Aging, Smoking, Dyslipidemia, and Obesity Are Independently Associated With the Prevalence of Colorectal Neoplasia in Japan: Analyses of Comprehensive Health Checkup Data

Abstract

Introduction: Colorectal cancer (CRC) is the third leading cause of cancer death in Japan. For the past decades, the incidence and mortality rate of CRC has been increased in Japan which corresponds with the economic development and concomitant shifts from traditional lifestyle towards a westernized lifestyle. We investigated the risk factors such as metabolic and lifestyle factors for the occurrence of colorectal neoplasia (CRN) by using comprehensive health checkup data. Methods: We conducted a retrospective analysis in clinical practice at a single center. Among 6698 subjects who took comprehensive health checkup at our hospital between in August 2012 and March 2015, 1511 subjects who also underwent screening colonoscopy were enrolled. In the present study, CRN was defined as adenomatous polyp ≥ 5 mm in size and adenocarcinoma. A diagnosis of metabolic syndrome (MetS) was made by Metabolic Syndrome Diagnostic Criteria Exploratory Committee in Japan. Demographic characteristics, anthropometric measurements, visceral fat area (VFA) measured at the umbilical level by computed tomography, hematological metabolic parameters, degree of liver fat evaluated by ultrasonography, and current smoking and drinking habits were assessed. Association between variables and CRN was evaluated by univariate analysis using t-test, χ2 test, Mann-Whitney test, and then by multivariate analysis using multiple logistic regression model. A p value < 0.05 was considered statistically significant. Results: One hundred and seventy subjects had CRN (11.3%) and 5 had invasive colorectal cancer (0.3%). Three hundred and fifty-eight subjects were diagnosed as MetS (24.9%) and presence of MetS was significantly associated with CRN (MetS (+): 16.2% vs MetS (-): 9.6%, p < 0.001). Univariate analysis identified significant association of age, body mass index (BMI), VFA, systolic blood pressure, lowdensity lipoprotein (LDL)-cholesterol, triglycerides (TG), fasting plasma glucose, hemoglobin A1c (HbA1c), fatty liver, current smoking habits, current drinking habits and ≥ 10 kg weight gain compared with the body weight at the age of twenty with prevalence of CRN. Logistic regression analysis revealed that age (odds ratio (OR): 1.048), BMI (OR: 1.061), LDL-cholesterol (OR: 1.008), and current smoking (OR: 2.335) were independent factors associated with CRN prevalence. Conclusion: The present study demonstrated that aging, smoking, dyslipidemia and obesity (high BMI) might be risk factors for CRN in Japan.Table 1: Multivariate analysis of risk factors for colorectal neoplasia prevalence