Background: The goal of this study was to determine the relations between the risk of colorectal neoplasia and obesity markers: body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR).
Methods: The subjects who underwent screening colonoscopies at a Kyungpook National University Hospital in Daegu from July to December 2010 were enrolled. We defined colorectal neoplasia as tubular adenoma, advanced adenoma, or cancer. We performed a logistic regression analysis to investigate the correlations between obesity and colorectal neoplasia and a receiver operating characteristic (ROC) curve analysis to determine the cut-off obesity marker values for detecting colorectal neoplasia.
Results: Among the total of 268 subjects, 83 (31.0%) subjects had colorectal neoplasia. Subjects with neoplasia had higher BMI, WC, and WHtR than the subjects without any neoplasia. The adjusted odds ratio (aOR) of WHtR ≥0.5 with the association of neoplasia was 1.927 (95% confidence interval [CI], 1.041-3.569) in the total subjects. In women, the obesity markers of WC ≥85 cm (aOR 4.611; 95% CI, 10.166-18.240) and WHtR ≥0.5 (aOR 1.747; 95% CI, 1.149-19.617) were significantly related to neoplasia; however, there was no significant result in men. The ROC analysis showed the optimal cut-off values of BMI as >23.14 kg/m2 (P=0.002), WHtR as >0.50 (P<0.001), and WC as>82.5 cm (P=0.650) in men and >77 cm in women (P<0.001).
Conclusion: Obesity is significantly associated with the increased risk of colorectal neoplasia. WC and WHtR have more significant correlations with neoplasia; thus, obese people should undergo regular colonoscopy screenings to detect colorectal neoplasia.
Keywords: Body mass index; Colorectal neoplasms; Obesity; Waist circumference; Waist-height ratio.