Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, USA.
Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, USA.
Ann Oncol. 2021 Jun;32(6):778-786. doi: 10.1016/j.annonc.2021.03.200. Epub 2021 Apr 1.
Although colorectal cancer (CRC) incidence in the USA is declining overall, its incidence is increasing among those younger than 50 years of age. The reasons underlying the increasing trend are largely unknown, although behavioral changes, such as unhealthy diet and lifestyle factors, may be partially responsible.
A prospective cohort study included 94 217 women aged 26-45 years at baseline. Validated anthropometric measures and lifestyle information were self-reported biennially. Exposures were four recommendation-based dietary indices-the prime diet quality score and three plant-based dietary indices; and two mechanism-based indices-the empirical dietary and lifestyle index for hyperinsulinemia (EDIH and ELIH). We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for overall CRC and for early-onset (before age 50) and after age 50 CRC separately.
We documented 332 cases of CRC during 24 years of follow-up (2 113 655 person-years), with an average age of 52 ± 7 years at diagnosis. Hyperinsulinemic dietary and lifestyle patterns were associated with a higher risk of CRC. Multivariable-adjusted HRs (95% CIs) comparing participants in the highest versus lowest quartile were: 1.67 for EDIH (95% CI: 1.15-2.44, P-trend = 0.01) and 1.51 for ELIH (95% CI: 1.10-2.08, P-trend = 0.01). Moreover, per 75% increment in rank, ELIH appeared to be a stronger risk factor for early-onset CRC (HR = 1.86, 95% CI: 1.12-3.07) than after age 50 CRC (HR = 1.20, 95% CI: 0.83-1.73, P-heterogeneity = 0.16). The four recommendation-based indices were not significantly associated with overall, early-onset, or after age 50 CRC risk (per 75% increment in rank, HRs ranged from 0.75 to 1.28).
Dietary and lifestyle patterns contributing to hyperinsulinemia were associated with greater CRC risk in younger women. Moreover, the hyperinsulinemic lifestyle showed a suggestively stronger positive association with early-onset CRC risk, compared with after age 50 CRC. Our findings suggest that dietary and lifestyle interventions to reduce insulinemic potential may be effective for CRC prevention among younger women.
尽管美国的结直肠癌（CRC）发病率总体呈下降趋势，但在 50 岁以下人群中的发病率却在上升。这种上升趋势的原因尚不清楚，尽管行为改变，如不健康的饮食和生活方式因素，可能在一定程度上起作用。
一项前瞻性队列研究纳入了 94217 名基线时年龄在 26-45 岁的女性。每两年通过自我报告的方式收集经过验证的人体测量指标和生活方式信息。暴露因素包括四个基于推荐的饮食指数——主要饮食质量评分和三个基于植物的饮食指数；以及两个基于机制的指数——经验性饮食和高胰岛素血症生活方式指数（EDIH 和 ELIH）。我们计算了总体 CRC 以及早发性（50 岁前）和 50 岁后 CRC 的风险比（HRs）和 95%置信区间（CIs）。
在 24 年的随访期间，我们记录了 332 例 CRC（2113655 人年），诊断时的平均年龄为 52±7 岁。高胰岛素血症的饮食和生活方式与 CRC 风险增加有关。多变量调整后的 HRs（95%CI）比较了四分位数中最高与最低的参与者：EDIH 为 1.67（95%CI：1.15-2.44，P-趋势=0.01），ELIH 为 1.51（95%CI：1.10-2.08，P-趋势=0.01）。此外，ELIH 的排名每增加 75%，似乎是早发性 CRC（HR=1.86，95%CI：1.12-3.07）的更强风险因素，而不是 50 岁后 CRC（HR=1.20，95%CI：0.83-1.73，P 异质性=0.16）。四个基于推荐的指数与总体、早发性或 50 岁后 CRC 风险无显著相关性（每增加 75%的排名，HRs 范围为 0.75 至 1.28）。
导致高胰岛素血症的饮食和生活方式与年轻女性 CRC 风险增加有关。此外，与 50 岁后 CRC 相比，高胰岛素血症的生活方式与早发性 CRC 风险呈更强的正相关。我们的研究结果表明，减少胰岛素生成潜力的饮食和生活方式干预可能对年轻女性的 CRC 预防有效。
