Association between investigator-measured body-mass index and colorectal adenoma: a systematic review and meta-analysis of 168,201 subjects

• Published in: European journal of epidemiology Vol. 33; no. 1; pp. 15 - 26
• Main Authors: Wong, Martin Chi-sang, Chan, Chun-hei, Cheung, Wilson, Fung, Din-hei, Liang, Miaoyin, Huang, Jason Li-wen, Wang, Yan-hong, Jiang, Johnny Yu, Yu, Chun-pong, Wang, Harry Haoxiang, Wu, Justin Che-yuen, Chan, Francis Ka-leung, Sung, Joseph Jao-yiu
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.01.2018; Springer Netherlands; Springer Nature B.V
• Subjects: Adenoma; Adenoma - ethnology; Adenoma - etiology; Adenoma - pathology; Body Mass Index; Body size; Cancer screening; Cardiology; Colon; Colorectal cancer; Colorectal carcinoma; Colorectal Neoplasms - ethnology; Colorectal Neoplasms - etiology; Colorectal Neoplasms - pathology; Colorectal Neoplasms - prevention & control; Epidemiology; Female; Heterogeneity; Humans; Infectious Diseases; Male; Medical screening; Medicine; Medicine & Public Health; META-ANALYSIS; Minority & ethnic groups; Obesity - complications; Obesity - diagnosis; Obesity - ethnology; Observational studies; Oncology; Public Health; Regression analysis; Risk; Risk Factors; Statistical analysis; Studies; Systematic review; Tumors; Body mass index; Colorectal adenoma; Association; Meta-analysis
• ISSN: 0393-2990; 1573-7284
• DOI: 10.1007/s10654-017-0336-x

The objective of this meta-analysis is to evaluate the odds of colorectal adenoma (CRA) in colorectal cancer screening participants with different body mass index (BMI) levels, and examine if this association was different according to gender and ethnicity. The EMBASE and MEDLINE were searched to enroll high quality observational studies that examined the association between investigator-measured BMI and colonoscopy-diagnosed CRA. Data were independently extracted by two reviewers. A random-effects meta-analysis was conducted to estimate the summary odds ratio (SOR) for the association between BMI and CRA. The Cochran's Q statistic and I² analyses were used to assess the heterogeneity. A total of 17 studies (168,201 subjects) were included. When compared with subjects having BMI < 25, individuals with BMI 25-30 had significantly higher risk of CRA (SOR 1.44, 95% CI 1.30-1.61; I² = 43.0%). Subjects with BMI ≥ 30 had similarly higher risk of CRA (SOR 1.42, 95% CI 1.24-1.63; I² = 18.5%). The heterogeneity was mild to moderate among studies. The associations were significantly higher than estimates by previous meta-analyses. There was no publication bias detected (Egger's regression test, p = 0.584). Subgroup analysis showed that the magnitude of association was significantly higher in female than male subjects (SOR 1.43, 95% CI 1.30-1.58 vs. SOR 1.16,95% CI 1.07-1.24; different among different ethnic groups (SOR 1.72, 1.44 and 0.88 in White, Asians and Africans, respectively) being insignificant in Africans; and no difference exists among different study designs. In summary, the risk conferred by BMI for CRA was significantly higher than that reported previously. These findings bear implications in CRA risk estimation.