Association between multiple metal(loid)s exposure and renal function: a cross-sectional study from southeastern China

Rural-urban difference in the association between particulate matters and stroke incidence: The evidence from a multi-city perspective cohort study

Available evidence suggests that air pollutants can cause stroke, but little research has investigated the confounding effects of urban-rural differences. Here, we investigated the urban-rural difference in the correlation between particulate matter (PM2.5 and PM10) exposure and stroke. This cohort study was based on a prospective multi-city community-based cohort (Guizhou Population Health Cohort Study (GPHCS)) in Guizhou Province, China. A total of 7988 eligible individuals (≥18 years) were enrolled with baseline assessments from November 2010 to December 2012, and follow-up was completed by June 2020. Two major particulate matters (PMs, including PM2.5 and PM10) were assessed monthly from 2000 by using satellite-based spatiotemporal models. The risk of stroke was estimated using a Cox proportional hazard regression model. The association between particulate matters' exposure and stroke in different areas (total, urban, and rural) and the potential modification effect of comorbidities (hypertension, diabetes, and dyslipidemia) and age (≤65/>65 years) were examined using stratified analyses. The risk of stroke increased for every 10 μg/m3 increase in mean PMs' concentrations during the previous 1 year at the residential address (HR: 1.26, 95%CI: 1.24, 1.29 (PM2.5); HR: 1.13, 95%CI: 1.11, 1.15 (PM10)). The presence of diabetes and dyslipidemia increased the risk of PM10-induced stroke in whole, urban, and rural areas. Specifically, people living in rural areas were more likely to experience the effects of PMs in causing a stroke. The risk of stroke due to PMs was statistically increased in the young and older populations living in rural areas. In conclusion, long-term exposure to PMs increased the risk of stroke and such association was more pronounced in people living in rural areas with lower income levels. Diabetes and dyslipidemia seemed to strengthen the association between PMs and stroke.

Association between blood heavy metals and diabetic kidney disease among type 2 diabetic patients: a cross-sectional study

Studies on the correlation of exposure to metals with diabetic kidney disease (DKD) is scarce, especially concerning the impact of mixed metals on DKD. This study aimed to explore the association of blood heavy metals with DKD risk among type 2 diabetes mellitus (T2DM) patients. This cross-sectional study enrolled patients with T2DM in NHANES 2011-2020. ICP‒MS was applied to detect five metals, namely, Pb, Cd, Hg, Se and Mn, in blood. At the same time, the impacts of exposure to single and mixed metals on DKD were assessed using multivariable logistic regression, WQS, and BKMR models. The relationship was examined based on age, sex, BMI, hypertension, smoking status and PIR. Totally 2362 participants were enrolled for final analysis. Among them, 634 (26.84%) patients undergoing T2DM had DKD. Logistic regression indicated that, Pb (Q4: OR [95% CI]: 1.557 [1.175, 2.064]) was related to DKD when all covariates were adjusted. The WQS analysis, which was set in a positive directional mode, suggested that Pb was correlated positively with a higher incidence of DKD. In BKMR analysis, linear dose‒response curves were generated for Pb when fixing the other metals in the 50th percentile. In addition, exposure to mixed metals was significantly positively related to DKD. Subgroup analysis during logistic regression demonstrated that Pb was significantly and positively related to DKD in females, over 50 years, those with over 25 kg/m2, no hypertension, no smoking status and under PIR. Serum albumin (ALB) did not regulate the indirect impact of blood Pb on DKD risk. The results showed that the increased mixed metal concentration may lead to an increased DKD risk among patients with T2DM. Blood Pb is positively related to the DKD risk in diabetic patients, especially, in females, over 50 years, those with over 25 kg/m2, no hypertension, no smoking status and under PIR in T2DM patients. According to our observations, Pb absorption at least slightly influences DKD occurrence and progression. More studies are needed to validate the results in this work and illustrate the relevant biological mechanism.

Associations between multi-metal joint exposure and decreased estimated glomerular filtration rate (eGFR) in solar greenhouse workers: A study of a unique farmer group

BACKGROUND

Solar greenhouse workers, a unique farmer group, have been reported to have a higher risk of chronic kidney disease (CKD) compared to the general population, possible due to exposure to multiple metals.

OBJECTIVE

This study aimed to investigate the associations between exposure to multiple metals and the estimated glomerular filtration rate (eGFR).

METHODS

A cross-sectional study was conducted in the Northwest China. Urine samples were tested for concentration of 14 metals, including chromium, manganese, iron et al. Blood creatinine was measured to calculate eGFR, which was to evaluate the kidney function. Linear model and the Bayesian Kernel Machine Regression (BKMR) models were used to evaluate the associations between metals exposure and eGFR.

RESULT

The study included 281 solar greenhouse workers, with 128 (45.6%) males and 153 (54.4%) females. The highest median concentrations of metals were zinc (418.55 μg/L), strontium (368.77 μg/L), and iron (55.73 μg/L), respectively. The linear model analysis showed that urinary levels of copper and zinc were negatively associated with eGFR [β = -0.021, 95% CI (-0.048, -0.007); β = -0.018, 95% CI (-0.068, -0.005)] considering a false discovery rate. BKMR results indicated a significant overall negative effect of 14 metals exposure on the eGFR when all metal levels were above the 50th percentile compared to the median value.

