Alcohol, cigarette smoking, dietary factors and the risk of colorectal adenomas and hyperplastic polyps--a case control study.

Epidemiological studies on the association between lifestyle factors and the risk of colorectal polyps have led to conflicting results. The aim of the present study was to assess the relationship between alcohol consumption, dietary risk factors, cigarette smoking and colorectal adenomas or hyperplastic polyps, respectively. In formation on alcohol consumption, a detailed dietary history, cigarette smoking and intake of non-steroidal anti-inflammatory drugs was collected among 502 Caucasian subjects undergoing complete colonoscopy, 207 with colorectal adenomas, 71 with hyperplastic polyps and 224 controls with no polyps. Using univariate analysis significant risk factors for adenomas were age above 55 years, male sex, BMI > 24 (OR 1.91 [1.26-2.88]), an intake of ham + sausage > 15 g/day (OR 1.87 [1.12-3.11]) and smoking (OR 1.71 [1.17-2.5]). The association with alcohol intake > 7 g/day was not significant (OR 1.42 [0.97-2.07], p = 0.071). In the multiple logistic regression only age > 55 years (OR 2.97 [1.94-4.52]), male sex (OR 2.12 [1.54-3.6]) and smoking (OR 1.56 [1.01-2.39]) were significant risk factors for adenomas. Unexpectedly the mean consumption of alcohol, wine and beer, was significantly lower in subjects in whom adenomas were localized only in the rectum compared to those having adenomas in the sigmoid or in the proximal colon. Significant risk factors in subjects with hyperplastic polyps on univariate analysis were intake of > 15 g of ham and sausage/day (OR 3.70 [1.49-9.19]), smoking (OR 1.79 [1.04-3.06]) and male sex. In the multiple logistic regression only intake of > 15 g/day of ham + sausage and male sex were significant risk factors (OR 3.24 [1.23-140.8] and 1.83 [1.05-318], respectively). When controlling for other potential risk factors, smoking was the only significant lifestyle risk factor for colorectal adenomas and the intake of ham and sausage > 15 g/day for hyperplastic polyps. The intake of alcohol, wine and beer were markedly higher in subjects with adenomas of the colon compared to those with adenomas in the rectum.