Too little sleep linked to colon cancer

CLEVELAND, Feb. 9 (UPI) -- Too little sleep is linked to higher risk of obesity, heart disease, diabetes and now colon cancer, U.S. researchers suggest.

Dr. Li Li of University Hospitals Case Medical Center and Case Western Reserve University School of Medicine says people who average fewer than 6 hours of sleep a night had an almost 50 percent increase in the risk of colorectal adenomas compared with those sleeping at least 7 hours per night.

Adenomas are a precursor to cancer tumors, and left untreated, they can turn malignant, Li says.

"To our knowledge, this is the first study to report a significant association of sleep duration and colorectal adenomas," Li says in a statement. "A short amount of sleep can now be viewed as a new risk factor for the development of the development of colon cancer."

Patients were surveyed by phone on their sleep prior to coming into the hospital for scheduled colonoscopies.

The study, published in the journal Cancer, found that of the 1,240 patients, 338 were diagnosed with colorectal adenomas at their colonoscopy and the patients with adenomas were found to have reported sleeping less than 6 hours compared with patients without adenomas -- the control -- even after adjusting for family history, smoking and weight.