Department of Endocrinology and Metabolism, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China.
Int J Cancer. 2018 Feb 15;142(4):729-740. doi: 10.1002/ijc.31100. Epub 2017 Oct 26.
While there is convincing evidence that excess body fatness in adulthood is positively associated with colorectal cancer risk, the association between body fatness at an early age (≤30 years) and the risk of colorectal cancer has been equivocal. The present meta-analysis was performed to clarify this association. PubMed and Web of Science databases were searched for relevant studies that investigated this association. The risk estimates from each study were transformed into a continuous variable for each 5 kg/m increase in body mass index (BMI). A random effects model was used to calculate the summary relative risks (RRs) with 95% confidence intervals (CIs). A total of 15 observational studies (13 cohort studies and two case-control studies) were included in this meta-analysis. Each 5 kg/m increase in BMI was significantly associated with a 13% (RR 1.13, 95% CI 1.08, 1.19), 17% (RR 1.17, 95% CI 1.09, 1.25) and 8% (RR 1.08, 95% CI 1.04, 1.11) higher risk of colorectal cancer overall, in men, and in women, respectively. Substantial heterogeneity was observed across studies. Based on the anatomic subsite, each 5 kg/m increase in BMI was significantly associated with a 14% (RR 1.14, 95% CI 1.07, 1.22) higher risk of colon cancer, whereas no association (RR 1.03, 95% CI 0.95, 1.13) was observed with rectal cancer. In summary, body fatness at an early age may affect colon cancer risk later in life. Prevention of overweight and obesity in young individuals should be emphasized to prevent early-onset colon cancer attributed to excess body fatness.
虽然有确凿的证据表明成年人的体脂肪过多与结直肠癌风险呈正相关，但早期（≤30 岁）体脂肪与结直肠癌风险之间的关联尚无定论。本荟萃分析旨在阐明这种关联。我们检索了 PubMed 和 Web of Science 数据库，以寻找研究这种关联的相关研究。从每项研究中获得的风险估计值被转换为每 5kg/m2 体重指数（BMI）增加的连续变量。使用随机效应模型计算汇总相对风险（RR）及其 95%置信区间（CI）。这项荟萃分析共纳入了 15 项观察性研究（13 项队列研究和 2 项病例对照研究）。BMI 每增加 5kg/m2，与结直肠癌总体、男性和女性的风险分别增加 13%（RR 1.13，95%CI 1.08，1.19）、17%（RR 1.17，95%CI 1.09，1.25）和 8%（RR 1.08，95%CI 1.04，1.11）显著相关。研究之间存在明显的异质性。根据解剖部位，BMI 每增加 5kg/m2 与结肠癌风险增加 14%（RR 1.14，95%CI 1.07，1.22）显著相关，而与直肠癌无关联（RR 1.03，95%CI 0.95，1.13）。总之，年轻时的体脂肪可能会影响以后的结肠癌风险。应强调预防年轻人超重和肥胖，以预防因体脂肪过多而导致的早发性结肠癌。
