Association of Obesity With Risk of Early-Onset Colorectal Cancer Among Women
Association of Obesity With Risk of Early-Onset Colorectal Cancer Among Women
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DOI：
10.1001/jamaoncol.2018.4280
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发表时间：
2019-01-01
期刊：
影响因子：
28.4
通讯作者：
Cao, Yin
中科院分区：
文献类型：
--
作者：
Liu, Po-Hong;Wu, Kana;Cao, Yin
结直肠癌（CRC）的发病率和死亡率在50岁以下的个体（早发性CRC）正在增加。这种增长的原因在很大程度上是未知的，尽管肥胖的日益流行可能是部分原因。目的前瞻性研究成年早期肥胖和体重增加与早发性结直肠癌风险之间的关系。设计、环境和参与者护士健康研究II是一项前瞻性、正在进行的队列研究，研究入组时年龄在25至42岁之间的美国女护士（1989年）。在入组时，共有85256名无癌症和炎症性肠病的女性被纳入该分析，随访至2011年12月31日。经过验证的拟人化测量和生活方式信息每两年自我报告一次。统计分析时间为2017年6月12日至2018年6月28日。目前的身体质量指数（BMI）（以体重（公斤）除以身高（米）的平方计算），18岁时的身体质量指数，以及18岁以来的体重增加。发生早发性CRC的相对危险度（RR）。结果在85256名被研究的女性中，在1 196452人年的随访中，记录了114例早发性CRC（诊断时中位年龄45岁；四分位数范围41-47岁）。与BMI为18.5 ~ 22.9的女性相比，超重女性（BMI为25.0 ~ 29.9）的多变量RR为1.37 (95% CI, 0.81 ~ 2.30)，肥胖女性（BMI为30.0）的多变量RR为1.93 （95% CI, 1.15 ~ 3.25）。BMI每增加5个单位的RR为1.20 （95% CI, 1.05-1.38；趋势P = 0.01）。在过去10年内没有结直肠癌家族史和没有下内镜检查的女性中也观察到类似的关联。18岁时的身体质量指数和18岁以后的体重增加都促成了这一观察结果。与18岁时BMI为18.5至20.9的女性相比，BMI为21.0至22.9的女性早发性CRC的RR为1.32 (95% CI, 0.80-2.16)，而18岁时BMI为23.0或更高的女性的RR为1.63 (95% CI, 1.01-2.61) （P = 0.66）。与体重增加小于5.0 kg或体重减轻的女性相比，体重增加20.0至39.9 kg的女性早发性CRC的RR为1.65 (95% CI, 0.96-2.81)，体重增加40.0 kg或以上的女性早发性CRC的RR为2.15 (95% CI, 1.01-4.55)（趋势P = 0.007）。结论和相关性肥胖与女性早发性结直肠癌风险增加相关。进一步的男性调查和阐明潜在的生物学机制是必要的。
IMPORTANCE Colorectal cancer (CRC) incidence and mortality among individuals younger than 50 years (early-onset CRC) are increasing. The reasons for such increases are largely unknown, although the increasing prevalence of obesity may be partially responsible.OBJECTIVE To investigate prospectively the association between obesity and weight gain since early adulthood with the risk of early-onset CRC.DESIGN, SETTING, AND PARTICIPANTS The Nurses' Health Study II is a prospective, ongoing cohort study of US female nurses aged 25 to 42 years at study enrollment (1989). A total of 85 256 women free of cancer and inflammatory bowel disease at enrollment were included in this analysis, with follow-up through December 31, 2011. Validated anthropomorphic measures and lifestyle information were self-reported biennially. Statistical analysis was performed from June 12, 2017, to June 28, 2018.EXPOSURES Current body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared), BMI at 18 years of age, and weight gain since 18 years of age.MAIN OUTCOMES AND MEASURES Relative risk (RR) for incident early-onset CRC.RESULTS Among the 85 256 women studied, 114 cases of early-onset CRC were documented (median age at diagnosis, 45 years; interquartile range, 41-47 years) during 1 196 452 person-years of follow-up. Compared with women with a BMI of 18.5 to 22.9, the multivariable RR was 1.37 (95% CI, 0.81-2.30) for overweight women (BMI, 25.0-29.9) and 1.93 (95% CI, 1.15-3.25) for obese women (BMI, >= 30.0). The RR for each 5-unit increment in BMI was 1.20 (95% CI, 1.05-1.38; P = .01 for trend). Similar associations were observed among women without a family history of CRC and without lower endoscopy within the past 10 years. Both BMI at 18 years of age and weight gain since 18 years of age contributed to this observation. Compared with women with a BMI of 18.5 to 20.9 at 18 years of age, the RR of early-onset CRC was 1.32 (95% CI, 0.80-2.16) for women with a BMI of 21.0 to 22.9 and 1.63 (95% CI, 1.01-2.61) for women with a BMI of 23.0 or greater at 18 years of age (P = .66 for trend). Compared with women who had gained less than 5.0 kg or had lost weight, the RR of early-onset CRC was 1.65 (95% CI, 0.96-2.81) for women gaining 20.0 to 39.9 kg and 2.15 (95% CI, 1.01-4.55) for women gaining 40.0 kg or more (P = .007 for trend).CONCLUSIONS AND RELEVANCE Obesity was associated with an increased risk of early-onset CRC among women. Further investigations among men and to elucidate the underlying biological mechanisms are warranted.