Relationship between exposure to cadmium, lead, and mercury and the occurrence of urinary incontinence in women

Cadmium, lead, and mercury are nephrotoxic metals that are commonly found as hazardous pollutants in many areas of the USA. We examined the relationship between exposure to cadmium, lead, and mercury with the occurrence of urgency urinary incontinence (UUI) and stress urinary incontinence (SUI) in women. This study was conducted using data on women > 20 years of age, collected between 2005 and 2016, who reported experiencing urinary incontinence in the National Health and Nutrition Examination Survey (NHANES). Restricted cubic spline analysis was used to characterize a dose-response relationship between continuous exposure to different nephrotoxic metals and the occurrence of UUI and SUI. A total of 4406 women were included in this study, with 2624 (59.6%) suffering from SUI and 3177 (72.1%) suffering from UUI in the weighted population. The results of our multivariate analysis indicated that age, race, marital status, body mass index (BMI), and exposure to nephrotoxic metals were risk factors for developing UI. The odds ratio (OR; 95% confidence interval) for developing UI was positively correlated with the exposure to cadmium and lead in women. The OR of SUI occurrence increased with increasing levels of cadmium in blood, with a peak at 4 µg/L. The OR of UUI occurrence increased with increasing levels of blood and urinary lead, with peaks at 7 µg/dL and 5 µg/L, respectively. The presence of mercury was not significantly correlated with the occurrence of SUI or UUI. Exposure to high levels of cadmium and lead, which are nephrotoxic metals, is associated with the occurrence of UI in women.

Nephrotoxic metals of cadmium, lead, mercury and arsenic and the odds of kidney stones in adults: An exposure-response analysis of NHANES 2007-2016

BACKGROUND

Nephrotoxic metals of arsenic, cadmium, lead and mercury exposures are common environmental pollutants. The associations between arsenic, cadmium, lead and mercury exposures and the risk of kidney stones are unclear.

OBJECTIVE

To explore the associations between biomarkers of arsenic, cadmium, lead and mercury exposures and the odds of kidney stones.

METHODS

Adult participants (≥20 years) from the 2007-2016 NHANES were included. Restricted cubic splines were adopted.

RESULTS

The odds ratio (95% confidence interval) of kidney stones increased with increasing blood cadmium and reached the maximum at 1.00 μg/L [1.38 (1.02-1.88) overall, 1.62 (1.11-2.32) for women and 1.53 (1.06-2.22) for non-Hispanic white]. The odds of kidney stones increased with increasing urinary cadmium and reached the maximum at 1.50 μg/L [2.56 (1.17-5.59) overall, 5.57 (1.88-16.49) for women, 4.31 (1.75-10.63) for obese individuals and 3.75 (1.60-8.78) for non-Hispanic white]. The odds of kidney stones increased with increasing total urinary arsenic and urinary dimethylarsinic acid in women, and reached the maximum of 1.69 (1.08-2.67) at 40 μg/L and 1.71 (1.07-2.72) at 10.00 μg/L, respectively. Inverse associations were found between the odds of kidney stones and blood lead within 5.00 μg/dL [0.64 (0.46-0.90) overall, 0.53 (0.33-0.84) for men and 0.58 (0.37-0.92) for non-Hispanic white], methyl mercury within 3.00 μg/L [non-obese individuals: 0.71 (0.51-0.99)] and urinary arsenous acid within 1.20 μg/L [individuals other than non-Hispanic white: 0.63 (0.41-0.95)]. No association was found with other biomarkers.

CONCLUSIONS

Several biomarkers of arsenic, cadmium, lead and mercury exposures were associated with the odds of kidney stones in adults.

Chronic kidney disease of unknown aetiology in Sri Lanka and the exposure to environmental chemicals: a review of literature

Chronic kidney disease of unknown aetiology (CKDu) has emerged as a serious health issue in Sri Lanka. The disease has been recorded in the North Central Province of the country. While studies have elicited many hypotheses concerning the pathogenicity of CKDu, none adequately explains the cause of CKDu and the measures needed to minimise its occurrence. Nephrotoxic heavy metal (oid)s such as cadmium, arsenic, lead, and chromium are present in biological samples of people from endemic areas. This review appraises evidence on the effects of long-term exposure to low concentration of nephrotoxic heavy metals, which could be the principal cause of CKDu. Although a considerable variation exists in metal concentrations in patients' blood and urine, higher levels of heavy metals were consistently observed in affected areas. This review finds that the populations in the endemic areas are exposed to heavy metal (oid)s at low concentrations, which are considered as safe levels; nevertheless, it influences the incidence of CKDu. Recent global studies on chronic kidney disease (CKD) revealed a low concentration of heavy metals in diseased patients. Research findings indicated that CKDu patients in Sri Lanka demonstrated similar blood levels of Cd, Pb, and higher concentrations of Cr than that have been reported globally. Further studies on the influence of combinations of nephrotoxic heavy metals at low concentrations on reduced glomerular filtration rate and other renal biomarkers could explain CKDu pathogenicity.