内容紹介
Helicobacter pylori Infection and Hyperglycemia/Diabetes Are Associated with an Increased Risk of Gastric Cancer
Summary
Although mortality rates owing to gastric cancer have gradually decreased, the morbidity rates are still high in Japan. Helicobacter pylori(H. pylori)infection is an important risk factor for gastric cancer, although most individuals with an H. pylori infection do not develop this malignancy. Therefore, it is speculated that other risk factors including lifestyle contribute to the enhanced risk of gastric cancer posed by H. pylori infection. It is also noteworthy that the prevalence of prediabetes and diabetes has dramatically increased in Japan, and cancer is now considered a possible complication of the latter. However, there have been very few epidemiological studies evaluating the relationship between diabetes and gastric cancer in Japan. The Hisayama Study, which is a prospective cohort study conducted in a Japanese community, demonstrated that the incidence of gastric cancer significantly increased with elevated fasting plasma glucose levels. A modest increase in hemoglobin A1c levels was also a significant risk factor for gastric cancer even after adjusting for other risk factors, including H. pylori infection. Moreover, among subjects who had both a high hemoglobin A1c level and H. pylori infection, the risk of gastric cancer increased synergistically. These findings suggest that even prediabetic hyperglycemia is a significant risk factor for gastric cancer in the general Japanese population. Early identification of hyperglycemia and an appropriate behavioral and therapeutic approach may help prevent gastric cancer in Japan where there is a high incidence of both this malignancy and diabetes.
要旨
わが国では胃癌の死亡率は着実に低下しているが,その罹患率は依然として高いレベルにある。Helicobacter pylori(H. pylori)感染は胃癌の最も強力な危険因子と認定されているが,感染者の多くが胃癌に罹患しないことからH. pylori感染下に胃癌発症のリスクを増大させる他の要因が存在することが示唆される。一方,わが国では生活習慣の欧米化に伴い糖尿病の有病率が急増している。糖尿病は様々な合併症を引き起こすが,近年の疫学研究の結果から癌もその一つと考えられるようになった。しかし,高血糖や糖尿病と胃癌との関係については十分な議論がなされていない。そこで福岡県久山町で継続されている胃癌の疫学調査の成績より,空腹時血糖値およびヘモグロビン(Hb)A1c値と胃癌発症との関係について H. pylori 感染を考慮して検討した。その結果,H. pylori感染を含めた胃癌の他の危険因子を調整しても,胃癌発症のハザード比は糖尿病域よりも低い血糖レベルから有意に上昇した。また,この関係は高血糖にH. pylori感染が併存することで相乗的に強くなった。胃癌の罹患率が高く糖尿病が急速に増加しているわが国では,高血糖/糖尿病の早期発見と適切な治療・管理が胃癌の予防にも有効と考えられる。
目次
Summary
Although mortality rates owing to gastric cancer have gradually decreased, the morbidity rates are still high in Japan. Helicobacter pylori(H. pylori)infection is an important risk factor for gastric cancer, although most individuals with an H. pylori infection do not develop this malignancy. Therefore, it is speculated that other risk factors including lifestyle contribute to the enhanced risk of gastric cancer posed by H. pylori infection. It is also noteworthy that the prevalence of prediabetes and diabetes has dramatically increased in Japan, and cancer is now considered a possible complication of the latter. However, there have been very few epidemiological studies evaluating the relationship between diabetes and gastric cancer in Japan. The Hisayama Study, which is a prospective cohort study conducted in a Japanese community, demonstrated that the incidence of gastric cancer significantly increased with elevated fasting plasma glucose levels. A modest increase in hemoglobin A1c levels was also a significant risk factor for gastric cancer even after adjusting for other risk factors, including H. pylori infection. Moreover, among subjects who had both a high hemoglobin A1c level and H. pylori infection, the risk of gastric cancer increased synergistically. These findings suggest that even prediabetic hyperglycemia is a significant risk factor for gastric cancer in the general Japanese population. Early identification of hyperglycemia and an appropriate behavioral and therapeutic approach may help prevent gastric cancer in Japan where there is a high incidence of both this malignancy and diabetes.
要旨
わが国では胃癌の死亡率は着実に低下しているが,その罹患率は依然として高いレベルにある。Helicobacter pylori(H. pylori)感染は胃癌の最も強力な危険因子と認定されているが,感染者の多くが胃癌に罹患しないことからH. pylori感染下に胃癌発症のリスクを増大させる他の要因が存在することが示唆される。一方,わが国では生活習慣の欧米化に伴い糖尿病の有病率が急増している。糖尿病は様々な合併症を引き起こすが,近年の疫学研究の結果から癌もその一つと考えられるようになった。しかし,高血糖や糖尿病と胃癌との関係については十分な議論がなされていない。そこで福岡県久山町で継続されている胃癌の疫学調査の成績より,空腹時血糖値およびヘモグロビン(Hb)A1c値と胃癌発症との関係について H. pylori 感染を考慮して検討した。その結果,H. pylori感染を含めた胃癌の他の危険因子を調整しても,胃癌発症のハザード比は糖尿病域よりも低い血糖レベルから有意に上昇した。また,この関係は高血糖にH. pylori感染が併存することで相乗的に強くなった。胃癌の罹患率が高く糖尿病が急速に増加しているわが国では,高血糖/糖尿病の早期発見と適切な治療・管理が胃癌の予防にも有効と考えられる。