CONCLUSIONS

The decrease in eGFR among solar greenhouse workers was related to mixed metal exposure. Reducing exposure to the metals of copper, zinc, and lead could effectively protects kidney function. Further prospective studies are needed to resolve concerns about reverse causality.

Association Between Multiple Metal(loid)s Exposure and Blood Lipid Levels: Evidence from a Cross-Sectional Study of Southeastern China

Exposure to essential and toxic metals occurs simultaneously as a mixture in real-life. However, there is no consensus regarding the effects of co-exposure to multiple metal(loid)s (designated hereafter metals) on blood lipid levels. Thus, blood concentrations of six human essential metals and five toxic metals in 720 general populations from southeastern China were simultaneously determined as a measure of exposure. In addition, quantile g-computation, Bayesian kernel machine regression, elastic net regression, and generalized linear model were used to investigate both the joint and individual effects of exposure to this metal mixture on human blood lipid levels. The significant positive joint effect of exposure to this metal mixture on serum total cholesterol (TC) levels, rather than on serum triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, Castelli risk index I, Castelli risk index II, atherogenic coefficient, and non-HDL-C levels, was found. In addition, the positive effect may be primarily driven by selenium (Se), lead (Pb), and mercury (Hg) exposure. In addition, on the effect of TC levels, the synergistic effect between Pb and Hg and the antagonistic effect between Se and Pb were identified. Our finding suggests that combined exposure to this metal mixture may affect human blood lipid levels. Therefore, reducing exposure to heavy metals, such as Pb and Hg, should be a priority for the general population. In addition, Se supplementation should also be considered with caution.

Associations among environmental exposure to trace elements and biomarkers of early kidney damage in the pediatric population

BACKGROUND

In kidney damage, molecular changes can be used as early damage kidney biomarkers, such as Kidney Injury Molecule-1 and Neutrophil gelatinase-associated lipocalin. These biomarkers are associated with toxic metal exposure or disturbed homeostasis of trace elements, which might lead to serious health hazards. This study aimed to evaluate the relationship between exposure to trace elements and early damage kidney biomarkers in a pediatric population.

METHODS

In Tlaxcala, a cross-sectional study was conducted on 914 healthy individuals. The participants underwent a medical review and a socio-environmental questionnaire. Five early damage kidney biomarkers were determined in the urine with Luminex, and molybdenum, copper, selenium, nickel, and iodine were measured with ICP-Mass.

RESULTS

The eGFR showed a median of 103.75 mL/min/1.73 m2. The median levels for molybdenum, copper, selenium, nickel, and iodine were 24.73 ng/mL, 73.35 ng/mL, 4.78 ng/mL, 83.68 ng/mL, and 361.83 ng/mL, respectively. Except for molybdenum and nickel, the other trace elements had significant associations with the eGFR and the early kidney damage biomarkers. Additionally, we report the association of different exposure scenarios with renal parameters.

DISCUSSION

and Conclusions. Among the explored metals, exposure to Cu and iodine impairs renal function. In contrast, Se may manifest as a beneficial metal. Interactions of Mo-Se and Mo-Iodine seem to alter the expression of NGAL; Mo-Cu for CLU; Mo-Cu, Mo-Se, and Mo-iodine for Cys-C and a-1MG; and Mo-Cu and Mo-iodine for KIM-1; were noticed. Our study could suggest that trace element interactions were associated with early kidney damage biomarkers.

Exposure to cadmium and lead is associated with diabetic kidney disease in diabetic patients

BACKGROUND

Cadmium (Cd) and lead (Pb) exhibit nephrotoxic activity and may accelerate kidney disease complications in diabetic patients, but studies investigating the relation to diabetic kidney disease (DKD) have been limited. We aimed to examine the associations of Cd and Pb with DKD in diabetic patients.

METHODS

3763 adults with blood metal measurements and 1604 adults with urinary ones who were diabetic from National Health and Nutrition Examination Survey (NHANES) 2007-2016 were involved. Multivariate logistic regression models were used to analyze the associations of blood Cd (BCd), blood Pb (BPb), urinary Cd (UCd), and urinary Pb (UPb) with DKD.

RESULTS

BPb, BCd, and UCd levels were higher among participants with DKD than diabetics without nephropathy, but UPb performed the opposite result. BPb and UCd were significantly associated with DKD in the adjusted models (aOR, 1.17 (1.06, 1.29);1.52 (1.06, 2.02)). Participants in the 2nd and 3rd tertiles of BPb and BCd levels had higher odds of DKD, with a significant trend across tertiles, respectively (all P-trend < 0.005). Multiplication interaction was also identified for BPb and BCd (P for interaction = 0.044).

CONCLUSION

BPb, BCd, and UCd were positively associated with the risk of DKD among diabetic patients. Furthermore, there were the dose-response relationship and multiplication interaction in the associations of BPb, BCd with DKD.