Clinico-Epidemiologic Study of the Metabolic Syndrome and Lifestyle Factors Associated with the Risk of Colon Adenoma and Adenocarcinoma

Background: The numbers of patients with colorectal cancer and associated deaths have been increasing in Japan, probably due to rapid lifestyle changes. Prevention is clearly important and the present study aimed to clarify risk factors and to promote colon cancer screening.
Methods: We investigated lifestyle factors, biochemical data, and pathological features of 727 individuals who underwent colonoscopy. Data were subjected to statistical analysis using SPSS software.
Results: Low-grade adenoma was more frequent among the elderly and in men. All of the men and 87.5% of the women with high-grade adenoma or adenocarcinoma were aged ≥45 and ≥50 years, respectively. In women, a larger waist circumference (≥80 cm) increased the odds ratio for colon adenoma or adenocarcinoma (colon tumors) by 1.033 (95% confidence index (CI), 1.001-1.066; p=0.040). Metabolic syndrome significantly increased the odds ratio of colon tumors in men, but not in women. Cigarette smoking, drinking alcohol, and increased physical activity were significant risk factors for colon tumors in men, with odds ratios of 1.001 (95% CI, 1.000-1.002; p=0.001), 1.001 (95% CI, 1.000-1.003; p=0.047), and 1.406 (95% CI 1.038-1.904; p=0.028), respectively.
Conclusions: Colon tumors have a high prevalence in the elderly. A larger waist circumference in women and metabolic syndrome in both men and women elevate the risk of colon tumors. In addition, smoking, drinking, and excessive physical activity are risk factors for adenoma and adenocarcinoma in men. For early detection of colorectal cancer, men older than 45 years and women older than 50 years with these risk factors are recommended to undergo colonoscopy.