A Cohort Study on the Association of Impaired Glucose Tolerance with Cancer Risk in 2 Towns of Hokkaido

目的：通过队列研究，我们评估了葡萄糖耐量降低（RGT）与癌症发生之间的关系。方法：1977年和1978年分别从日本北海道的Tanno和Sohbetsu镇随机选择了1989人（男性908人，女性1,081人），年龄在40 ~ 64岁之间。对研究受试者进行血清中总蛋白、白蛋白、尿酸、总胆固醇、β-脂蛋白和甘油三酯的测量以及50 g口服葡萄糖耐量试验。他们被跟踪到2002年底，590人（30.0%）的研究对象，谁参加了大规模筛查计划在2001年7月，进行了采访，以获得他们的过去的历史。采用考克斯比例风险模型估计风险比（HR）及其95%置信区间（95%CI）。在随访期间，145例受试者（94例男性和51例女性）报告患有癌症。我们分析的数据不包括任何人已经观察了不到5年，因为基线survey.Results：结果，年龄调整的HR患癌症显着增加超过四分位数的血糖在120分钟后，50克口服葡萄糖负荷的男性受试者（p趋势，p=0.039）。这一结果是没有实质性的修改，即使调整吸烟和饮酒的习惯，除了年龄（p的趋势，p=0.044）。结论：RGT和癌症的风险增加之间的关系可能是病因与几种可能的解释的生物学机制。如果是这样的话，有人建议，防止葡萄糖耐量受损或降低可能对降低癌症风险很重要。需要进一步研究来评估其他可能的因素与GTR一起工作的作用，例如增加能量摄入和减少体力活动。

Purpose : By means of a cohort study, we evaluated the association between reduced glucose tolerance (RGT) and the occurrence of cancer.Methods : A thousand nine hundred and eighty nine persons (908 males and 1,081 females) aged from 40 to 64 years from towns of Tanno and Sohbetsu in Hokkaido, Japan were randomly selected as the subjects of this study in 1977 and 1978, respectively. Measurements of total protein, albumin, uric acid, total cholesterol, β-lipoprotein, and trigliceride in serum as well as 50g oral glucose tolerance test were performed for the study subjects. They were followed-up until the end of 2002, and 590 persons (30.0%) among the study subjects, who attended mass-screening programs in July of 2001, were interviewed to obtain their past history. Hazard ratios (HRs) and their 95% confidence intervals (95%CIs) were estimated by Cox's proportional hazard model. In the follow-up period, 145 subjects (94 males and 51 females) were reported to have cancer. We analyzed the data not including any who had been observed for less than 5 years since the baseline survey.Results : As a result, the age-adjusted HR for having cancer was significantly increased over quartiles of plasma glucose at 120 minutes after a 50g oral glucose load in the male subjects (p for trend, p=0.039). This result was not substantially modified even after adjusting for habits of smoking and drinking in addition to age (p for trend, p=0.044).Conclusion : The relationship between RGT and increased risk of cancer may be etiological with several possible explanations for the biological mechanism. If so, it has been suggested that protection from impaired or reduced glucose tolerance may be important for reducing the risk of cancer. Further studies are necessary to evaluate the role of other possible factors working in conjunction with GTR such as increased energy intake and decreased physical activities.