Blood Cadmium Levels Research Articles

Assessing Cross-Sectional Association of Uremic Pruritus with Serum Heavy Metal Levels: A Single-Center Study

(1) Background: Uremic pruritus (UP) is a common and taxing symptom in patients on maintenance hemodialysis (MHD). We have previously shown that blood lead levels (BLLs) and blood aluminum levels (BALs) were separately positively associated with UP in MHD patients. We also found that blood cadmium levels (BCLs) were positively associated with all-cause mortality and cardiovascular-related mortality in MHD patients. We wondered whether there is any correlation between BCLs and UP after adjusting for BLLs and BALs. (2) Methods: Patients enrolled in this study were all from three hemodialysis (HD) centers at Chang Gung Memorial Hospital, Lin-Kou Medical Center, including both the Taipei and Taoyuan branches. Correlations between UP and BLLs, BALs, BCLs, and other clinical data were analyzed. (3) Results: Eight hundred and fifty-three patients were recruited. Univariate logistic regressions showed that diabetes mellitus, hepatitis B virus infection, hepatitis C virus infection, HD duration, hemodiafiltration, dialysis clearance of urea, normalized protein catabolic rate, non-anuria, serum albumin levels, log (intact-parathyroid hormone levels), total serum cholesterol levels, serum low-density lipoprotein levels, log (blood aluminum levels), and log (blood lead levels) were associated with UP. Although log BCLs were not significantly associated with UP (p = 0.136) in univariate analysis, we still included log BCLs in multivariate logistic regression to verify their effect on UP given that our aim in this study was to verify associations between serum heavy metals and UP. Multivariate logistic regressions showed that log BLLs (OR: 27.556, 95% CI: 10.912–69.587, p < 0.001) and log BALs (OR: 5.485, 95% CI: 2.985–10.079, p < 0.001) were positively associated with UP. The other logistic regression, which stratified BLLs and BALs into high and low BLLs and BALs, respectively, showed that high BLLs or high BALs (low BLLs and low BALs as reference) (OR: 3.760, 95% CI: 2.554–5.535, p < 0.001) and high BLLs and high BALs combined (low BLLs and low BALs as reference) (OR: 10.838, 95% CI: 5.381–21.828, p < 0.001) were positively correlated with UP. (4) Conclusions: BLLs and BALs were positively correlated with UP. BCLs were not correlated with UP. Clinicians should pay more attention to the environmental sources of lead and aluminum to prevent UP.

Leukocyte telomere length mediates the association between cadmium exposure and cognitive function in US older adults

BackgroundLong-term exposure to cadmium-polluted environments may lead to shortened leukocyte telomere length and cognitive decline. This study aims to investigate (1) the associations among blood cadmium levels, leukocyte telomere length, and cognitive function, and (2) the mediating role of leukocyte telomere length between blood cadmium levels and cognitive function among older adults in the United States. MethodsUsing data from the National Health and Nutrition Examination Survey (NHANES) 1999–2002. Cadmium exposure level was assessed by measuring cadmium levels in blood samples. Leukocyte telomere length was measured by quantitative polymerase chain reaction, and cognitive function was measured by the digit symbol substitution test (DSST). ResultsA total of 2185 older adults aged over 60 were included in this study, comprising 1109 (49.65%) males. Elevated blood cadmium levels were significantly associated with the risk of a decline in cognitive function (β = - 2.842, p = 0.018). Shorter leukocyte telomere lengths were significantly associated with a higher risk of a decline in cognitive function (β = 4.144, p = 0.020). The total indirect effect on the blood cadmium level and cognitive function via leukocyte telomere length was - 0.218 (p = 0.012). The mediation effect was estimated to be 0.218/2.084 × 100% = 10.46%. ConclusionThe findings suggest that cadmium exposure may increase the risk of cognitive impairment by causing shortened leukocyte telomere length.

