Diabetes and risk for colon polyps

Colorectal cancer has been linked to obesity and insulin resistance has been implicated in the pathogenesis. We know that 95% of colorectal cancer arises from colorectal polyps of adenoma type. Although diabetes mellitus type 2 has been linked to cancer of colon/rectum, the data regarding it association with colorectal adenoma polyps is sparse.

Dr. Jill Elwing and colleagues from Washington University School of Medicine in St. Louis, Missouri studied the association between diabetes mellitus (type 2) and adenoma polyps in colon or rectum. They published their findings in the American Journal of Gastroenterology (August 2006) in a study titled, "Type 2 diabetes mellitus: the impact on colorectal adenoma risk in women ."

The authors wished to examine if the diabetic women have increased rates of colorectal adenomas relative to a group of nondiabetic women. Confounding risk factors studied included age, race, diabetes, hypertension, hypercholesterolemia, body mass index, and the use of nonsteroidal anti-inflammatory drugs.

These investigators found that risk of any adenoma among diabetic women was 37% as compared to 24% in controls. Rate of advanced adenomas was also higher (14%vs 6%).

Furthermore, adenoma rate among obese diabetic women was 42% as compared to 23% among nonobese, nondiabetic women.

The authors concluded that women with type 2 diabetes mellitus have higher rates of colorectal adenomas as compared to lean and nondiabetic women. These results lend further support to the hypothesis that type 2 diabetes plays an important role in the string of the adenoma-carcinoma sequence.