Researchers at Wake Forest Baptist Medical Center have found an association between obesity and the formation of blood clots in the veins of children and adolescents.

While obesity is a well-established risk factor for venous thromboembolism (VTE) in adults, previous studies in pediatric populations have yielded mixed results. The Wake Forest Baptist investigation, however, found that obesity as determined by body mass index was a statistically significant predictor of blood clot formation in juveniles.

The research is published in the current issue of the journal Hospital Pediatrics.

"This is important because the incidence of pediatric VTE has increased dramatically over the last 20 years and childhood obesity remains highly prevalent in the United States," said the study's lead author, Elizabeth Halvorson, M.D., assistant professor of pediatrics at Wake Forest Baptist.

For the study the researchers conducted a retrospective chart review of inpatients at Wake Forest Baptist's Brenner Children's Hospital between January 2000 and September 2012. They identified 88 patients ages 2 to 18 who had confirmed cases of VTE. Of these, 33 (37.5 percent) were obese, though most of them had known risk factors for blood clots in addition to obesity.

After adjusting for the other risk factors - among them bloodstream infection and time spent in an intensive care unit - the researchers found a small but statistically significant association between obesity and VTE, which can cause both acute and chronic health problems if left untreated.

"Our study presents data from a single institution with a relatively small sample size," Halvorson said. "But it does demonstrate an association between obesity and VTE in children, which should be explored further in larger future studies."