Positive Fecal Occult Blood Test Associated with Diabetes

Numerous etiologies are implicated in the complications of diabetes and a link between diabetes and the predisposition to certain cancers, including colon cancer, has been established during the last decade.

The fecal occult blood test (FOBT) is a screening method used principally for detection of colon cancer or polyps; however, the relationship between FOBT and diabetes has not been explored in detail, and therefore the association between FOBT result and glycemic status, has been assessed.

Scientists at the Kanagawa University of Human Services have carried out a cross-sectional study and enrolled 12,836 apparently healthy subjects (9,258 men and 3,578 women), aged 30 to 79 years who underwent a medical health checkup at the Saitama Health Promotion Corporation in 2012. Anthropometric and laboratory tests were carried out after overnight fasting.

Serum parameters were measured using standard methods on Hitachi autoanalyzers. All subjects were classified according to their glycated hemoglobin (HbA1c) into normal (HbA1c equal to or less than 5.69%), prediabetic (HbA1c 5.7% to 6.49%) and diabetic (HbA1c equal to or greater than 6.5%) groups, regardless of whether they were being treated for diabetes. FOBT was performed automatically using a diagnostic test kit the magnetic particle agglutination method, for the detection of human hemoglobin in fecal samples. A positive FOBT was defined according to the two-day stool sampling method.

The team found that mean age and HbA1c were significantly higher in the 1,502 in the positive group than the 11,334 in negative FOBT groups. There were fewer men and current smokers in the positive FOBT group. Multivariate logistic regression analysis showed that, compared with HbA1c of less than 5.69%, HbA1c of greater than 6.5% was significantly associated with positive FOBT, independently of relevant confounders including age, sex, and past history of gastric/duodenal ulcers and colon cancer or polyp.

The authors concluded that their results indicate a significant association between diabetes and positive FOBT in a Japanese population undergoing general health screening. This supports the position that subjects with diabetes may be predisposed towards gastrointestinal cancer or may suggest the presence of microangiopathy in the gut. The study was published in the January 2017 issue of the journal Clinical Biochemistry.