Epidemiology Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, 109 TW Alexander Drive, Research Triangle Park, NC 27711, USA.
Environ Health. 2010 Feb 26;9:11. doi: 10.1186/1476-069X-9-11.
Results from previous population studies showed that mortality rates from acute myocardial infarction and type-2 diabetes during the 1980s and 1990s in rural, agricultural counties of Minnesota, Montana, North and South Dakota, were higher in counties with a higher level of spring wheat farming than in counties with lower levels of this crop. Spring wheat, one of the major field crops in these four states, was treated for 85% or more of its acreage with chlorophenoxy herbicides. In the current study NHANES III data were reviewed for associations of 2,4-dichlorophenoxy acetic acid (2,4-D) exposure, one of the most frequently used chlorophenoxy herbicides, with risk factors that are linked to the pathogenesis of acute myocardial infarction and type-2 diabetes, such as dyslipidemia and impaired glucose metabolism.
To investigate the toxicity pattern of chlorophenoxy herbicides, effects of a previous 2,4-D exposure were assessed by comparing levels of lipids, glucose metabolism, and thyroid stimulating hormone in healthy adult NHANES III subjects with urinary 2,4-D above and below the level of detection, using linear regression analysis. The analyses were conducted for all available subjects and for two susceptible subpopulations characterized by high glycosylated hemoglobin (upper 50th percentile) and low thyroxine (lower 50th percentile).
Presence of urinary 2,4-D was associated with a decrease of HDL levels: 8.6% in the unadjusted data (p-value = 0.006), 4.8% in the adjusted data (p-value = 0.08), and 9% in the adjusted data for the susceptible subpopulation with low thyroxine (p-value = 0.02). An effect modification of the inverse triglycerides-HDL relation was observed in association with 2,4-D. Among subjects with low HDL, urinary 2,4-D was associated with increased levels of triglycerides, insulin, C-peptide, and thyroid stimulating hormone, especially in the susceptible subpopulations. In contrast, subjects with high HDL did not experience adverse 2,4-D associated effects.
The results indicate that exposure to 2,4-D was associated with changes in biomarkers that, based on the published literature, have been linked to risk factors for acute myocardial infarction and type-2 diabetes.
先前的人群研究结果表明，20 世纪 80 年代和 90 年代明尼苏达州、蒙大拿州、北达科他州和南达科他州农村农业县的急性心肌梗死和 2 型糖尿病死亡率，在春小麦种植水平较高的县高于种植水平较低的县。春小麦是这四个州的主要大田作物之一，其 85%以上的种植面积都使用了氯苯氧酸类除草剂进行处理。在当前的研究中，对 NHANES III 数据进行了回顾，以研究 2,4-二氯苯氧乙酸（2,4-D）暴露与急性心肌梗死和 2 型糖尿病发病机制相关的风险因素之间的关联，如血脂异常和葡萄糖代谢受损。
为了研究氯苯氧酸类除草剂的毒性模式，通过比较健康的 NHANES III 受试者尿液中 2,4-D 检测值以上和以下的脂质、葡萄糖代谢和促甲状腺激素水平，评估了先前 2,4-D 暴露的影响，使用线性回归分析。对所有可获得的受试者以及两个具有高糖化血红蛋白（上 50 百分位）和低甲状腺素（下 50 百分位）特征的易感亚群进行了分析。
尿液中存在 2,4-D 与 HDL 水平降低有关：未经调整的数据中为 8.6%（p 值=0.006），调整后的数据中为 4.8%（p 值=0.08），调整后具有低甲状腺素的易感亚群中的数据为 9%（p 值=0.02）。观察到 2,4-D 与逆甘油三酯-HDL 关系的效应修饰。在 HDL 水平较低的受试者中，尿液中的 2,4-D 与甘油三酯、胰岛素、C 肽和促甲状腺激素水平升高有关，尤其是在易感亚群中。相比之下，HDL 水平较高的受试者没有经历与 2,4-D 相关的不良反应。
研究结果表明，接触 2,4-D 与生物标志物的变化有关，根据已发表的文献，这些变化与急性心肌梗死和 2 型糖尿病的风险因素有关。
