BACKGROUNDFew studies have used body mass index (BMI), waist-to-hip ratio (WHR) and waist circumference (WC) at the same time to investigate the association between obesity and colorectal adenoma. This study examined the strength of association between colorectal adenoma and obesity using not only BMI, but also WHR and WC.

METHODSSubjects of this study included 1322 asymptomatic patients who underwent colonoscopy for cancer screening from January 2006 to June 2008. Anthropometric measurements, blood test results, and a self-administered questionnaire from each subject were analyzed.

RESULTSFour hundred and fourteen adenoma cases were identified in 1322 subjects. Using univariate analysis, the prevalence of adenoma was associated with BMI and WHR and was higher among the abdominal obesity group using WC guidelines of the Korean Society for the Study of Obesity, but not using WC guidelines of the International Diabetes Federation. In multiple Logistic regression analysis, general obesity (BMI ≥ 25 kg/m(2)) increased the risk of colorectal adenoma (odds ratio (OR), 1.43; 95% confidence interval (CI), 1.05 - 1.94). Also, abdominal obesity by the WC cutoffs and the highest WHR percentile group (WHR ≥ 0.95) were significantly associated with adenoma. Among three measures of obesity, however, only BMI had a persistent association with adenoma after adjusting reciprocally for BMI, WC, and WHR (OR, 1.30; 95%CI, 1.02 - 1.80; and 1.49; 1.06 - 2.10, adjusted for WC and WHR, respectively).

CONCLUSIONThe data suggest that general obesity is associated with an increased risk of colorectal adenoma.