第二型糖尿病與肝細胞癌之相關性及其人口可歸因危險比例-在病毒型肝炎高盛行地區之病例對照研究

Abstract

充分原因模式(sufficient cause model)為流行病學家Rothman 於1976 年所提出。該模式的優點在於能藉此瞭解在引發疾病的多重致病因子間的交互作用。然而在過去的文獻中，該模式在實際臨床疾病的應用並不常見。在本論文中，我們利用肝細胞癌為例，在台灣此一慢性B 型肝炎及慢性C型肝炎盛行地區中，一項以醫院為基礎的病例對照研究，利用B 型肝炎、C 型肝炎及第二型糖尿病做為肝細胞癌致病因子，探討糖尿病與肝細胞癌發生之間的相關性。由上述研究，得知糖尿病與肝細胞癌的確有相關性，特別是在此一病毒型肝炎盛行的地區，對於無C 型肝炎者，具有2.62 倍的相關性；對於B 型肝炎帶原者，或無B 型肝炎者，糖尿病與肝細胞癌間約有2 到4 倍的相關性；且糖尿病與C 型肝炎之間，對於肝細胞癌的發生，並無協同交互作用。另外，對於無B型肝炎及C 型肝炎者，糖尿病與肝細胞癌2.15 倍相關性。在經過以數量方法建構肝細胞癌的充分原因模式，以探討致病因子間的交互作用、以辨明產生肝細胞癌的致病機轉之後，可將得到的危險比例進一步據以計算每一個充分原因模式之人口可歸因比例。在台灣此一糖尿病盛行率為7%之地區，糖尿病對於肝細胞癌之人口可歸因危險比例為18.7%。並進一步援引文獻中的調整方法，以及利用貝氏之圖形迴歸模式來計算當其它干擾因子存在時，經調整之後的糖尿病的人口可歸因危險比例能更真實反應出人口可歸因危險比例，來提供制訂公共衛生政策的參考。

Among causal models, a sufficient cause-component model differs from the other models in that it provides more information on causal mechanisms and defines biologic effects of several risk factors, particularly including strengths of association and their joint interaction effects. The advantage of looking at sufficient causes for the disease of interest is to give a clue to the mechanism of disease in question. We conducted a hospital-based case-control study with the inclusion of DM as a risk factor to elucidate the causal relationship leading to HCC after controlling for other major risk factors of HCC. In this hospital-based case control study, we corroborated the association between DM and HCC in Taiwan, where viral hepatitis B and C are hyperendemic. The estimated population attributable proportion indicated that diabetes accounted for 18.7% of HCC cases given 7% prevalence of diabetes. The independent contribution to the development of HCC cases in the absence of HBV and HCV infection was around 7.5%. In addition, we applied the method from the literature to calculate the adjusted population attributable proportion. We also developed a Bayesian acyclic graphic model to calculate the adjusted PAF and 95% confidence intervals.