Department of Internal Medicine, University of Torino, Turin, Italy.
Diabetes Obes Metab. 2012 Jan;14(1):23-9. doi: 10.1111/j.1463-1326.2011.01480.x. Epub 2011 Nov 21.
Few studies suggest that metformin decreases cancer mortality in type-2 diabetic patients (T2DP). We explored the association between the type and duration of antidiabetic therapies and cancer and other-than-cancer mortality in a T2DP cohort, taking into account the competing risks between different causes of death and multiple potential confounding effects. The mortality rates were compared with the general population from the same area.
In 1995, all T2DP (n = 3685) at our diabetes clinic in Turin (∼12% of all T2DP in the city), without cancer at baseline, were identified. Vital status was assessed after a mean 4.5-year follow-up.
Metformin users had greater adiposity, while insulin users had more co-morbidities. All-cause- and cancer-related deaths occurred in: 9.2 and 1.6% of metformin users, 13.1 and 3.0% of sulfonylureas users and 26.8 and 4.8% of insulin users, respectively. In a Cox regression model for competing risks, adjusted for propensity score, metformin users showed a lower cancer mortality risk [hazard ratio (HR) = 0.56; 95% confidence interval (CI) 0.34-0.94], while insulin was positively associated with other-than-cancer mortality (HR = 1.56; 95%CI 1.22-1.99). Each 5-year metformin exposure was associated with a reduction in cancer death by 0.73, whereas every 5-year insulin exposure was associated with 1.25-fold increase in other-than-cancer death. Standardized mortality ratios for cancer and other-than-cancer mortality in metformin users were 43.6 (95%CI 25.8-69.0) and 99.1 (95%CI 79.3-122.5), respectively, in comparison with the general population.
Metformin users showed a lower risk of cancer-related mortality than not users or patients on diet only; this may represent another reason to choose metformin as a first-line therapy in T2DP.
很少有研究表明二甲双胍可降低 2 型糖尿病患者（T2DP）的癌症死亡率。我们在 T2DP 队列中探讨了不同类型和持续时间的抗糖尿病治疗与癌症和非癌症死亡率之间的关联，同时考虑了不同死亡原因之间的竞争风险和多种潜在混杂因素的影响。将死亡率与同一地区的一般人群进行了比较。
1995 年，我们在都灵的糖尿病诊所确定了所有 T2DP（n=3685），基线时无癌症，平均随访 4.5 年后评估了生存状态。
二甲双胍使用者的肥胖程度更高，而胰岛素使用者的合并症更多。全因和癌症相关死亡分别发生在：二甲双胍使用者中为 9.2%和 1.6%，磺脲类使用者中为 13.1%和 3.0%，胰岛素使用者中为 26.8%和 4.8%。在竞争风险的 Cox 回归模型中，经倾向评分调整后，二甲双胍使用者的癌症死亡率风险较低[风险比（HR）=0.56；95%置信区间（CI）0.34-0.94]，而胰岛素与非癌症死亡率呈正相关（HR=1.56；95%CI 1.22-1.99）。每 5 年二甲双胍暴露与癌症死亡风险降低 0.73 相关，而每 5 年胰岛素暴露与非癌症死亡风险增加 1.25 倍相关。与一般人群相比，二甲双胍使用者的癌症和非癌症死亡率标准化死亡率比分别为 43.6（95%CI 25.8-69.0）和 99.1（95%CI 79.3-122.5）。
与未使用者或仅饮食控制的患者相比，二甲双胍使用者的癌症相关死亡率风险较低；这可能是在 T2DP 中选择二甲双胍作为一线治疗的另一个原因。