Heavy metal levels and flavonoid intakes are associated with chronic obstructive pulmonary disease: an NHANES analysis (2007–2010 to 2017–2018)

BackgroundThe association between exposure to environmental metals and chronic obstructive pulmonary disease (COPD) is preventing chronic lung diseases. However, little is currently known about the interaction between heavy metals and flavonoids in relation to the risk of COPD. This study aims to bridge this knowledge gap by leveraging The National Health and Nutrition Examination Survey (NHANES) database to evaluate thecorrelation between blood levels of heavy metals (cadmium, lead, mercury) and the intake of various flavonoid compounds (isoflavones, anthocyanidins, flavan-3-ols, flavanones, flavones, flavonols, total flavonoids). Additionally, appropriate dietary recommendations are provided based on the study findings.Materials and methodsCross-sectional analysis was conducted using the 2007–2010 and 2017–2018 NHANES data. Specialized weighted complex survey design analysis software was used for data analysis. Multivariate logistic regression models and restricted cubic splines (RCS) were used to evaluate the relationship between blood heavy metal levels, flavonoids intake, and COPD incidence in all participants, and to explore the effect of different levels of flavonoids intake on COPD caused by heavy metal exposure.ResultsA total of 7,265 adults aged ≥ 40 years were analyzed. Higher levels of blood cadmium (Cd), blood lead and Anthocyanidin (AC) intake were independently associated with an increased risk of COPD (Cd highest quantile vs. lowest: OR = 1.73, 95% CI, 1.25–2.3; Lead highest quantile vs. lowest quantile: OR = 1.44, 95% CI, 1.11–1.86; AC highest quantile vs. lowest: OR = 0.73, 95% CI, 0.54–0.99). When AC intake exceeded 11.56 mg/d, the effect of Cd exposure on COPD incidence decreased by 27%, and this finding was more significant in smokers.ConclusionHigher levels of Cd (≥ 0.45ug/L) and lead (≥ 0.172 ug/L) were positively correlated with the risk of COPD among participants aged 40 years and above, while AC intake (≥ 11.56 mg/d) could reduce the risk related to blood Cd.

Whole blood cadmium levels and depressive symptoms in Chinese young adults: A prospective cohort study combing metabolomics

ObjectivesTo investigate the association between Cd exposure and depressive symptoms in Chinese young adults. And to investigate the potential metabolic changes associated with high blood Cd concentrations. MethodsWe conducted a cohort study in 2019 and 2021. Blood Cd and depressive symptoms were collected during baseline and follow-up. The nine-item Patient Health Questionnaire (PHQ-9) scores were used to assess depressive symptoms. We used the generalized linear mixed model to estimate the association between blood Cd levels and depressive symptoms. A metabolomic and lipidomic analysis based on liquid chromatography-mass spectrometry was conducted on a total of 679 blood samples. The metabolomic data were analyzed using variance analysis and linear mixed effects models. ResultsBlood Cd concentrations were significantly associated with increased severity of depression symptoms [odds ratio (OR) 2.07, 95% confidence interval (CI) 1.04–4.11]. Metabolomics analysis found 93 metabolites with significant statistical differences between the lowest blood Cd level group and the highest Cd level group. Among the 93 differential metabolites, 17 were enriched in 7 differential metabolic pathways. ConclusionsBlood Cd was associated with increased severity of depression symptoms in Chinese young adults. Cd exposure may affect depressive symptoms by inducing oxidative stress, inflammation, and disrupting amino acid metabolism.

