高水平身体活动（PA）与较高的乳腺癌（BC）风险呈负相关，然而每日步数对与肥胖相关的BC生物标志物的健康益处尚不明确。我们旨在了解两年后的每日步数变化与五种与肥胖相关的BC生物标志物水平的关联。总共观察了144名非癌症妇女（年龄：47.96 ± 5.72岁）在2019年和2021年两年间的变化。在2019年（t0）和2021年（t1）之前和之后，收集了结构化问卷调查、每日步数和空腹血样本。通过ELISA测定了生物标志物（IGF结合蛋白3、脂联素、可溶性瘦素受体、C-反应蛋白和抵抗素）的水平。参与者被分为持续低步数、减少步数、增加步数和持续高步数四组。采用线性回归模型估计不同组别与提出的生物标志物的关联，以持续低步数为参考。通过混合线性模型量化了每日步数的时间变化与生物标志物之间的关联。与持续低步数相比，增加步数与C-反应蛋白水平降低相关（β=-0.74，95%CI=-1.23--0.26，P值=2.98 × 10-3）。发现了时间变化的步数与C-反应蛋白水平呈负相关，这一结果在不同的肥胖类型和基线步数水平组别中保持一致。未观察到每日步数与其他蛋白质的相关性。

While a higher level of physical activity (PA) is inversely associated with a higher breast cancer (BC) risk, the health benefits of daily steps on obesity-related BC biomarkers remain unclear. We aimed to understand the associations of changes in step counts with levels of five obesity-related BC biomarkers during a two-year follow-up. In total, 144 non-cancer women (47.96 ± 5.72) were observed on both 2019 and 2021. A structured questionnaire, daily steps and fasting blood samples were collected before (t0, 2019) and after (t1, 2021). Levels of biomarkers (IGF-binding proteins 3, adiponectin, soluble leptin receptor, C-reactive protein, and resistin) were assayed by ELISA. Participants were divided into persistent low steps, decreasing steps, increasing steps, and persistent high steps. Associations of categories on proposed biomarkers were estimated using linear regression models, with persistent low steps as reference. Associations between time-varying step counts with biomarkers were quantified using mixed linear models. Compared with persistent low steps, increasing steps is associated with a reduction in C-reactive protein level (β=-0.74, 95%CI=-1.23--0.26, P-value = 2.98 × 10-3). An inverse association between time-varying step counts with C-reactive protein level was identified, consistent across different obesity types and baseline step level categories. No association with daily step counts was observed for other proteins.