Insulin increase in colon cancerogenesis: a case-control study

Our aim was to establish whether individuals who develop colon cancer have elevated blood insulin concentrations.

This was a case-control study in which 56 normoglycemic patients with colon cancer and a corresponding control group were investigated at the Clinical Hospital Split from April 1998 to April 1999. Data on age, weight, height, and sex of examinees were recorded and concentrations of glucose, insulin, and C-peptide were measured first in the morning before breakfast and again 90 min after breakfast.

In the male group of colon cancer patients, we found statistically significant higher blood insulin concentrations 90 min after breakfast (median 34.7 mIU/L, range 3.3-162.6 mIU/L) in comparison to male control group (median 20.7 mIU/L, range 3.1-122.1 mIU/L) (p=0.044). Concentration of C-peptide in blood 90 min after breakfast (median 3.28 nmol/L, range 0.38-6.1 nmol/L) was higher in the male group of colon cancer patients than in male control group (median 1.68 nmol/L, range 0.26-4.26 nmol/L) (p=0.001). No difference was found in concentrations of insulin, C-peptide, and glucose in blood measured in the morning before breakfast between the male group of colon cancer patients and male control group. Ratio of insulin 90 min after breakfast with respect to insulin in the morning before breakfast was higher in the male group of colon cancer patients (median 4.65, range 0.83-22.1) than in male control group (median 1.78, range 0.38-8.75) (p=0.005). Ratio of C-peptide 90 min after breakfast with respect to fasting C-peptide was higher in the male group of colon cancer patients (median 3.22, range 0.74-11.9) than in male control group (median 1.42, range 0.54-6.0) (p=0.001). Women with colon cancer also had statistically significant higher ratio of insulin and C-peptide with respect to female control group. In the female group of colon cancer patients, median for ratio of C-peptide was 2.42 (range 0.43-8.87), while in female control group it was 1.19 (range 0.62-15.4) (p=0.025). Median for ratio of insulin in the female group of colon cancer patients was 4.23 (range 0.25-8.54), while in female control group it was 1.17 (range 0.29-26.89) (p=0.007).

There was a higher increase of insulin 90 min after breakfast in the group of patients with colon cancer than in control group.