Abstract 12996: Association Between Blood Cadmium Level and Congestive Heart Failure: Analysis of the NHANES 2017 - 2020

Introduction: Cadmium toxicity affects various organs, including the heart and kidneys. Whether the relationship between a broad range of cadmium levels, from normal to highly toxic and congestive heart failure (CHF), remains unclear. Hypothesis: Blood cadmium (Cd) level is associated with a higher prevalence of CHF. Methods: A nationwide cross-sectional study involving participants (≥ 18 years old) in the 2017 - 2020 NHANES was examined by using multiple logistic regression to determine the association between Cd levels and history of CHF informed by a doctor or other health professional. Results: Of 12,102 participants with blood cadmium (Cd) results were identified, of which mean age was 37±24 years, and 50.6% were female. The majority were White (33%), followed by Black (25%), Mexican American (13%), and Asian (10%). Among 8,074 participants with Cd results, 304 participants (3.8%) had a history of CHF. The participants were stratified into quartiles (Q) based on their Cd levels, with mean Cd levels of 0.08, 0.16, 0.29, and 0.93 μg/L for each quartile, respectively. Individuals in Q2, Q3, and Q4 were 2.48, 3.20, and 4.29 times more likely to experience CHF than those in Q1. (Q2: 95% CI 1.22, 5.06; Q3: 95% CI 1.61, 6.37; Q4: 95% CI 2.18, 8.45).After adjusting for age, gender, race, BMI, smoking status, high systolic blood pressure (<130 vs. >130 mmHg), diabetic status, and urine albumin creatinine ratio, participants in Q3 and Q4 remained at a higher risk of CHF compared to an individual in Q1, with a risk increase of 2.18 and 3.04, respectively. (Q3: 95% CI 1.02, 4.68; Q4: 95% CI 1.41, 6.52; Figure 1). While CHF was 2.11 times as likely to occur among participants in Q2 but not statically significant (Q2: 95% CI 0.97, 4.59; Figure 1). Conclusions: A graded association exists between blood cadmium levels, even within the non-toxic range, and an increased prevalence of CHF. Further longitudinal cohort studies are required to elucidate this relationship.

Lead, cadmium, and mercury blood levels in schoolchildren in southern Sweden: Time trends over the last decades

To prevent diseases arising from exposure to toxic metals, more knowledge about their temporal changes is needed, especially in children, the most vulnerable group.This study follows temporal changes in blood lead (BPb), mercury (BHg) and cadmium (BCd) levels in schoolchildren (8–11 years old) from two cities in southern Sweden. One blood sample per 773 children was used for time trend analyses between 2007 and 2022. One further blood sample re-sampled after 2 years, were used to assess intra-individual time trends of BPb (n = 377), BCd (n = 102) and BHg (n = 53) between 1979 and 2019.Geometric mean (range) of BPb, BCd and BHg concentrations during 2007–2022 was 9.9 (2.3–59), 0.09 (0.03–0.34) and 0.73 (0.02–8.2) μg/L, respectively. Living close to a Pb smelter resulted in higher levels of all three metals compared with living in the city or rural area. Annually, the concentrations clearly decreased for BPb (−4.9%, p < 0.001) and weakly for BCd (−0.6%, p = 0.013), while BHg slightly increased (+1.4%, p = 0.029). When stratified by residential area, the decrease of BCd and increase of BHg were significant only in the urban area (−1.8% and +2.8%, respectively; p < 0.01). The BPb decrease rate was the highest in the urban area followed by the rural and Pb smelter areas (−5.8% > -4.5% > -3.9%; p < 0.001). For children re-analysed during 1979–2019, a significant decrease was observed only for BPb (−6.8%; p < 0.001), with a 2% higher decrease rate in the period before than after the Pb-gasoline ban in 1994.The preventive measures against Pb pollution are reflected in the constant decrease of BPb levels over time. However, the area close to a Pb smelter, as indicated by a slower Pb decrease rate, might need further and stricter preventive measures. Exposure to Hg and Cd was low, however, the slight increase in BHg and only a minor decrease in BCd, indicate the need for continuous biomonitoring of children.

