Low serum zinc is associated with elevated risk of cadmium nephrotoxicity

Altered Levels of Serum Zinc and Cadmium in Patients with Chronic Vesiculobullous Hand and Feet Dermatitis

Micronutrients serve many important functions in our body and altered levels of heavy and trace metals are associated with cutaneous and systemic disorders. Vesicular palmoplantar eczema is an entity whose etiopathogenesis is a mystery. In this prospective case-noncase study blood levels of Zinc and Cadmium in 37 patients of chronic vesiculobullous hand dermatitis were estimated and compared with 40 noncases with similar age and gender distributions. Low serum Zinc levels were found in patients as compared to noncases. The mean difference of serum Zinc between the case and noncase groups was 27.26; the mean value of serum Zinc between the two groups was statistically significant (p < 0.0001). However, elevated Cadmium levels were detected in only 5 patients and in none of the noncases. The mean concentration of serum Cadmium was 2.32 ± 0.38 μg/dL, with a range of 1.90–2.80 μg/dL for the five cases in whom Cadmium was detected. Various toxic and trace metals can interact by influencing each other's absorption, retention, distribution, and bioavailability in the body. The clinical significance of this finding lies in the possible beneficial role of Zinc supplementation in the therapy of chronic vesiculobullous hand dermatitis.

Zinc Intake Is Associated with Lower Cadmium Burden in U.S. Adults

BACKGROUND

Cadmium is a toxic transition metal whose absorption and accumulation might depend on zinc intake.

OBJECTIVE

We sought to determine whether zinc intake and serum zinc would be inversely associated with cadmium exposure.

METHODS

This study used data from NHANES 2003-2012, from which there were 6678 and 6488 participants with urinary and blood cadmium data, respectively, and 1195 participants with serum zinc data. Mean blood and urinary cadmium were reported by quintiles of zinc intake and by the dose and duration of zinc supplement use. The associations between zinc intake from diet and supplements, serum zinc, and blood and urinary cadmium were determined using multiple regression. Analyses were adjusted for age, body mass index, race/ethnicity, gender, income-to-poverty ratio, education, smoking status, and mean intakes of energy, calcium, and iron.

RESULTS

Urinary cadmium concentrations were 0.04 μg/g creatinine lower among participants in the highest compared with lowest quintile of total zinc intake (P-trend = 0.0041). Zinc supplement dose and duration were inversely associated with blood cadmium (P = 0.0372) and serum zinc (P-trend = 0.0017), respectively. In adjusted regression models, a 10% increase in total zinc intake corresponded to a predicted decrease in blood cadmium of 0.42% (95% CI: -0.79%, -0.06%; P = 0.0260) and in urinary cadmium of 0.42% (95% CI: -0.81%, -0.04%; P = 0.0340). A 10% increase in serum zinc was associated with a predicted 1.99% (95% CI: -3.17%, -0.81%; P = 0.0012) decrease in blood cadmium and a predicted 4.09% (95% CI: 2.14%, 6.04%, P = 0.0001) increase in urinary cadmium.

CONCLUSIONS

Dietary and serum zinc in US adults are associated with cadmium exposure, presumably by influencing the absorption and accumulation of cadmium. Whether the degree of reduction in cadmium exposure from greater zinc intake and status is causal or relevant from a public health perspective needs further investigation.

Cadmium transporters in the kidney and cadmium-induced nephrotoxicity

Among the organs in which the environmental pollutant cadmium causes toxicity, the kidney has gained the most attention in recent years. Numerous studies have sought to unravel the exact pathways by which cadmium enters the renal epithelial cells and the mechanisms by which it causes toxicity in the kidney. The purpose of this review is to present the progress made on the mechanisms of cadmium transport in the kidney and the role of transporter proteins in cadmium-induced nephrotoxicity.