Rosenberg Lynn, Boggs Deborah, Wise Lauren A, Palmer Julie R, Roltsch Mark H, Makambi Kepher H, Adams-Campbell Lucile L
Slone Epidemiology Center, Boston University, 1010 Commonwealth Avenue, Boston, MA 02215, USA.
Cancer Epidemiol Biomarkers Prev. 2006 Aug;15(8):1438-42. doi: 10.1158/1055-9965.EPI-06-0079.
Physical activity is associated with a reduced risk of colon cancer, but the effect of activity on colorectal adenomas, which are precursors to colon cancer, is uncertain. The influence of physical activity on colorectal adenomas among African-American women is of particular interest because African-American women have an increased risk of colon cancer relative to other U.S. women.
We prospectively assessed the relation of physical activity to the incidence of colorectal polyps among African-American women. We followed 45,400 women in the Black Women's Health Study from 1997 to 2003. Data were obtained by biennial mailed questionnaires. During 287,029 person-years of follow-up, 1,390 women reported having been diagnosed with colorectal polyps. A review of medical records of 58 women who reported colorectal polyps indicated that 59% had adenomas and 41% had hyperplastic polyps. We converted hours per week of vigorous exercise and hours per week of walking to metabolic equivalent (MET)-hours. We estimated incidence rate ratios with Cox proportional hazard models, controlling for age, body mass index, smoking, family history of colorectal cancer, and education.
For total MET-hours/wk spent in walking and vigorous exercise, the incidence rate ratio decreased from 0.94 for <5 MET-hours/wk to 0.72 for >or=40 MET-hours/wk (P(trend) = 0.01). The inverse association was apparent among most subgroups examined, including women who may be at higher risk of colorectal adenomas because of being obese.
Increased physical activity is associated with a reduced incidence of colorectal polyps among African-American women.
体力活动与结肠癌风险降低相关，但体力活动对作为结肠癌前体的结直肠腺瘤的影响尚不确定。体力活动对非裔美国女性结直肠腺瘤的影响尤为令人关注，因为与其他美国女性相比，非裔美国女性患结肠癌的风险更高。
我们前瞻性评估了体力活动与非裔美国女性结直肠息肉发病率之间的关系。1997年至2003年，我们对黑人女性健康研究中的45400名女性进行了随访。数据通过每两年邮寄一次的问卷获得。在287029人年的随访期间，1390名女性报告被诊断患有结直肠息肉。对58名报告患有结直肠息肉的女性的病历审查表明，59%患有腺瘤，41%患有增生性息肉。我们将每周剧烈运动的小时数和每周步行的小时数换算为代谢当量（MET）小时。我们使用Cox比例风险模型估计发病率比，并控制年龄、体重指数、吸烟、结直肠癌家族史和教育程度。
对于每周步行和剧烈运动所花费的总MET小时数，发病率比从每周<5 MET小时的0.94降至每周≥40 MET小时的0.72（P趋势=0.01）。在大多数研究亚组中，这种负相关关系都很明显，包括因肥胖可能患结直肠腺瘤风险较高的女性。
体力活动增加与非裔美国女性结直肠息肉发病率降低相关。
