Unit for Cardiovascular Epidemiology, The Gertner Institute for Epidemiology and Health Policy Research, Sheba Medical Center, Tel Hashomer, 52621, Israel.
BMC Cancer. 2012 Aug 23;12:364. doi: 10.1186/1471-2407-12-364.
Both diabetes and glucose-lowering medications have been associated with an increased risk of cancer incidence. This study will compare cancer incidence rates in individuals with and without diabetes; and will investigate, in individuals with diabetes, an association between glucose control and cancer incidence; and between the use of specific glucose-lowering medications, as well as no drug exposure, and cancer incidence.
METHODS/DESIGN: This is a population based historical cohort study of all individuals aged 21 years or older (about 2,300,000) who were insured by Clalit Health Services, the largest health maintenance organization in Israel during a ten-year study period. Four study groups will be established according to the status of diabetes and cancer at study entry, Jan 1, 2002: cancer free, diabetes free; cancer free, diabetes prevalent; cancer prevalent, diabetes free; and cancer prevalent, diabetes prevalent. Individuals without diabetes at study entry will be followed for diabetes incidence, and all four groups will be followed for specific cancer incidence, including second primary neoplasms. Glucose control will be assessed by HbA1c and by fasting plasma glucose levels. Time dependent regression models for cancer incidence will account for glucose-lowering medications as they are added and changed over the follow-up period. A large number of demographic and clinical variables will be considered, including: age, gender, BMI, smoking status, concomitant medications, glucose control (assessed by HbA1c and by fasting plasma glucose) and cancer screening tests.
Strengths of this study include the large population; high quality comprehensive data; comparison to individuals without diabetes, and to those with diabetes but not treated with glucose-lowering medications; and the extensive range of variables available for analysis. The great increases in diabetes prevalence and in treatment options render this study particularly relevant and timely. The Israeli national healthcare system, characterized by high standard and uniform healthcare, offers an advantageous environment for its conduct.
糖尿病和降糖药物的使用均与癌症发病率的增加相关。本研究将比较有或无糖尿病患者的癌症发病率；并在糖尿病患者中，调查血糖控制与癌症发病率之间的关系；以及特定降糖药物的使用与无药物暴露与癌症发病率之间的关系。
方法/设计：这是一项基于人群的历史队列研究，纳入了在 2002 年 1 月 1 日期间，以色列最大的医疗保健组织 Clalit 健康服务的所有 21 岁或以上（约 230 万）参保个体。根据研究开始时的糖尿病和癌症状态，将建立四个研究组：无癌症、无糖尿病；无癌症、糖尿病流行；有癌症、无糖尿病；有癌症、糖尿病流行。在研究开始时无糖尿病的个体将随访糖尿病发病率，所有四个组都将随访特定癌症发病率，包括第二原发肿瘤。血糖控制将通过 HbA1c 和空腹血浆葡萄糖水平进行评估。癌症发病率的时间依赖性回归模型将考虑随着随访期间降糖药物的添加和改变而进行的调整。将考虑大量的人口统计学和临床变量，包括：年龄、性别、BMI、吸烟状况、合并用药、血糖控制（通过 HbA1c 和空腹血浆葡萄糖评估）和癌症筛查试验。
本研究的优势包括：人群庞大；高质量的综合数据；与无糖尿病个体以及未接受降糖药物治疗的糖尿病个体进行比较；以及可用于分析的大量变量。糖尿病患病率和治疗选择的大幅增加使得本研究特别相关和及时。以色列国家医疗保健系统以高标准和统一的医疗保健为特点，为其开展提供了有利的环境。
