Abstract
Objective: Our objective was to conduct a comparative study of the risk factors for the occurrence of colorectal adenomatous polyps (adenoma) from the perspective of chronological changes in lifestyles over a period of time.
Methods: Over a 15-year period, 16,647 subjects underwent colonoscopy for the first time at the Health Care Center of Takano Hospital. Risk factors for the development of adenoma were divided into those for the first half (from April 1992 to March 1998) and those for the second half (from April 1998 to March 2007) of the examination period. Subjects were compared by age, body mass index (BMI<18.5, 18.5≦BMI<25, 25≦BM<30, 30≦BMI<35, and 3≦BMI), total-cholesterol (Tcho), HDL-cholesterol (HDL), triglycerides (TG), LDL-cholesterol (LDL) and fasting blood-sugar level (FBS). The odds ratios (OR) were calculated by multivariate logistic regression analysis.
Results: The risk of developing adenoma for men in the first half of the examination period increased significantly with an OR of 1.031 for aging, 1.001 for TG, and 1.005 for FBS. In the second half, the risk increased by 1.028 for aging, when the OR for those with 18.5≦BMI<25 was set at 1, 1.28 for those with 25≦BM<30, and 2.05 for those with 35≦BMI. The risk increased by 1.001 times for TG. However, an increase in HDL significantly decreased the risk to 0.994. On the other hand, although no risks were observed for women in the first half of the examination period, in the second half, ORs of 1.029 for aging, and 1.002 for TG were noted.
Conclusions: The risk of developing adenoma was found to differ with annual lifestyle trends. In particular, in the second half, the factors pertaining to obesity were found to be risk factors inducing adenoma. Therefore, we concluded that weight control would be effective in the primary prevention of colorectal cancer.
