Ning Xin-Jie, Li Jian-Feng, Guo Hui-Long, Chen Jing-Yao
The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China.
Digestive Diseases Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
Medicine (Baltimore). 2025 May 23;104(21):e42022. doi: 10.1097/MD.0000000000042022.
The relationship between obesity and colorectal polyps remains inconclusive. This study aimed to examine whether body mass index (BMI) is causally associated with colon polyps. A two-sample Mendelian randomization (MR) analysis using the inverse variance weighted, weighted median and MR-Egger regression methods was performed. We used the publicly available summary statistics data sets of genome-wide association studies (GWAS) meta-analyses for BMI in individuals of European descent (n = 322,154; GIANT consortium) as the exposure and a GWAS for colon polyps included in the UK Biobank (total n = 463,010; case = 4779, control = 458,231) as the outcome. We selected 76 single nucleotide polymorphisms at genome-wide significance from GWASs on BMI as the instrumental variables. The inverse variance weighted method showed evidence to support a causal association between BMI and colon polyps (beta = 0.002, SE = 0.001, P = .012). MR-Egger regression revealed that directional pleiotropy was unlikely to be biasing the result (intercept = -9.3e-06;P = .889), but it showed no causal association between BMI and colon polyps (beta = 0.002, SE = 0.002, P = .09). However, the weighted median approach yielded evidence of a causal association between BMI and colon polyps (beta = 0.001, SE = 0.001, P = .01). Cochran Q test and the funnel plot indicated no evidence of heterogeneity and asymmetry, indicating no directional pleiotropy. The results of MR analysis support that BMI may be causally associated with an increased risk of colon polyps.
肥胖与结肠息肉之间的关系尚无定论。本研究旨在探讨体重指数（BMI）与结肠息肉是否存在因果关联。我们采用逆方差加权法、加权中位数法和MR-Egger回归法进行了两样本孟德尔随机化（MR）分析。我们将欧洲血统个体（n = 322,154；GIANT联盟）中全基因组关联研究（GWAS）荟萃分析的公开可用汇总统计数据集用于BMI作为暴露因素，并将英国生物银行中包含的结肠息肉GWAS（总计n = 463,010；病例 = 4779，对照 = 458,231）作为结果。我们从BMI的GWAS中选择了76个全基因组显著的单核苷酸多态性作为工具变量。逆方差加权法显示有证据支持BMI与结肠息肉之间存在因果关联（β = 0.002，标准误 = 0.001，P = 0.012）。MR-Egger回归显示定向多效性不太可能使结果产生偏差（截距 = -9.3e-06；P = 0.889），但它显示BMI与结肠息肉之间无因果关联（β = 0.002，标准误 = 0.002，P = 0.09）。然而，加权中位数法得出了BMI与结肠息肉之间存在因果关联的证据（β = 0.001，标准误 = 0.001，P = 0.01）。 Cochr an Q检验和漏斗图表明没有异质性和不对称性的证据，表明不存在定向多效性。MR分析结果支持BMI可能与结肠息肉风险增加存在因果关联。
