Urinary Cadmium Threshold to Prevent Kidney Disease Development.

Soisungwan Satarug,Patricia Ruiz,Werawan Ruangyuttikarn,Muneko Nishijo

doi:10.3390/toxics6020026

Soisungwan Satarug, Patricia Ruiz + Show 2 more

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https://doi.org/10.3390/toxics6020026

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Abstract

The frequently observed association between kidney toxicity and long-term cadmium (Cd) exposure has long been dismissed and deemed not to be of clinical relevance. However, Cd exposure has now been associated with increased risk of developing chronic kidney disease (CKD). We investigated the link that may exist between kidney Cd toxicity markers and clinical kidney function measure such as estimated glomerular filtration rates (eGFR). We analyzed data from 193 men to 202 women, aged 16−87 years [mean age 48.8 years], who lived in a low- and high-Cd exposure areas in Thailand. The mean (range) urinary Cd level was 5.93 (0.05–57) μg/g creatinine. The mean (range) for estimated GFR was 86.9 (19.6−137.8) mL/min/1.73 m2. Kidney pathology reflected by urinary β2-microglobulin (β2-MG) levels ≥ 300 μg/g creatinine showed an association with 5.32-fold increase in prevalence odds of CKD (p = 0.001), while urinary Cd levels showed an association with a 2.98-fold greater odds of CKD prevalence (p = 0.037). In non-smoking women, Cd in the highest urinary Cd quartile was associated with 18.3 mL/min/1.73 m2 lower eGFR value, compared to the lowest quartile (p < 0.001). Evidence for Cd-induced kidney pathology could thus be linked to GFR reduction, and CKD development in Cd-exposed people. These findings may help prioritize efforts to reassess Cd exposure and its impact on population health, given the rising prevalence of CKD globally.

Highlights

Exposure to the heavy metal cadmium (Cd) is inevitable for most people as this metal is present in foodstuffs, cigarette smoke and polluted air [1,2,3,4]
We have demonstrated that a clinical kidney function measure such as estimated glomerular filtration rates could be linked to both Cd exposure and tubular toxicity in Cd-dose and toxicity severity dependent manner
We have shown that a urinary Cd level as low as

Summary

Introduction

Exposure to the heavy metal cadmium (Cd) is inevitable for most people as this metal is present in foodstuffs, cigarette smoke and polluted air [1,2,3,4]. The most frequently reported Cd toxicity in non-occupationally exposed populations is related to kidneys, notably the injury to the proximal tubular epithelial cells that reabsorb and concentrate Cd from the glomerular filtrate [1,2,3,4]. One of the consequential results of the injury and death of renal tubular epithelial cells by Cd is a reduction in tubular reabsorption capacity in Cd-exposed people, leading to loss of nutrients through urine, notably glucose, amino acids, calcium, and zinc [8,9,10,11]

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