Lead and Cadmium (Pb, Cd) Levels Determination in the Blood of the Gasoline Station Workers

The inhalation of hazardous fumes from lead containing gasoline in the workplace has become a major public health concern. These gases include extremely dangerous poisons that can induce aberrant changes in the functioning of a variety of essential organs. The current study aimed to estimate the concentration of blood lead level (BLLs) and blood cadmium level in male working gasoline station and compared with healthy people. An atomic absorption spectrophotometer (AAS) was used to measure cadmium and lead levels in the blood. The findings of this investigation revealed that there was significant increase in age (P-value = 0.002), mean age of worker station (32.0 ± 11.99) while in the control group (22.85 ± 2.18), the result of blood lead level shown (1.92 ±1.54) in gasoline station while in the control group (1.63 ±0.04) no significant differences was observed (P-value = 0.238). The main of blood cadmium level was 0.005 ±0.0069 in the gasoline station while in the control group (0.069 ±0.011) no significant differences were observed (P- value = 0.5), the smokers (n = 13) has (P &gt; 0.426) mean BLL (21.60 ± 12.88 μg/dL), while non-smoking workers (n = 8) the BLL mean was 15.52 ± 6.80 μg/dL. The results also show that there is a correlation between age and blood lead level while no correlation was observed in blood cadmium level.

Heavy metal levels in the dairy production chain in China

AbstractThe aims of this study were to investigate the heavy metal pollution status and distribution and to analyze the relationships among metal concentrations of different links in the dairy production chain. Chromium (Cr), arsenic (As), cadmium (Cd), lead (Pb), copper (Cu), and zinc (Zn) levels in water, fodder, milk, blood, hair, and feces samples collected from cows from five dairy farms in China were measured. The concentrations of Cr, As, Cd, Pb, Cu, and Zn were 4.61–11.11, 0.06–0.46, 0.17–0.29, 2.84–4.23, 4.11–7.72, and 7.23–19.91 mg/kg in silage; 12.72–40.85, 0.76–2.40, 0.05–0.16, 4.73–9.16, 44.14–78.46, and 4148.51–4845.20 μg/L in milk; 33.59–60.73, 0.09–3.57, 0.29–1.78, 20.14–39.20, 821.34–1007.45, and 2665.10–4929.95 μg/L in blood; 0.59–1.06, 0.02–0.09, 0.08–0.11, 1.70–2.09, 6.45–8.64, and 9.73–1.56 mg/kg in hair; 31.75–296.35, 0.33–5.96, 0.18–0.53, 3.35–9.06, 12.27–41.39, and 56.54–196.34 mg/kg in feces, respectively. The concentrations of heavy metals in hair were higher than those in the other samples and when combined with the results from the silage and tissue samples, we can assume that cow's hair can be used as a biological indicator for heavy metal contamination in the dairy production chain.

Hair and Blood Levels of Aluminum, Cadmium, and Lead in Children with Autism from Egypt: Can Toxic Heavy Metals Increase the Risk of Autism?

Hair and Blood Levels of Aluminum, Cadmium, and Lead in Children with Autism from Egypt: Can Toxic Heavy Metals Increase the Risk of Autism?

Some metals and metalloids in the blood of three species of shorebirds increase while foraging during two-week migratory stopover in Delaware Bay, New Jersey

Most migratory shorebird species are declining, some are endangered, and some may be vulnerable to contaminants on long distance travel between wintering grounds and high latitude breeding grounds. We examined whether shorebirds accumulated trace elements at the Delaware Bay (New Jersey) stopover by testing the null hypothesis that there was no difference in the levels of arsenic, cadmium, chromium, lead, mercury, and selenium in blood of three species of shorebirds collected early in their stopover compared to levels in blood collected about two weeks later near the end of the stopover, before departing for breeding grounds. There were significantly higher levels of all metals and metalloids in the blood of ruddy turnstone (Arenaria interpres) later in May than earlier. There were seasonal increases in blood levels of arsenic and selenium for all three species. Chromium and lead levels also increased in red knots (Calidris canutus). These increases occurred although the birds were only present for about two weeks. Levels of arsenic, mercury, and lead in knots and selenium in sanderlings (Calidrris alba), exceeded reported effects levels. These results have potential implications for studying the refueling physiology, energetics, and feeding behavior of migratory shorebirds. However, they also suggest cause for concern because the increased contaminant loads occur in a short period, and the high metal level bolus received all in a few days may result in adverse effects.

