Older women who have high levels of serum glucose are at increased risk for colorectal cancer, a longitudinal study found. Compared with postmenopausal women whose glucose levels were in the lowest tertile, those in the highest tertile had a multivariable adjusted hazard ratio for colorectal cancer of 1.74 (95% CI 0.97 to 3.15, P for trend=0.06), according to Geoffrey C. Kabat, MD, of Albert Einstein College of Medicine in New York, and colleagues.

And the risk was even higher when the analysis was specifically for colon cancer (HR 2.25, 95% CI 1.12 to 4.51, P for trend=0.02), they reported online in the British Journal of Cancer. Although obesity and related conditions such as diabetes and the metabolic syndrome have been linked with colorectal cancer, it has not been known whether the risk relates to levels of circulating insulin or glucose.

Insulin theoretically could contribute in that it is anti-apoptotic and mitogenic, whereas glucose might increase the risk by providing an energy source for malignant cells, the researchers explained