体力活动与结肠癌关系前瞻性研究的Meta分析

目的 索体力活动与结肠癌发生的病因学联系.方法 集和整理1979-2009年国内外公开发表的体力活动与结肠癌关系的队列研究文献,开展Meta分析.其中,各文献RR值的合并采用倒方差法或DerSimonian-Laird method(D-L)法,剂量-反应关系的评价采用方差加权的最小二乘法.结果 入Meta分析的文献共28篇.与低体力活动者相比,男、女性高体力活动者结肠癌RR值分别为0.75(95%CI:0.66～0.86)、0.85(95%CI:0.76～0.95).高质量文献分析显示体力活动与结肠癌,男性RR=0.74(95%CI:0.61～0.90)、女性接近统计学意义的RR=0.99(95%CI:0.95～1.02).男、女性中均未观察到明显的剂量-反应关系,趋势检验分别为P=0.142和P=0.417.结肠亚部位分析结果显示,增加体力活动与男性近端(右侧)结肠癌与远端(左侧)结肠癌发生均有关联,合并RR值分别为0.62(95%CI:0.45～0.85)和0.74(95%CI:0.56～0.99).结论 增加体力活动可以降低结肠癌发生的危险性.

Epidemiological prospective studies on physical activities and the risk of colon cancer: a Meta-analysis

Objective To explore the relationship between physical activity(PA) and the risk of colon cancer. Methods Cohort studies on physical activity and risk of colon cancer were identified by searching MEDLINE, EMBASE, Chinese Bio-medicine and Chinese Wanfang databases from January 1979 to December 2009. Results from the individual studies were synthetically combined in our study. Inverse variance weighting was used in fixed effects model and the random effects estimate was based on the DerSimonian-Laird method. Variance-weighted least squares method was used for trend test of summarized dose-response data. Results A total of 28 studies were included in our analysis. An inverse association between physical activities and the risk of colon cancer was observed with the relative risks (RR) as 0.75 [95% confidence interval (CI): 0.66-0.86] in males and 0.85(95%CI: 0.76-0.95)in females, respectively. However, the findings from those documents with high quality showed significant and borderline significant associations between PA and colon cancer in both males (RR=0.74, 95% CI: 0.61-0.90) and females (RR=0.99, 95% CI: 0.95-1.02). Meanwhile, the dose-response trend was not observed either in males (P=0.142) or in females (P=0.417). For men, the pooled RRs differed by subsites were 0.62(95%CI:0.45-0.85) and 0.74 (95%CI:0.56-0.99)for highest level PA, compared with lowest level PA in proximal colon and distal colon cancer,respectively. For women, the pooled RRs were 0.84 (95%CI: 0.69-1.01 ) in proximal colon and 0.75(95%CI: 0.53-1.05)in distal colon cancer, respectively. Conclusion These results added to the evidence for the protective effects in colon cancer among men and women.