It has been reported that alcohol intake and folate deficiency are associated with an increased risk of colorectal adenomas and carcinomas. Mean corpuscular volume (MCV) of red blood cells has been reported to be increased in these conditions. The purpose of this study was to assess the association between MCV and risk of colorectal adenoma.The subjects were 497 middle-aged (45-65 yr old) men who underwent both barium enema examination and total colonoscopy. The subjects answered a questionnaire regarding their alcohol consumption history, and their blood samples were analyzed. The subjects were divided into four groups three times: with or without alcoholism, and with or without adenoma according to alcohol intake, and according to the MCV value. Various variables were compared among the groups, and the odds ratios of adenoma were calculated.The MCV was higher in the alcoholic group than in the nonalcoholic group (p0.01) and in patients with adenoma than in those without adenoma (p0.0001). When the subjects were stratified by alcohol intake, the MCV value had a higher significant difference than alcohol intake, between patients with adenoma and those without adenoma. As for the MCV value, the odds ratio (95% confidence interval) of adenoma was 1.00 (referent); (92), 1.20 (0.71-1.69); (or =92 but95), 2.61 (2.07-3.15); (or =95 but98); and 3.62 (2.99-4.25); (or =98).A high MCV value may be used as a simple index of the risk of colorectal adenomas, regardless of alcohol consumption.
