Department of Epidemiology and Biostatistics, Milken Institute School of Public Health, George Washington University, Washington, District of Columbia.
GW Cancer Center, Washington, District of Columbia.
Cancer Med. 2018 Apr;7(4):1450-1457. doi: 10.1002/cam4.1343. Epub 2018 Mar 13.
While liver cancer rates in the United States are increasing, 5-year survival is only 17.6%, underscoring the importance of prevention. Physical activity has been associated with lower risk of developing liver cancer, but most studies assess physical activity only at a single point in time, often in midlife. We utilized physical activity data from 296,661 men and women in the NIH-AARP Diet and Health Study cohort to test whether physical activity patterns over the life course could elucidate the importance of timing of physical activity on liver cancer risk. We used group modeling of longitudinal data to create physical activity trajectories using four time points across the life course from teenage years through middle age, identifying seven distinct trajectories. We then used Cox proportional hazards regression to assess the association between the physical activity trajectories and risk of hepatocellular carcinoma, the most common type of liver cancer. We found that, in adjusted analyses, compared to those with consistently low physical activity patterns, those who maintained activity levels over time had a 26-36% lower risk of liver cancer and those who increased physical activity over time had no associations with risk, while those who decreased activity over time had a nonsignificantly higher risk of liver cancer. Our results suggest that sustained physical activity is associated with lower risk of hepatocellular carcinoma, while increasing physical activity later in life may not yield the same benefit. Future research with larger sample sizes and more detailed data on dose and timing of physical activity may continue to yield insight into this association between physical activity and liver cancer risk.
尽管美国的肝癌发病率正在上升，但 5 年生存率仅为 17.6%，这突显出预防的重要性。身体活动与肝癌发病风险降低有关，但大多数研究仅在生命中的某个时刻评估身体活动，通常是在中年。我们利用 NIH-AARP 饮食与健康研究队列中 296661 名男性和女性的身体活动数据，检验生命过程中的身体活动模式是否可以阐明身体活动时间对肝癌风险的重要性。我们使用纵向数据的组建模，使用生命过程中的四个时间点（从青少年到中年）创建身体活动轨迹，确定了七种不同的轨迹。然后，我们使用 Cox 比例风险回归来评估身体活动轨迹与肝细胞癌（最常见的肝癌类型）风险之间的关联。我们发现，在调整后的分析中，与始终保持低身体活动模式的人相比，那些随着时间的推移保持活动水平的人肝癌风险降低了 26-36%，而那些随着时间的推移增加身体活动的人肝癌风险没有关联，而那些随着时间的推移减少身体活动的人肝癌风险则略有升高。我们的结果表明，持续的身体活动与较低的肝细胞癌风险相关，而晚年增加身体活动可能不会带来相同的益处。未来的研究需要更大的样本量和更详细的身体活动剂量和时间数据，可能会继续深入了解身体活动与肝癌风险之间的这种关联。
