The researchers found a continuous relationship between glycated hemoglobin (HbA1c) concentrations and colorectal cancer risk, even in individuals not known to have diabetes.
"When both glycated hemoglobin levels and diabetes status were included as variables in the same model, glycated hemoglobin remained a significant predictor of colorectal cancer risk, while the effect of diabetes was not significant," said Kay-Tee Khaw, M.D., FRCP, professor in the clinical gerontology unit of the university's School of Clinical Medicine, and principal investigator for the study. "The significantly increased risk of diabetes with colorectal cancer appeared to be mediated largely through the level of glycated hemoglobin."
Khaw noted further that glycated HbA1c could predict colorectal cancer independently of diabetes and such other risk factors as obesity and cigarette smoking and do so at concentrations below those commonly accepted as the standard for a diagnosis of diabetes.
For every one percent increase in glycated hemoglobin there was a corresponding 33 percent increase in risk across the population.
The results are based on data derived from the European Investigation into CancerNorfolk Study, a prospective population study of the connection between diet and cancer. Participants, more than 30,000 men and women, ages 45 to 79, who live in Norfolk, U.K., completed health and lifestyle questionnaires and received medical examinations. Non-fasting blood samples were drawn. Khaw and her colleagues measured glycated hemoglobin levels in the blood of the nearly 10,000 people for whom the information was available, and who did not report having cancer at th
Contact: Elizabeth Tait
American Association for Cancer Research