Background

Previously we showed that adulthood body mass index (BMI) trajectories that result in obesity were associated with elevated risks of fatal prostate cancer (PCA). To further explore this relationship, we conducted a study within the NIH-AARP Diet and Health Study.

Methods

Among 153 730 eligible men enrolled in the NIH-AARP cohort from 1995 to 1996 (median follow-up = 15.1 years), we identified 630 fatal PCA cases and 16 896 incident cases. BMI was assessed for ages 18, 35 and 50 and at study entry, enabling examination of latent class-identified BMI trajectories. Hazard ratios (HRs) and 95% confidence intervals (CI) were estimated using Cox proportional hazards regression.

Results

BMI at study entry (mean age = 63, HR = 1.12; 95% CI = 1.01, 1.24, per 5-unit increase) and maximum BMI during adulthood (HR = 1.12; 95% CI = 1.02, 1.24, per 5-unit increase) shared modest associations with increased risk of fatal PCA. Smoking status likely modified the relationship between BMI trajectories and fatal PCA (Pinteraction = 0.035 via change-in-estimate variable section, P=0.065 via full a priori model). Among never-smokers, BMI trajectory of normal weight to obesity was associated with increased risk of fatal disease (HR = 2.37; 95% CI = 1.38, 4.09), compared with the maintained normal weight trajectory, whereas there was no association among former or current-smokers. Total and non-aggressive PCA exhibited modest inverse associations with BMI at all ages, whereas no association was observed for aggressive PCA.

Conclusions

Increased BMI was positively associated with fatal PCA, especially among never-smokers. Future studies that examine PCA survival will provide additional insight as to whether these associations are the result of biology or confounding.

中文翻译：

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成年期体重指数轨迹和吸烟与前列腺癌风险的关系：NIH-AARP 饮食与健康研究

背景

此前我们表明，导致肥胖的成年期体重指数 (BMI) 轨迹与致命性前列腺癌 (PCA) 风险升高相关。为了进一步探讨这种关系，我们在 NIH-AARP 饮食与健康研究中进行了一项研究。

方法

从 1995 年到 1996 年，在 NIH-AARP 队列中登记的 153 730 名符合条件的男性中（中位随访 = 15.1 年），我们发现了 630 例致命 PCA 病例和 16 896 例事故病例。在研究进入时对 18、35 和 50 岁的 BMI 进行评估，从而能够检查潜在的类别识别 BMI 轨迹。使用 Cox 比例风险回归估计风险比 (HR) 和 95% 置信区间 (CI)。

结果

研究开始时的 BMI（平均年龄 = 63，HR = 1.12；95% CI = 1.01, 1.24，每增加 5 单位）和成年期最大 BMI（HR = 1.12；95% CI = 1.02, 1.24，每 5 单位增加）与致命 PCA 风险增加有一定的关联。吸烟状况可能改变了 BMI 轨迹和致命性 PCA 之间的关系（通过估计变量部分的变化，Pinteraction = 0.035，通过完整先验模型 P=0.065）。在从不吸烟者中，与保持正常体重轨迹相比，正常体重到肥胖的 BMI 轨迹与致命疾病风险增加相关（HR = 2.37；95% CI = 1.38，4.09），而以前或肥胖之间没有关联。当前吸烟者。总 PCA 和非攻击性 PCA 在所有年龄段都与 BMI 呈适度负相关，而攻击性 PCA 则没有观察到相关性。

结论

BMI 增加与致命性 PCA 呈正相关，尤其是在从不吸烟的人群中。未来检查 PCA 存活率的研究将提供更多关于这些关联是生物学还是混杂因素的结果的见解。