Sun Jiang-Wei, Zhao Long-Gang, Yang Yang, Ma Xiao, Wang Ying-Ying, Xiang Yong-Bing
State Key Laboratory of Oncogene and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Department of Epidemiology, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
PLoS One. 2015 Mar 24;10(3):e0119313. doi: 10.1371/journal.pone.0119313. eCollection 2015.
Epidemiological studies have reported inconsistent association between obesity and risk of bladder cancer, and the dose-response relationship between them has not been clearly defined.
We carried out a meta-analysis to summarize available evidence from epidemiological studies on this point. Relevant articles were identified by searching the PubMed and Web of Science databases through September 30, 2014. We pooled the relative risks from individual studies using random-effect model, and the dose-response relationship was estimated by using restricted cubic spline model.
Fifteen cohort studies with 38,072 bladder cancer cases among 14,201,500 participants were included. Compared to normal weight, the pooled relative risks and corresponding 95% confidence intervals of bladder cancer were 1.07(1.01-1.14) and 1.10(1.06-1.14) for preobese and obesity, with moderate (I² = 37.6%, P = 0.029) and low (I² = 15.5%, P = 0.241) heterogeneities between studies, respectively. In a dose-response meta-analysis, body mass index (BMI) was associated with bladder cancer risk in a linear fashion (P(non-linearity) = 0.467) and the risk increased by 4.2% for each 5 kg/m2 increase. No significant publication bias was found (P = 0.912 for Begg's test, P = 0.712 for Egger's test).
Findings from this dose-response meta-analysis suggest obesity is associated with linear-increased risk of bladder cancer.
流行病学研究报告了肥胖与膀胱癌风险之间的关联并不一致，且二者之间的剂量反应关系尚未明确界定。
我们进行了一项荟萃分析，以总结关于这一点的流行病学研究中的现有证据。通过检索截至2014年9月30日的PubMed和Web of Science数据库来识别相关文章。我们使用随机效应模型汇总了个体研究中的相对风险，并使用受限立方样条模型估计了剂量反应关系。
纳入了15项队列研究，涉及14201500名参与者中的38072例膀胱癌病例。与正常体重相比，超重前期和肥胖人群患膀胱癌的合并相对风险及相应的95%置信区间分别为1.07（1.01 - 1.14）和1.10（1.06 - 1.14），研究间的异质性分别为中度（I² = 37.6%，P = 0.029）和低度（I² = 15.5%，P = 0.241）。在剂量反应荟萃分析中，体重指数（BMI）与膀胱癌风险呈线性相关（P（非线性）= 0.467），每增加5 kg/m²风险增加4.2%。未发现显著的发表偏倚（Begg检验P = 0.912，Egger检验P = 0.712）。
这项剂量反应荟萃分析的结果表明，肥胖与膀胱癌风险呈线性增加有关。
