Markers of insulin resistance and colorectal cancer mortality

A link between insulin metabolism and colorectal cancer has been hypothesiz ed, supported by a series of potential physiological mechanisms, and confir med by a number of reports in experimental animals. However, the evidence i n humans is limited and mostly indirect. The aim of the present report is to analyze whether individuals with a clus ter of metabolic abnormalities associated with abnormalities in insulin met abolism experience higher mortality for colorectal cancer than those withou t this cluster of metabolic abnormalities. A total of 21,311 men and 15,991 women 20-69 years of age were followed-up for an average of 7 years as part of the Risk Factors and Life Expectancy P roject, a pooling of a number of epidemiological studies conducted in Italy . Our analyses indicate that participants with high levels of blood glucose a nd a cluster of metabolic abnormalities linked to insulin resistance experi enced a significant increased risk of colorectal cancer mortality compared with participants without the cluster. For the presence of the cluster of m etabolic abnormalities, the calculated hazard ratios and 95% Cls were 2.96 (1.05-8.31) for men, 2.71 (0.59-12.50) for women, and 2.99 (1.27-7.01) when both sexes were combined. These associations were independent from the pot ential confounding effect of age, drinking of alcoholic beverages, and smok ing. Our findings are supportive of the hypotheses that glucose metabolism hyper insulinemia, insulin resistance, and metabolic abnormalities associated wit h it may play a significant role in the etiology of colorectal cancer.