Mounting evidence indicates a potential beneficial effect of vigorous-intensity physical activity on hepatocellular carcinoma (HCC). However, the association between moderate-intensity physical activity, such as brisk walking, and the risk of HCC remains largely unknown. Two prospective cohorts of 77,535 women from the Nurses' Health Study and 44,540 men from the Health Professionals Follow-up Study were included. Weekly time spent on physical activities were updated biennially. The Cox proportional hazard regression model was used to calculate multivariable hazard ratios (HR) and 95% confidence intervals (95% CI). After an average 23-year follow-up, we identified 138 incident HCC cases. A higher amount of total physical activity was not significantly associated with a reduced risk of HCC (top tertile vs. bottom tertile; HR = 0.78; 95% CI, 0.51–1.18; Ptrend = 0.33). For the same comparison, there was an inverse association between moderate-intensity activity and HCC risk (HR = 0.60; 95% CI, 0.38–0.94; Ptrend = 0.04), whereas no statistically significant association with vigorous-intensity activity (HR = 0.88; 95% CI, 0.56–1.37; Ptrend = 0.74). Engaging in brisk walking was significantly associated with a lower risk of HCC (over 1 hour/week vs. non-brisk walking; HR = 0.50; 95% CI, 0.31–0.78; Ptrend = 0.006). The association between brisk walking and HCC risk was generally present across all subgroups, including age, body mass index, type 2 diabetes mellitus, smoking status, aspirin use, and alcohol consumption (all Pinteraction ≥ 0.05). In conclusion, moderate-intensity activity, especially brisk walking, was associated with reduced risk of HCC among U.S. men and women. If confirmed, brisk walking might serve a feasible way for HCC prevention.

中文翻译：

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美国男性和女性的体力活动和肝细胞癌风险

越来越多的证据表明，剧烈强度的体育活动对肝细胞癌 (HCC) 具有潜在的有益影响。然而，中等强度的体力活动（如快走）与 HCC 风险之间的关联在很大程度上仍然未知。包括来自护士健康研究的 77,535 名女性和来自卫生专业人员后续研究的 44,540 名男性的两个前瞻性队列。每周花在体育活动上的时间每两年更新一次。Cox 比例风险回归模型用于计算多变量风险比 (HR) 和 95% 置信区间 (95% CI)。经过平均 23 年的随访，我们确定了 138 例 HCC 病例。较高的总体力活动量与 HCC 风险降低没有显着相关性（顶部三分位与底部三分位；HR = 0.78；95% CI，0。51–1.18；趋势 = 0.33)。对于相同的比较，中等强度活动与 HCC 风险之间存在负相关（HR = 0.60；95% CI，0.38–0.94；Ptrend = 0.04），而与高强度活动没有统计学显着相关性（HR = 0.88 ；95% CI，0.56–1.37；Ptrend = 0.74）。快走与较低的 HCC 风险显着相关（每周超过 1 小时与非快走相比；HR = 0.50；95% CI，0.31–0.78；Ptrend = 0.006）。快走与 HCC 风险之间的关联普遍存在于所有亚组中，包括年龄、体重指数、2 型糖尿病、吸烟状况、阿司匹林使用和饮酒（所有 Pinteraction ≥ 0.05）。总之，中等强度的活动，尤其是快走，与美国男性和女性患 HCC 的风险降低有关。如果确认，