Overweight as an Additional Risk Factor for Colorectal Neoplasia in Lean Population

Background: Overweight in Thailand is not as common as in Western countries. We sought to evaluate overweightas the additional risk factor that can increase the prediction of colorectal neoplasia (CRN) detection in Thais apart fromthe Asia-Pacific Colorectal Screening (APCS) score. Methods: We prospectively enrolled asymptomatic 338 subjectswho underwent screening colonoscopy between November 2016 and September 2017. All risk factors according toAPCS, BMI and the presence of metabolic syndrome were collected. Overweight was defined as BMI ≥23 kg/m2. ByAPCS score, subjects were categorized into 1) high-risk and 2) average-risk. Using the combination of APCS scoreand overweight, subjects were stratified into 4 groups; high-risk with overweight (G1), average-risk with overweight(G2), high-risk with normal weight (G3) average-risk and with normal weight (G4). Logistic regression analysis wasused to estimate the risk of detecting CRN. Results: The prevalence of CRN in the high-risk subjects was higherthan that of in the average-risk subjects (49%vs.32%; OR, 2.00; 95%CI, 1.17-3.41). After adjustment for APCS riskfactors and metabolic syndrome, overweight significantly increased the risk of detecting CRN (OR, 2.52; 95%CI,1.57-4.05). Among the 4 groups, the detection rates of CRN were significantly different (G1=64%, G2=40%, G3=32%and G4=21%, p<0.01). The relative risk of detecting CRN increased when G1 (OR 6.49; 95%CI, 2.87-14.67), and G2(2.42; 1.39-4.21) were compared with G4. Conclusions: In addition to the APCS score, overweight is an independentrisk factor for detecting CRN. In Thai population, combining overweight and APCS score may be useful to improvethe prediction for CRN.