Duke University School of Medicine, Durham, NC, USA.
Prostate Cancer Prostatic Dis. 2011 Dec;14(4):326-31. doi: 10.1038/pcan.2011.28. Epub 2011 Jun 28.
Men with diabetes mellitus are less likely to be diagnosed with prostate cancer (PCa). As diabetic men have lower serum PSA, it is unclear if this is due to lower PCa incidence or reflects detection bias from fewer PSA-triggered biopsies. To account for differential biopsy rates, we used multivariate regression to examine the link between diabetes and PCa risk in the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial, which required all subjects to undergo biopsy regardless of PSA. We further tested for interaction between diabetes and obesity. Diabetes status and body mass index (BMI) measurements were obtained at baseline. On multivariate analysis, diabetes was not associated with PCa risk (odds ratio (OR) 1.01, 95% confidence interval 0.79-1.30, P=0.92) or risk of low- or high-grade disease (all P ≥ 0.65). When stratified by obesity, diabetes was also not associated with PCa risk in any BMI category (all P ≥ 0.15). However, there was suggestion of effect modification by obesity for high-grade disease (P-interaction=0.053). Specifically, diabetes was associated with decreased risk of high-grade PCa in normal-weight men but increased risk in obese men (OR 0.35 vs 1.38). In the REDUCE trial, when all men underwent biopsy, diabetes was not associated with lower PCa risk, but rather equal risk of PCa, low-grade PCa and high-grade PCa.
患有糖尿病的男性被诊断出患有前列腺癌（PCa）的可能性较低。由于糖尿病男性的血清 PSA 较低，目前尚不清楚这是由于 PCa 发病率较低，还是反映了由于较少的 PSA 触发活检而导致的检测偏差。为了说明差异活检率，我们使用多变量回归来检查 REDUCE 试验中糖尿病与 PCa 风险之间的联系，该试验要求所有受试者进行活检，无论 PSA 如何。我们进一步测试了糖尿病和肥胖之间的相互作用。糖尿病状况和体重指数（BMI）测量值在基线时获得。在多变量分析中，糖尿病与 PCa 风险（比值比（OR）1.01，95％置信区间 0.79-1.30，P=0.92）或低级别或高级别疾病的风险无关（所有 P≥0.65）。按肥胖分层时，糖尿病在任何 BMI 类别中也与 PCa 风险无关（所有 P≥0.15）。但是，肥胖对高级别疾病的影响修饰存在提示（P 交互=0.053）。具体来说，在正常体重的男性中，糖尿病与高级别 PCa 的风险降低有关，但在肥胖男性中则与风险增加有关（OR 0.35 与 1.38）。在 REDUCE 试验中，当所有男性都进行了活检时，糖尿病与较低的 PCa 风险无关，而是与 PCa、低级别 PCa 和高级别 PCa 的风险相等。
