背景:肥胖可能通过炎症增加的机制增加结直肠癌(CRC)的风险。虽然BMI是最常用的肥胖指标,它可能不太准确地测量黑人人群的肥胖。在这里,我们调查BMI,低白蛋白作为炎症生物标志物,和CRC风险在种族不同的队列中。
方法:参与者数据来自南方社区队列研究的71,141名参与者,包括724起CRC事件。在队列中,69%是黑色。血清白蛋白浓度,从登记时采集的样本中,235例和567例对照。按年龄匹配的控件,性别,和种族是通过发病率密度抽样选择的。Cox比例风险计算BMI和CRC风险关联(风险比[HRs];95%置信区间[CIs]。条件逻辑回归计算白蛋白和CRC风险关联(比值比[ORs];95CIs)。
结果:体重不足,但不是超重或肥胖,与正常BMI相比,CRC风险增加(HR:1.75,95CI:1.00~3.09).白蛋白的每个标准差增加与CRC风险降低相关,特别是那些自我认定为非西班牙裔黑人的人(OR:0.56,95CI:0.34-0.91),或女性(OR:0.54,95CI:0.30-0.98),但没有证据表明这些变量之间存在交互作用(p交互作用>0.05)。此外,黑种人的白蛋白浓度低于白种人。中介分析表明,白蛋白与CRC之间的关系不是由BMI介导的。
结论:超重/肥胖与CRC风险的零关联表明BMI的效用有限,尤其是在黑人群体中。低白蛋白可能提示CRC风险。在黑人个体中,白蛋白可能比BMI更好地预测肥胖相关风险。
BACKGROUND: Obesity may increase colorectal cancer (CRC) risk through mechanisms of increased inflammation. Although BMI is the most used adiposity indicator, it may less accurately measure adiposity in Black populations. Herein, we investigate associations between BMI, low albumin as an inflammation biomarker, and CRC risk in a racially diverse cohort.
METHODS: Participant data arise from 71,141 participants of the Southern Community Cohort Study, including 724 incident CRC cases. Within the cohort, 69% are Black. Blood serum albumin concentrations, from samples taken at enrollment, were available for 235 cases and 567 controls. Controls matched by age, sex, and race were selected through incidence density sampling. Cox proportional hazards calculated BMI and CRC risk associations (hazard ratios [HRs]; 95% confidence intervals [CIs]. Conditional logistic regression calculated albumin and CRC risk associations (odds ratios [ORs]; 95%CIs).
RESULTS: Underweight, but not overweight or obese, compared to normal BMI was associated with increased CRC risk (HR:1.75, 95%CI:1.00-3.09). Each standard deviation increase of albumin was associated with decreased CRC risk, particularly for those who self-identified as non-Hispanic Black (OR: 0.56, 95%CI:0.34-0.91), or female (OR:0.54, 95%CI:0.30-0.98), but there was no evidence for interaction by these variables (p-interactions > 0.05). Moreover, albumin concentration was lower in Black than White participants. Mediation analysis suggested that the relation between albumin and CRC was not mediated by BMI.
CONCLUSIONS: Null associations of overweight/obesity with CRC risk demonstrates limited utility of BMI, especially among Black populations. Low albumin may indicate CRC risk. In Black individuals, albumin may better predict adiposity related risks than BMI.