Koebnick Corinna, Michaud Dominique, Moore Steven C, Park Yikyung, Hollenbeck Albert, Ballard-Barbash Rachel, Schatzkin Arthur, Leitzmann Michael F
Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Department of Health and Human Services, Bethesda, Maryland, USA.
Cancer Epidemiol Biomarkers Prev. 2008 May;17(5):1214-21. doi: 10.1158/1055-9965.EPI-08-0026.
Increased body size and lack of physical activity are associated with increased risk of several cancers, but the relations of body mass index (BMI) and physical activity to bladder cancer are poorly understood. We investigated the associations between BMI, physical activity, and bladder cancer in the NIH-AARP Diet and Health Study, a prospective cohort of 471,760 U.S. men and women, followed from 1995 to 2003. During 3,404,642 person-years of follow-up, we documented 1,719 incident cases of bladder cancer. Compared with normal weight, obesity was associated with an up to 28% increased risk for bladder cancer. The multivariate relative risks of bladder cancer for BMI values of 18.5 to 24.9 (reference), 25.0 to 29.9, 30.0 to 34.9, and >or=35 kg/m2 were 1.0, 1.15, 1.22, and 1.28 (95% confidence interval, 1.02-1.61; P trend = 0.028). The association between BMI and bladder cancer was consistent among subgroups defined by gender, education, smoking status, and other potential effect modifiers. In contrast, physical activity showed no statistically significant relation with bladder cancer. After multivariate adjustment, including BMI, the relative risks of bladder cancer for increasing frequency of physical activity [0 (reference), <1, 1-2, 3-4, and >or=5 times a week] were 1.0, 0.85, 0.89, 0.91, and 0.87 (95% confidence interval, 0.74-1.02; P trend = 0.358), respectively. In conclusion, these findings provide support for a modest adverse effect of adiposity on risk for bladder cancer. In contrast, our results do not suggest a relation between physical activity and bladder cancer.
体型增大和缺乏身体活动与多种癌症风险增加相关，但体重指数（BMI）和身体活动与膀胱癌之间的关系却知之甚少。我们在NIH-AARP饮食与健康研究中调查了BMI、身体活动与膀胱癌之间的关联，该研究是一项对471,760名美国男性和女性进行的前瞻性队列研究，随访时间从1995年至2003年。在3,404,642人年的随访期间，我们记录了1,719例膀胱癌新发病例。与正常体重相比，肥胖与膀胱癌风险增加高达28%相关。BMI值为18.5至24.9（参照）、25.0至29.9、30.0至34.9以及≥35 kg/m²时，膀胱癌的多变量相对风险分别为1.0、1.15、1.22和1.28（95%置信区间，1.02 - 1.61；P趋势 = 0.028）。在按性别、教育程度、吸烟状况和其他潜在效应修饰因素定义的亚组中，BMI与膀胱癌之间的关联是一致的。相比之下，身体活动与膀胱癌未显示出统计学上的显著关联。在进行包括BMI在内的多变量调整后，身体活动频率增加[0（参照）、<1、1 - 2、3 - 4以及≥5次/周]时，膀胱癌的相对风险分别为1.0、0.85、0.89、0.91和0.87（95%置信区间，0.74 - 1.02；P趋势 = 0.358）。总之，这些发现支持肥胖对膀胱癌风险有适度的不利影响。相比之下，我们的结果并未表明身体活动与膀胱癌之间存在关联。
