National Council of Science and Technology, National Institute of Public Health, Mexico City, MX, Mexico.
Department of Health, Universidad Iberoamericana, Mexico City, MX, Mexico.
Environ Res. 2021 May;196:110980. doi: 10.1016/j.envres.2021.110980. Epub 2021 Mar 7.
Exposure to environmental toxicants may play a role in the pathogenesis of Non Alcoholic Fatty Liver Disease (NAFLD). Cumulative exposure to lead (Pb) has chronic and permanent effects on liver function. Pediatric populations are vulnerable to the toxic effects of Pb, even at low exposure levels. The purpose of the study was to estimate the association between cumulative Pb exposure during childhood and hepatic steatosis biomarkers in young Mexican adults.
A subsample of 93 participants from the ELEMENT cohort were included in this study. Childhood blood samples were collected annually from ages 1-4 years and were used to calculate the Cumulative Childhood Blood Lead Levels (CCBLL). Hepatic steatosis during adulthood was defined as an excessive accumulation of hepatic triglycerides (>5%) determined using Magnetic Resonance Imaging (MRI). Liver enzymes were also measured at this time, and elevated liver enzyme levels were defined as ALT (≥30 IU/L), AST (≥30 IU/L), and GGT (≥40 IU/L). Adjusted linear regression models were fit to examine the association between CCBLL (quartiles) and the hepatic steatosis in young adulthood.
In adulthood, the mean age was 21.4 years, 55% were male. The overall prevalence of hepatic steatosis by MRI was 19%. Elevate levels of the enzymes ALT, AST, and GGT were present in 25%, 15%, and 17% of the sample, respectively. We found a positive association between the highest quartile of CCBLL with the steatosis biomarkers of hepatic triglycerides (Q4 vs. Q1: β = 6.07, 95% CI: 1.91-10.21), elevated ALT (Q4 vs. Q1: β = 14.5, 95% CI: 1.39-27.61) and elevated AST (Q4 vs. Q1: β = 7.23, 95% CI: 0.64-13.82). No significant associations were found with GGT.
Chronic Pb exposure during early childhood is associated with a higher levels of hepatic steatosis biomarkers and hepatocellular injury in young adulthood. More actions should be taken to eliminate sources of Pb during the first years of life.
环境毒物暴露可能在非酒精性脂肪性肝病（NAFLD）的发病机制中起作用。铅（Pb）的累积暴露对肝功能有慢性和永久性影响。儿科人群易受 Pb 的毒性影响，即使在低暴露水平下也是如此。本研究的目的是评估儿童期累积 Pb 暴露与年轻墨西哥成年人肝脂肪变性生物标志物之间的关联。
本研究纳入了 ELEMENT 队列的 93 名参与者的亚样本。从 1 至 4 岁起每年采集儿童期血样，并用于计算累积儿童期血铅水平（CCBLL）。成年期肝脂肪变性定义为使用磁共振成像（MRI）确定的肝内甘油三酯过度积聚（>5%）。此时还测量了肝酶，肝酶水平升高定义为 ALT（≥30 IU/L）、AST（≥30 IU/L）和 GGT（≥40 IU/L）。拟合调整后的线性回归模型以检查 CCBLL（四分位数）与年轻成年人肝脂肪变性之间的关联。
成年时，平均年龄为 21.4 岁，55%为男性。MRI 检测到的肝脂肪变性总患病率为 19%。在样本中，分别有 25%、15%和 17%的人出现 ALT、AST 和 GGT 酶水平升高。我们发现 CCBLL 最高四分位数与肝内甘油三酯的脂肪变性生物标志物（Q4 与 Q1：β=6.07，95%CI：1.91-10.21）、升高的 ALT（Q4 与 Q1：β=14.5，95%CI：1.39-27.61）和升高的 AST（Q4 与 Q1：β=7.23，95%CI：0.64-13.82）呈正相关。与 GGT 无显著相关性。
儿童早期慢性 Pb 暴露与年轻成年人肝脂肪变性生物标志物水平升高和肝细胞损伤有关。应采取更多行动在生命的最初几年消除 Pb 的来源。
