Department of Gastroenterology, Xinhua Hospital, Shanghai Jiaotong University, School of Medicine, 1665 Kongjiang Road, Shanghai, People's Republic of China.
Oncologist. 2012;17(11):1461-8. doi: 10.1634/theoncologist.2012-0066. Epub 2012 Sep 6.
Questions remain about the dose-response relationship between body mass index (BMI) and primary liver cancer (PLC) risk, possible confounding by hepatitis virus infection, and differences by gender or geographic location. We performed a meta-analysis of prospective studies to explore these issues.
We searched PubMed and Embase for studies of BMI and risk of PLC through November 30, 2011. Summary relative risks with their corresponding 95% confidence intervals (CIs) were calculated using a random effects model.
A total of 21 prospective studies (including 17,624 PLC cases) were included in our analysis. The summary relative risk for a 5-unit increment in BMI (in kg/m(2)) was 1.39 (95% CI: 1.25-1.55), with high heterogeneity. These positive results were robust when stratified by sex, geographic location, ascertainment of exposure and outcome, the number of cases, duration of follow-up, sample source, and cofounders. There was evidence of a nonlinear association between BMI and PLC risk, with the most pronounced increase in risk among persons with a BMI >32 kg/m(2). Patients with hepatitis C virus or cirrhosis (but not patients with hepatitis B virus) with excess weight had a higher risk of PLC development than general populations with excess weight.
Excess weight increases PLC risk. For people with HCV infection or cirrhosis, risk increases are greater than for general population.
目前对于体重指数（BMI）与原发性肝癌（PLC）风险之间的剂量反应关系、肝炎病毒感染的可能混杂作用以及性别或地理位置差异仍存在疑问。我们进行了一项荟萃分析以探讨这些问题。
我们检索了 PubMed 和 Embase 数据库，以获取截止到 2011 年 11 月 30 日有关 BMI 与 PLC 风险的前瞻性研究。使用随机效应模型计算汇总相对风险及其相应的 95%置信区间（CI）。
共纳入 21 项前瞻性研究（包括 17624 例 PLC 病例）。BMI 每增加 5 个单位（kg/m2），相对风险为 1.39（95%CI：1.25-1.55），存在高度异质性。按性别、地理位置、暴露和结局的确定、病例数、随访时间、样本来源和混杂因素进行分层后，这些阳性结果是稳健的。BMI 与 PLC 风险之间存在非线性关联，BMI>32 kg/m2 时风险增加最为显著。患有丙型肝炎病毒或肝硬化（而非乙型肝炎病毒）且超重的患者比一般超重人群更易发生 PLC。
超重会增加 PLC 的风险。对于丙型肝炎病毒感染或肝硬化患者，风险增加大于一般人群。
