely believed to be the cause of this demographic shift.