Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain; Department of Clinical Oncology, Breast Cancer Unit, Hospital Universitario 12 de Octubre, Madrid, Spain; Department of Clinical Oncology, Clínica Universidad de Navarra, Pamplona, Spain.
Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain; Department of Clinical Oncology, Hospital Universitario Marqués de Valdecilla, Santander, Spain.
Prev Med. 2021 Jul;148:106535. doi: 10.1016/j.ypmed.2021.106535. Epub 2021 Mar 30.
Evidence is still limited on the influence of sedentary lifestyles on breast cancer (BC) risk. Also, prospective information on the combined effects of both sedentariness and leisure-time physical activity (LTPA) is scarce. We aimed to assess the association of higher sedentary behavior and LTPA (separately and in combination) with the risk of BC in a middle-aged cohort of university graduates. The SUN Project is a follow-up study initiated in 1999 with recruitment permanently open. Baseline assessments included a validated questionnaire on LTPA and sedentary habits. Subsequently, participants completed biennial follow-up questionnaires. Multivariable adjusted Cox models were used to estimate the hazard ratios (HR) for incident BC according to LTPA, TV-watching, the joint classification of both, and a combined 8-item multidimensional active lifestyle score. We included 10,812 women, with 11.8 years of median follow-up of. Among 115,802 women-years of follow-up, we confirmed 101 incident cases of BC. Women in the highest category of LTPA (>16.5 MET-h/week) showed a significantly lower risk of BC (HR = 0.55; 95% CI: 0.34-0.90) compared to women in the lowest category (≤6 MET/h-week). Women watching >2 h/d of TV sh owed a higher risk (HR = 1.67; 95% CI:1.03-2.72) than those who watched TV <1 h/d. Women in the highest category (6-8 points) of the multidimensional combined 8-item score showed a lower BC risk (HR = 0.35; 95% CI: 0.15-0.79) than those in the lowest category (<2 points) group. There was no significant supra-multiplicative interaction between TV-watching and LTPA. Both low LTPA and TV-watching >2 h/d may substantially increase BC risk, independently of each other.
目前关于久坐生活方式对乳腺癌（BC）风险的影响的证据仍然有限。此外，关于久坐行为和休闲时间体力活动（LTPA）两者联合影响的前瞻性信息也很缺乏。我们旨在评估在中年大学毕业生队列中，较高的久坐行为和 LTPA（单独和联合）与 BC 风险之间的关联。SUN 项目是一项始于 1999 年的随访研究，一直持续招募。基线评估包括一份关于 LTPA 和久坐习惯的经过验证的问卷。随后，参与者完成了每两年一次的随访问卷。多变量调整的 Cox 模型用于估计根据 LTPA、看电视、两者的联合分类以及综合的 8 项多维积极生活方式评分的发生 BC 的风险比（HR）。我们纳入了 10812 名女性，中位随访时间为 11.8 年。在 115802 名女性随访年中，我们确认了 101 例 BC 病例。与最低类别（≤6 MET/h 周）相比，LTPA （>16.5 MET-h/周）最高类别的女性患 BC 的风险显著降低（HR=0.55；95%CI：0.34-0.90）。每天看电视>2 小时的女性风险更高（HR=1.67；95%CI：1.03-2.72），而每天看电视<1 小时的女性风险较低。综合多维 8 项得分最高类别的女性（6-8 分）患 BC 的风险较低（HR=0.35；95%CI：0.15-0.79），而得分最低类别的女性（<2 分）风险较高。看电视和 LTPA 之间没有显著的超乘法相互作用。低 LTPA 和每天看电视>2 小时都可能独立地大大增加 BC 的风险。