Burden of diabetes attributable to dietary cadmium exposure in adolescents and adults in China

At present, the health risk assessment of cadmium exposure has become a major focus of environmental health research. However, there is still a lack of systematic research on the burden of diabetes (DM) attributable to dietary cadmium exposure in adolescents and adults in China. Using the top-down method, the blood cadmium level (B-Cd) of Chinese adolescents and adults from 2001 to 2023 was combined with the relative risk (RR) of cadmium-induced diabetes to calculate the population attribution score (PAF). Subsequently, PAF was used to assess the disease burden (DB) of diabetes caused by cadmium exposure, expressed in disability adjusted life years (DALYs), and attribution analysis was carried out for cadmium exposure from different sources. The average blood cadmium concentration in Chinese adolescents and adults was 1.54 ± 1.13 µg/L, and the burden of DM attributable to cadmium exposure was 56.52 (44.81, 70.33) × 105 DALYs. The contribution rate of dietary cadmium exposure was 59.78%, and the burden of DM attributable to dietary cadmium exposure was 337.86 (267.85, 420.42) × 108 DALYs. In addition, the highest blood cadmium concentrations were found in Henan, Shanxi, and Jiangxi provinces, while the highest burden of DM attributable to cadmium exposure was found in Jiangsu, Henan, and Guangdong provinces. Cadmium exposure is a risk factor for DM, and we need to take comprehensive action to reduce the burden of DM attributable to dietary cadmium from health, economic, and social perspectives.

Cadmium exposure is associated with decreased muscle strength in middle-aged and older adults.

Cadmium, a toxic heavy metal, is ubiquitous in the environment. No previous research has evaluated the relationship of blood and urine cadmium levels with muscle strength measured by isokinetic knee extensor strength. This analysis included participants who were aged 50 years or older and had measurements of cadmium in blood (n = 2052) and urine (n = 811) from the National Health and Nutrition Examination Survey. Blood and urine cadmium levels were assessed by atomic absorption spectrometry and inductively coupled plasma-mass spectrometry, respectively. Isokinetic dynamometry was used to assess knee extensor strength (peak force). Linear regression models were used to examine the association between cadmium exposure and peak force, with adjustment for potential confounders. The median values (25-75th percentiles) of blood cadmium and creatinine-corrected urine cadmium were 0.50 μg/L (0.40-0.70) and 0.43 μg/g (0.27-0.71), respectively. After adjusting for potential confounders, linear dose-response relationships of peak force with blood and urine cadmium concentrations were observed in the present study. Compared to participants in the highest quartile of blood cadmium and urine cadmium, the peak force decreased by 6.99 Newton (95% CI: -21.96, 7.98) and 26.84 Newton (95% CI: -44.34, -9.34) in participants in the lowest quartiles, respectively. The observed associations were more evident among men participants. Our findings suggest that the cadmium levels have a dose response relationship with decreased muscle strength measured by isokinetic knee extensor strength in middle aged and older adults. Further longitudinal investigations are required to disentangle these complexities on this issue.

Blood and Urinary Metal Levels among Exclusive Marijuana Users in NHANES (2005-2018).

