PDF(Pubmed)
Abstract：
Body fatness is considered a probable risk factor for biliary tract cancer (BTC), whereas cholelithiasis is an established factor. Nevertheless, although obesity is an established risk factor for cholelithiasis, previous studies of the association of body mass index (BMI) and BTC did not take the effect of cholelithiasis fully into account. To better understand the effect of BMI on BTC, we conducted a pooled analysis using population-based cohort studies in Asians. In total, 905 530 subjects from 21 cohort studies participating in the Asia Cohort Consortium were included. BMI was categorized into four groups: underweight (<18.5 kg/m2 ); normal (18.5-22.9 kg/m2 ); overweight (23-24.9 kg/m2 ); and obese (25+ kg/m2 ). The association between BMI and BTC incidence and mortality was assessed using hazard ratios (HR) and 95% confidence intervals (CIs) by Cox regression models with shared frailty. Mediation analysis was used to decompose the association into a direct and an indirect (mediated) effect. Compared to normal BMI, high BMI was associated with BTC mortality (HR 1.19 [CI 1.02-1.38] for males, HR 1.30 [1.14-1.49] for females). Cholelithiasis had significant interaction with BMI on BTC risk. BMI was associated with BTC risk directly and through cholelithiasis in females, whereas the association was unclear in males. When cholelithiasis was present, BMI was not associated with BTC death in either males or females. BMI was associated with BTC death among females without cholelithiasis. This study suggests BMI is associated with BTC mortality in Asians. Cholelithiasis appears to contribute to the association; and moreover, obesity appears to increase BTC risk without cholelithiasis.
摘要：
身体肥胖被认为是胆道癌（BTC）的可能危险因素，而胆石症是一个既定的因素。然而，虽然肥胖是胆石症的既定危险因素，以往关于体重指数(BMI)和BTC相关性的研究未充分考虑胆石症的影响.为了更好地了解BMI对BTC的影响，我们使用基于人群的亚洲人群队列研究进行了汇总分析.总的来说,参与亚洲队列联盟的21项队列研究的90530名受试者被纳入。BMI分为四组：体重不足（<18.5kg/m2）；正常（18.5-22.9kg/m2）；超重（23-24.9kg/m2）；和肥胖（25kg/m2）。使用风险比（HR）和95％置信区间（CIs）通过具有共同虚弱的Cox回归模型评估BMI与BTC发病率和死亡率之间的关联。中介分析用于将关联分解为直接和间接(介导的)效应。与正常BMI相比，高BMI与BTC死亡率相关(男性的HR1.19[CI1.02-1.38]，女性的HR1.30[1.14-1.49]）。胆石症与BMI对BTC风险有显著的交互作用。BMI与BTC风险直接相关，并通过女性胆石症，而男性的关联尚不清楚。当胆石症出现时，BMI与男性或女性的BTC死亡无关。在没有胆石症的女性中，BMI与BTC死亡相关。这项研究表明，BMI与亚洲人的BTC死亡率有关。胆结石似乎有助于这种关联；此外，如果没有胆石症，肥胖似乎会增加BTC的风险。
