Kasper Jocelyn S, Giovannucci Edward
Department of Nutrition, Harvard School of Public Health, Boston, MA 02115, USA.
Cancer Epidemiol Biomarkers Prev. 2006 Nov;15(11):2056-62. doi: 10.1158/1055-9965.EPI-06-0410.
Studies investigating the association between diabetes mellitus and prostate cancer have reported inconsistent findings. We examined this association by conducting a detailed meta-analysis of the studies published on the subject.
MEDLINE and EMBASE databases and bibliographies of retrieved articles were searched. Studies investigating the relationship between diabetes mellitus and prostate cancer were included in the meta-analysis. Potential sources of heterogeneity between studies were explored and publication bias was evaluated. Pooled relative risk (RR) was calculated using the random-effects model. Numerous relevant subgroup analyses were also done.
We included 19 studies, published between 1971 and 2005, in the meta-analysis and found an inverse association between diabetes mellitus and prostate cancer [RR, 0.84, 95% confidence interval (CI), 0.76-0.93, P for heterogeneity <or= 0.01]. For cohort studies alone, the RR was 0.81 (95% CI, 0.71-0.92, P for heterogeneity <or= 0.01) and for case-control studies alone, the RR was 0.89 (95% CI, 0.72-1.11, P for heterogeneity = 0.02). The significant heterogeneity was mitigated in some of the subgroup analyses. For studies conducted before prostate-specific antigen screening was introduced as a common procedure, the RR was 0.94 (95% CI, 0.85-1.03, P for heterogeneity = 0.15), and for studies conducted after this time, the RR was 0.73 (95% CI, 0.64-0.83, P for heterogeneity = 0.10). For studies that adjusted for three or more potential confounders, the RR was 0.74 (95% CI, 0.65-0.85, P for heterogeneity = 0.06) and for studies that adjusted for less than three potential confounders, the RR was 0.93 (95% CI, 0.86-1.02, P for heterogeneity = 0.18).
This study suggests an inverse relationship between diabetes and prostate cancer. Potential biological mechanisms underlying this association, as well as possible biases, are discussed.
调查糖尿病与前列腺癌之间关联的研究报告结果不一。我们通过对该主题已发表的研究进行详细的荟萃分析来研究这种关联。
检索了MEDLINE和EMBASE数据库以及检索文章的参考文献。研究糖尿病与前列腺癌之间关系的研究被纳入荟萃分析。探讨了研究之间潜在的异质性来源并评估了发表偏倚。使用随机效应模型计算合并相对风险（RR）。还进行了许多相关的亚组分析。
我们在荟萃分析中纳入了19项发表于1971年至2005年之间的研究，发现糖尿病与前列腺癌之间存在负相关[RR，0.84，95%置信区间（CI），0.76 - 0.93，异质性P≤0.01]。仅对于队列研究，RR为0.81（95%CI，0.71 - 0.92，异质性P≤0.01），仅对于病例对照研究，RR为0.89（95%CI，0.72 - 1.11，异质性P = 0.02）。在一些亚组分析中，显著的异质性有所减轻。对于在前列腺特异性抗原筛查作为常规程序引入之前进行的研究，RR为0.94（95%CI，0.85 - 1.03，异质性P = 0.15），对于在此之后进行的研究，RR为0.73（95%CI，0.64 - 0.83，异质性P = 0.10）。对于调整了三个或更多潜在混杂因素的研究，RR为0.74（95%CI，0.65 - 0.85，异质性P = 0.06），对于调整了少于三个潜在混杂因素的研究，RR为0.93（95%CI，0.86 - 1.02，异质性P = 0.18）。
本研究表明糖尿病与前列腺癌之间存在负相关。讨论了这种关联潜在的生物学机制以及可能的偏倚。
