Kidney Disease Research Collaborative, Translational Research Institute, Brisbane 4102, Australia.
Department of Nephrology, Princess Alexandra Hospital, Brisbane 4102, Australia.
Int J Environ Res Public Health. 2022 Nov 25;19(23):15697. doi: 10.3390/ijerph192315697.
Cadmium (Cd) is a toxic metal pollutant that accumulates, especially in the proximal tubular epithelial cells of kidneys, where it causes tubular cell injury, cell death and a reduction in glomerular filtration rate (GFR). Diet is the main Cd exposure source in non-occupationally exposed and non-smoking populations. The present study aimed to evaluate the reliability of a tolerable Cd intake of 0.83 μg/kg body weight/day, and its corresponding toxicity threshold level of 5.24 μg/g creatinine. The PROAST software was used to calculate the lower 95% confidence bound of the benchmark dose (BMDL) values of Cd excretion (E) associated with injury to kidney tubular cells, a defective tubular reabsorption of filtered proteins, and a reduction in the estimated GFR (eGFR). Data were from 289 males and 445 females, mean age of 48.1 years of which 42.8% were smokers, while 31.7% had hypertension, and 9% had chronic kidney disease (CKD). The BMDL value of E associated with kidney tubular cell injury was 0.67 ng/L of filtrate in both men and women. Therefore, an environmental Cd exposure producing E of 0.67 ng/L filtrate could be considered as Cd accumulation levels below which renal effects are likely to be negligible. A reduction in eGFR and CKD may follow when E rises from 0.67 to 1 ng/L of filtrate. These adverse health effects occur at the body burdens lower than those associated with E of 5.24 µg/g creatinine, thereby arguing that current health-guiding values do not provide a sufficient health protection.
镉 (Cd) 是一种有毒的金属污染物,尤其在肾脏近端肾小管上皮细胞中积累,导致肾小管细胞损伤、细胞死亡和肾小球滤过率 (GFR) 降低。饮食是职业暴露和不吸烟人群中镉暴露的主要来源。本研究旨在评估 0.83μg/kg 体重/天的可耐受镉摄入量的可靠性,以及其相应的毒性阈值 5.24μg/g 肌酐。使用 PROAST 软件计算与肾小管细胞损伤、滤过蛋白肾小管重吸收缺陷和估计肾小球滤过率 (eGFR) 降低相关的镉排泄 (E) 的基准剂量 (BMDL) 值的下限 95%置信区间。数据来自 289 名男性和 445 名女性,平均年龄为 48.1 岁,其中 42.8%为吸烟者,31.7%患有高血压,9%患有慢性肾脏病 (CKD)。男性和女性与肾小管细胞损伤相关的 E 的 BMDL 值均为 0.67ng/L 滤液。因此,环境镉暴露导致 E 为 0.67ng/L 滤液时,可能被认为是肾效应可能微不足道的镉积累水平。当 E 从 0.67ng/L 滤液上升到 1ng/L 滤液时,eGFR 降低和 CKD 可能会随之发生。这些不良健康影响发生在低于与 E 为 5.24μg/g 肌酐相关的身体负荷水平,这表明当前的健康指导值不能提供充分的健康保护。