"There is a known association between visceral fat and colonic adenomas: Patients with more visceral fat are at greater risk of having adenomatous colonic polyps," Dr. Ronald Summers, PhD, senior investigator at the U.S. National Institutes of Health, told AuntMinnie.com.
However, the reason for this association is unknown, he said. One theory is that factors circulating in the blood, secreted by the fat cells, stimulate the growth of the adenomas.
"I was interested in assessing an alternative hypothesis: whether a 'field effect' could explain the incidence of colonic adenomas," he said. "In a field effect, the disease -- in this case, colonic adenoma -- could be caused by some factor in the local environment of the colon -- in this case, a factor released by the fat in closest proximity to the colon (the 'pericolonic' fat)."
The researchers analyzed more than 1,100 patients undergoing virtual and optical colonoscopy, including 487 with pathologically proven polyps. They used automated software to analyze fat volumes on the supine scans. A logistic regression analysis showed that age, gender, pericolonic, and visceral FVF were all significant factors for predicting polyps.
Knowledge of the association between adenomas and pericolonic fat may help improve adenoma detection at VC, and could be incorporated into computer-aided polyp detection software, Summers said.
