SAN ANTONIO – Overweight and obese adults had an increased risk of recurrent adenomas during short-term and long-term follow-up, based on data from patients with colorectal adenomas at baseline.
Previous studies have shown a short-term association between obesity and increased risk of adenoma recurrence, said Dr. Adeyinka Laiyemo of Howard University in Washington. To assess the long-term impact of overweight and obesity on adenoma risk, Dr. Laiyemo and colleagues reviewed data from participants in the Polyp Prevention Trial, a multicenter study of the effect of a low-fat, high-fiber diet on adenoma recurrence. The results were presented at the annual scientific meeting of the American College of Gastroenterology.
Upon completion of the 4-year (short-term) study, a subset of 760 participants agreed to continue in an extended, passive long-term follow-up without dietary restrictions. Their colonoscopy reports were analyzed for up to 12 years, with an average follow-up period of 8.4 years.
During the long-term follow-up, obese patients had a significant 20% increase in risk for any adenoma and a 25% nonsignificant increase in risk for an advanced adenoma, compared with patients of normal weight. Overweight patients had an 18% significant increase in risk of any adenoma and a 14% nonsignificant increase in risk of advanced adenoma, compared with normal-weight patients.
Analysis of the initial 4-year follow-up period also showed increased risk for participants with excess body weight. Obese patients had a 19% increase in risk for any adenoma and a 23% increase in risk for advanced adenoma compared with normal-weight patients, although neither of these were statistically significant. Overweight patients had a 23% significant increase in risk for any adenoma and a 18% nonsignificant increase in risk for advanced adenomas compared with normal-weight patients during the 4-year period.
The average age of the participants was 60 years, and 66% were men. Approximately 25% of the participants were of normal weight (body mass index less than 25 kg/m2), 50% were overweight (BMI of 25-29), and 25% were obese (BMI of 30 or higher).
"This suggests that lifestyle modification should be encouraged," Dr. Laiyemo said. The study was strengthened by the inclusion of patients from eight different centers, but was limited by the lack of data on morbidly obese patients, he added.
More research is needed to determine whether overweight or obese patients with baseline polyps should be reexamined more frequently than normal-weight patients. For now, however, if these patients have baseline polyps, they need to know that their risk for recurrent adenomas is increased, Dr. Amy E. Foxx-Orenstein of the Mayo Clinic, Scottsdale, Ariz., said at a press conference.
Another message that patients need to hear is that a good prep is important, to get the best possible information from each colonoscopy, Dr. David A. Johnson of Eastern Virginia School of Medicine, Norfolk, said at the press conference.
Dr. Laiyemo had no financial conflicts to disclose.