Sprague Brian L, Trentham-Dietz Amy, Klein Barbara E K, Klein Ronald, Cruickshanks Karen J, Lee Kristine E, Hampton John M
Departments of Population Health Sciences, University of Wisconsin, 610 Walnut Street, Madison WI 53726, USA.
Cancer Epidemiol Biomarkers Prev. 2008 Oct;17(10):2714-22. doi: 10.1158/1055-9965.EPI-08-0042.
Previous studies have suggested that physical activity may lower lung cancer risk. The association of physical activity with reduced chronic inflammation provides a potential mechanism, yet few studies have directly related inflammatory markers to cancer incidence. The relation among physical activity, inflammation, and lung cancer risk was evaluated in a prospective cohort of 4,831 subjects, 43 to 86 years of age, in Beaver Dam, Wisconsin. A total physical activity index was created by summing up kilocalories per week from sweat-inducing physical activities, city blocks walked, and flights of stairs climbed. Two inflammatory markers, WBC count and serum albumin, were measured at the baseline examination. During an average of 12.8 years of follow-up, 134 incident cases of lung cancer were diagnosed. After multivariable adjustment, participants in the highest tertile of total physical activity index had a 45% reduction in lung cancer risk compared with those in the lowest tertile (hazard ratio, 0.55; 95% confidence interval, 0.35-0.86). Participants with WBC counts in the upper tertile (>or=8 x 10(3)/microL) were 2.81 (95% confidence interval, 1.58-5.01) times as likely to develop lung cancer as those with counts in the lowest tertile (<6.4 x 10(3)/microL). Serum albumin was not related to lung cancer risk. There was no evidence that inflammation mediated the association between physical activity and lung cancer risk, as the physical activity risk estimates were essentially unchanged after adjustment for WBC count. Although the potential for residual confounding by smoking could not be eliminated, these data suggest that physical activity and WBC count are independent risk factors for lung cancer.
以往的研究表明，体育活动可能会降低肺癌风险。体育活动与慢性炎症减轻之间的关联提供了一种潜在机制，但很少有研究直接将炎症标志物与癌症发病率联系起来。在威斯康星州比弗代尔姆的一个由4831名43至86岁受试者组成的前瞻性队列中，评估了体育活动、炎症与肺癌风险之间的关系。通过汇总每周因出汗的体育活动、步行的城市街区数和攀爬的楼梯层数所消耗的千卡数，创建了一个总体育活动指数。在基线检查时测量了两种炎症标志物，即白细胞计数和血清白蛋白。在平均12.8年的随访期间，诊断出134例肺癌新发病例。经过多变量调整后，总体育活动指数处于最高三分位数的参与者与处于最低三分位数的参与者相比，肺癌风险降低了45%（风险比，0.55；95%置信区间，0.35 - 0.86）。白细胞计数处于上三分位数（≥8×10³/微升）的参与者患肺癌的可能性是处于最低三分位数（<6.4×10³/微升）参与者的2.81倍（95%置信区间，1.58 - 5.01）。血清白蛋白与肺癌风险无关。没有证据表明炎症介导了体育活动与肺癌风险之间的关联，因为在调整白细胞计数后，体育活动风险估计值基本未变。尽管吸烟导致残余混杂的可能性无法消除，但这些数据表明体育活动和白细胞计数是肺癌的独立危险因素。
