Study: High Glucose Levels Increase Chance of Developing Colorectal Cancer

New research indicates that people with high levels of glucose are at higher risk to developing colorectal tumors, which can lead to colorectal cancer. This is particularly important given the fact that 20 million people in the United States have diabetes and an estimated 54 million people have pre-diabetes.

"This is the first study to determine whether elevated glucose or insulin as measured when or shortly after a patient has had polyps removed during a baseline colonoscopy procedure increases their risk for subsequent recurrence of pre-cancerous growths in the colon," said Andrew Flood, PhD, of the University of Minnesota and lead author of the study in a press release. "The results of our study have important clinical implications with respect to maintenance of glycemic control in patients with a history of colorectal polyps."

Prediabetes is a condition when glucose levels are higher than normal, but still low enough for the patient not to be diagnosed with diabetes. By determining whether or not high glucose levels affect the rate of occurrence of colorectal cancer, instances of colorectal cancer recurrence could be prevented. This study was a subset of a larger study called the Polyp Prevention Trial.

The Poly Prevention Trial is headed by the National Cancer Institute and follows the affects of a low fat, high fiber diet on over 2000 men and women. The diet is also high in fruits and vegetables and was developed in an attempt to prevent precancerous polyps in the colon or rectum. The people in the study have all been previously diagnosed with a polyp within six months before participating in the study.

People with both high levels of glucose along with high levels of insulin increased their risk of developing another colorectal tumor by fifty percent. In the trial, 39.6 of all people developed another colorectal tumor within four years. Patients with high glucose were 2.4 times more likely to have a colorectal tumor recurrence.

Also, patients with the increased glucose levels had high BMI's and high waist to hip ratios. They also tended to be older than the average subject, male, smokers, a minority, and did not have a college degree. Furthermore, people with a history of colorectal cancer in their family seemed to be even more at risk.

The researchers concluded that it is particularly important to manage glucose levels after a patient has had colorectal cancer or a tumor removed. In the Polyp Prevention Trial, it was found that even a mildly elevated glucose level showed increased rates of colorectal cancer.

Sources:

American Gastroenterological Association, "Increased glucose level is a strong risk factor for colorectal cancer" Eurekalert