Impact of obesity and metabolic abnormalities on the risk of metachronous colorectal neoplasia after polypectomy in men

Background and Aim: Obesity and metabolic syndrome are well-known risk factors for the development of metachronous colorectal neoplasia (CRN). However, data on the risks of metachronous CRN among subgroups according to obesity and metabolic status are scarce. Therefore, we aimed to compare the risk of metachronous CRN among men with different obesity and metabolic status. Methods: In total, 8059 asymptomatic men who underwent ≥ 1 adenoma removal between 2010 and 2014 and follow-up colonoscopic surveillance until 2017 were categorized into four groups according to obesity and metabolic status: metabolically healthy non-obese (MHNO), metabolically healthy obese (MHO), metabolically unhealthy non-obese (MUNO), and metabolically unhealthy obese (MUO). Results: Of the 8059 men, 2389 (29.6%), 351 (4.4%), 1986 (24.6%), and 3333 (41.4%) subjects were assigned to the MHNO, MHO, MUNO, and MUO groups, respectively. The mean surveillance interval was 3.5 ± 1.4 years. Compared to the MHNO group, the risk of metachronous advanced CRN was significantly increased in the MUO group (adjusted hazard ratio [HR] = 1.50; 95% confidence interval [CI]: 1.02–2.19), but not in the MHO and MUNO groups, while the risk of metachronous overall CRN significantly increased in the MUNO (adjusted HR = 1.12; 95% CI: 1.01–1.24) and MUO groups (adjusted HR = 1.17; 95% CI: 1.07–1.29), but not in the MHO group. Conclusions: Men who had both obesity and poor metabolic health were found to be at an increased risk of metachronous advanced CRN, suggesting that MUO men may need to undergo more intensive surveillance colonoscopy after polypectomy.