Environmental factors contribute significantly to the pathogenesis of chronic kidney disease. However, these factors, and particularly the toxic effects of heavy metals, have not been completely evaluated. Among which, chromium is a widespread industrial contaminant that has been linked to nephrotoxicity in animal and occupational population studies. Nevertheless, its role in population renal health and its potential interactions with other nephrotoxic metals, such as lead and cadmium, remain unknown.
A team led by Dr. Shu-li Wang from the National Institute of Environmental Health Sciences assessed the association between exposure to chromium, lead, and cadmium with renal function using estimated glomerular filtration rate (eGFR) in an analysis of 360 Taiwanese adults aged 19–84 years from the National Nutrition and Health Survey in Taiwan (2005–2008). An eGFR of less than 90 ml/min/1.73m2 is considered as clinically reduced kidney function and < 60 as kidney damage. Dr. Wang and team found that doubling of urinary chromium or lead decreased the eGFR by -5.99 mL/min/1.73 m2 with 95% confidence interval (CI) of (-9.70, -2.27), and -6.61 (-9.71, -3.51), respectively, after adjusting for age, sex, body mass index, hypertension, diabetes, cigarette smoking, sodium intake, education, urinary volume, and other metals. Besides, in the highest tertile of cadmium exposure, the eGFR decreased by -12.68 mL/min/1.73 m2 (95% CI: -20.44, -4.93) and -11.22 mL/min/1.73 m2 (-17.01, -5.44), as urinary chromium or lead levels doubled, respectively.
These findings demonstrate a significant and independent association between chromium exposure and decreased renal function. Furthermore, participants with cadmium, lead and chromium over the median appears to have accelerated kidney aging by around 10 years particularly for aged 30-60 year old group. The need is suggested for environmental modification and legislative changes to improve population renal health.
Ref: Tsai, TL; Kuo, CC; Pan, WH; Chung, YT; Chen, CY; Wu, TN; Wang, SL. The decline in kidney function with chromium exposure is exacerbated with co-exposure to lead and cadmium. Kidney International. 2017 Sep;92(3):710-720.