NEW ORLEANS — Adults who have been overweight since early adulthood are nearly twice as likely to have colon adenomas as those with a history of normal weight.
The findings reinforce the benefit of maintaining a healthy weight throughout life, Dr. Fritz Francois of New York University said in a written statement.
“Our conclusions suggest that the chronicity of obesity is a significant risk factor for developing colon cancer. Given the continued rise in early-onset obesity, especially in minority populations, there is a need for interventions and lifestyle modifications earlier in life.”
The researchers conducted a prospective study of 1,865 patients referred for a screening colonoscopy, said Ian Fagan, a fourth-year medical student who presented the findings at the meeting. Their mean age was 57 years. Body mass index (BMI) was normal in 38%, whereas 39% were overweight and 23% were obese. A total of 12% were current smokers.
The patients provided information allowing the researchers to estimate their BMI and waist circumference at age 10 and age 20. The investigators compared the past weights to the finding of any adenoma, including advanced neoplasia, during the colonoscopy.
The subjects were divided into three groups: those who had normal weights at age 20 and at present, those who had a normal weight at 20 and were now overweight or obese, and those who had been overweight or obese since age 20.
“Race and ethnicity had a significant impact on weight change,” Mr. Fagan said. Sixty-one percent of Hispanics fell into the group that changed from normal weight to overweight or obese, as well as 50% of blacks, 46% of whites, and 7% of Asians.
Adenomas were significantly more common among patients who had been overweight or obese since age 10 (at a rate of 27%) and among those who went from normal weight to overweight (19%), compared with those who had maintained a normal weight (13%).
After controlling for age, gender, current BMI, U.S. birth, and red meat consumption, the investigators found that becoming overweight or obese in early adulthood almost doubled the risk of an adenoma on screening colonoscopy (odds ratio 1.8). Mr. Fagan did not present a risk analysis for subjects who had been overweight since childhood, saying that the number of subjects in that group was not sufficient.
Disclosures: Neither Mr. Fagan nor Dr. Francois had financial conflicts.
Adenomas were significantly more common among patients who had been overweight or obese since age 10.
Source: Ian Fagan