Weight gain in early adulthood may raise adenoma risk

Adults who become overweight or obese during early adulthood are nearly twice as likely to develop colon adenomas as are individuals with a history of normal body weight in early adulthood, according to a study presented at the annual Digestive Disease Week.

“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 to help lessen this serious health risk later in life,” said the New York University in a written statement.

Work on the study presented the data. The investigators conducted a prospective study of 1,865 patients who were referred for a screening colonoscopy. Their mean age was 57 years.

At the time of the study, the participants’ body mass index (BMI) was normal in 38 percent, whereas 39 percent were classified as overweight and obese. In addition, a total of 12 percent were current smokers.

Patients provided information allowing the researchers to estimate their BMI and waist circumference at age 10 and age 20. Patients did so by recalling their clothing size and completing a validated questionnaire that included sketches of different body outlines.

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.

“One thing we noticed right away was that race and ethnicity had a significant impact on weight change since early childhood.”

Sixty-one percent of Hispanics fell into the group that changed from normal weight to overweight or obese, as well as 50 percent of blacks, 46 percent of whites, and 7 percent Asians.

Adenomas were significantly more common among patients who had been overweight or obese since age 10 (at a rate of 27 percent) and among those who went from normal weight to overweight (19 percent), compared with those who had maintained a normal weight (13 percent).

After controlling for age, gender, current BMI, and red meat consumption, the investigators found that becoming overweight or obese in early adulthood almost doubled the risk of finding an adenoma on screening colonoscopy.

For the group of subjects who had been overweight since childhood, the sample size was too small to sufficiently power the analysis.

“Several factors that are not considered in current guidelines are emerging as important risk modifiers for colorectal cancer, including diabetes, metabolic syndrome, obesity, and cigarette smoking.”

“This finding about chronicity of obesity is another important observation that may eventually help us develop more detailed risk stratification schemes for colorectal cancer screening,” said distinguish professor of medicine at Indiana University, Indianapolis, and director of endoscopy at Indiana University Hospital.