Department of Epidemiology, University of Iowa College of Public Health, Iowa City, IA, USA.
Department of Epidemiology, University of Iowa College of Public Health, Iowa City, IA, USA.
Cancer Epidemiol. 2023 Aug;85:102410. doi: 10.1016/j.canep.2023.102410. Epub 2023 Jul 4.
In the United States (US), the average annual increase in the incidence of prostate cancer (PCa) has been 0.5% between 2013 and 2017. Although some modifiable factors have been identified as the risk factors for PCa, the effect of lower ratio of omega-6 to omega-3 fatty acids intake (N-6/N-3) remains unknown. Previous studies of the Agricultural Health Study (AHS) reported a significant positive association between PCa and selected organophosphate pesticides (OPs) including terbufos and fonofos.
The aim of this study was to evaluate the association between N-6/N-3 and PCa and any interaction between N-6/N-3 and 2 selected OPs (i.e., terbufos and fonofos) exposure.
This case-control study, nested within a prospective cohort study, was conducted on a subgroup of the AHS population (1193 PCa cases and 14,872 controls) who returned their dietary questionnaire between 1999 and 2003 MAIN OUTCOME MEASURES: PCa was coded based on the International Classification of Diseases of Oncology (ICD-O-3) definitions and obtained from the statewide cancer registries of Iowa (2003-2017) and North Carolina (2003-2014).
Multivariate logistic regression analysis was applied to obtain the odds ratios adjusted (aORs) for age at dietary assessment (years), race/ethnicity (white, African American, other), physical activity (hours/week), smoking (yes/no), terbufos (yes/no), fonofos (yes/no), diabetes, lycopene intake (milligrams/day), family history of PCa, and the interaction of N-6/N-3 with age, terbufos and fonofos. Pesticide exposure was assessed by self-administrated questionnaires collecting data on ever/never use of mentioned pesticides during lifetime as a yes/no variable. Assessing the P value for the interaction between pesticides and N-6/N-3, we used the continuous variable of "intensity adjusted cumulative exposure" to terbufos and fonofos. This exposure score was based on duration, intensity and frequency of exposure. We also conducted a stratified regression analysis by quartiles of age.
Relative to the highest N-6/N-3 quartile, the lowest quartile was significantly associated with a decreased risk of PCa (aOR=0.61, 95% CI: 0.41-0.90), and quartile-specific aORs decreased toward the lowest quartile (P=<0.01). Based on the age-stratified analysis, the protective effect was only significant for the lowest quartile of N-6/N-3 among those aged between 48 and 55 years old (aORs=0.97, 95% CI, 0.45-0.55). Among those who were exposed to terbufos (ever exposure reported as yes in the self-report questionnaires), lower quartiles of N-6/N-3 were protective albeit nonsignificant (aORs: 0.86, 0.92, 0.91 in quartiles 1,2, and 3, respectively). No meaningful findings were observed for fonofos and N-6/N-3 interaction.
Findings showed that lower N-6/N-3 may decrease risk of PCa among farmers. However, no significant interaction was found between selected organophosphate pesticides and N-6/N-3.
在美国，2013 年至 2017 年间前列腺癌（PCa）的发病率平均每年增长 0.5%。尽管已经确定了一些可改变的因素是 PCa 的风险因素，但ω-6 与 ω-3 脂肪酸摄入比例（N-6/N-3）的影响仍不清楚。之前农业健康研究（AHS）的研究报告称，PCa 与包括特丁磷和丰索磷在内的某些有机磷农药（OPs）之间存在显著正相关。
本研究旨在评估 N-6/N-3 与 PCa 的关系，以及 N-6/N-3 与 2 种选定的 OPs（即特丁磷和丰索磷）暴露之间的任何相互作用。
这是一项病例对照研究，嵌套在一项前瞻性队列研究中，在 AHS 人群的一个亚组（1193 例 PCa 病例和 14872 例对照）中进行，这些人在 1999 年至 2003 年期间返回了他们的饮食问卷。
PCa 根据国际肿瘤疾病分类（ICD-O-3）的定义，并从爱荷华州（2003-2017 年）和北卡罗来纳州（2003-2014 年）的全州癌症登记处获得。
应用多变量逻辑回归分析，获得调整后的比值比（aORs），用于年龄（年）、种族/族裔（白人、非裔美国人、其他）、体力活动（小时/周）、吸烟（是/否）、特丁磷（是/否）、丰索磷（是/否）、糖尿病、番茄红素摄入量（毫克/天）、前列腺癌家族史，以及 N-6/N-3 与年龄、特丁磷和丰索磷的相互作用。通过自我管理的问卷评估农药暴露，收集一生中是否使用过提到的农药的终生数据，作为一个是/否的变量。为了评估农药和 N-6/N-3 之间的相互作用的 P 值，我们使用了特丁磷和丰索磷的“强度调整累积暴露”的连续变量。该暴露评分基于暴露的持续时间、强度和频率。我们还按年龄四分位数进行了分层回归分析。
与最高 N-6/N-3 四分位相比，最低四分位与 PCa 风险降低显著相关（aOR=0.61，95%CI：0.41-0.90），四分位特异性 aOR 随最低四分位而降低（P<0.01）。基于年龄分层分析，在 48 至 55 岁之间的最低 N-6/N-3 四分位中，保护作用仅显著（aORs=0.97，95%CI，0.45-0.55）。在接触特丁磷的人群中（自我报告问卷中报告有接触），较低的 N-6/N-3 四分位有保护作用，但无统计学意义（aORs：1、2、3 分位分别为 0.86、0.92、0.91）。丰索磷和 N-6/N-3 之间没有发现有意义的相互作用。
研究结果表明，较低的 N-6/N-3 可能会降低农民患 PCa 的风险。然而，在选定的有机磷农药和 N-6/N-3 之间未发现显著的相互作用。