Marijuana is the third most used drug in the world. Because the cannabis plant is a known scavenger of metals, we hypothesized that individuals who use marijuana will have higher metal biomarker levels compared with those who do not use. We combined data from the National Health and Nutrition Examination Survey (2005-2018) for participants, classified by use: non-marijuana/non-tobacco, exclusive marijuana, exclusive tobacco, and dual marijuana and tobacco use. Five metals were measured in blood and 16 in urine using inductively coupled plasma mass spectrometry; urinary metals were adjusted for urinary creatinine. Participants reporting exclusive marijuana use compared with non-marijuana/non-tobacco use had statistically significantly higher mean cadmium levels in blood [ (95% CI: 1.11, 1.34); ] and urine [ (95% CI: 1.0, 1.31); ] and statistically significantly higher mean lead levels in blood [ (95% CI: 1.07, 1.50); ] and urine [ (95% CI: , 1.50); ]. Our results suggest marijuana is a source of cadmium and lead exposure. Research regarding cannabis use and cannabis contaminants, particularly metals, should be conducted to address public health concerns related to the growing number of cannabis users. https://doi.org/10.1289/EHP12074.

Blood Cadmium and Abdominal Aortic Calcification in Population with Different Weight Statuses: a Population-Based Study.

The aim of our study was to assess the effect of blood cadmium levels (B-Cd) on abdominal aortic calcification (AAC). We used the data from the 2013-2014 NHANES database. A total of 1530 participants were included in our study, with a mean AAC score of 1.40 ± 0.10, and a prevalence of severe AAC of 7.98%. Participants with higher B-Cd quartiles showed a higher prevalence of severe AAC. B-Cd was positively associated with higher AAC scores and increased risk of severe AAC. In the obese population, blood cadmium levels showed a positive association with the risk of severe AAC. There may be a positive correlation between B-Cd levels and AAC scores and risk of severe AAC, and this correlation is more pronounced in the obese population. Therefore, the cadmium load in AAC patients in the obese population should be considered in clinical work.

Association of blood cadmium and lead levels with self-reported reproductive lifespan and pregnancy loss: The national health and nutrition examination survey 1999–2018

Cadmium and lead are known to interfere with the endocrine function. Thus, hormonally regulated processes such as menarche, menopause and pregnancy are likely influenced by chronic exposure to these metals. In US post-menopausal women, who already completed their reproductive lifespan, we evaluated the association between blood cadmium and lead levels with self-reported reproductive lifespan and personal history of pregnancy loss. We selected 5317 post-menopausal women participating in the National Health and Nutrition Examination Survey (NHANES), 1999–2018. Blood cadmium and lead levels were measured by inductively coupled plasma mass spectrometry. Reproductive lifespan was defined as the number of years between self-reported age at menarche and menopause. Personal history of pregnancy loss was defined as number of self-reported pregnancy losses out of the self-reported number of pregnancies. The fully adjusted mean difference in reproductive lifespan (95% confidence interval [CI]) comparing the 80th to the 20th percentiles of blood cadmium and lead distributions was, respectively, 0.50 (0.10, 0.91) and 0.72 (0.41, 1.03) years. Ever smoker showed stronger association of blood lead with reproductive lifespan. For self-reported pregnancy loss, the corresponding fully adjusted relative prevalence (95% CI) was 1.10 (0.93, 1.31) for cadmium and 1.10 (1.00, 1.21) for lead, and remained similar after additional adjustment for reproductive lifespan. In never smokers, the relative prevalence was 1.07 (1.04, 1.11) and 1.16 (1.05, 1.28) for blood cadmium and lead, respectively. These findings suggest that blood cadmium and lead exposures increase reproductive lifespan and prevalence of pregnancy loss in the general population. Additional studies are needed to improve the understanding of mechanisms and prevention potential of metals-related pregnancy outcomes.

Effect of cadmium exposure on body composition deterioration: A propensity score-matched cohort study.

This propensity score-matched cohort study investigated the effects of blood cadmium (Cd) levels on body composition. Body composition was assessed by multifrequency bioelectrical impedance analysis and categorized into three groups: metabolically healthy obesity (MHO), adiposity obesity (AO), and sarcopenic obesity (SO). At baseline, 85 and 101 participants had MHO and AO, respectively (mean age, 51 ± 7years; male-to-female ratio, 1.0:1.3). During the 14-year follow-up, the body composition of 40 MHO and 6 AO participants deteriorated to AO and SO, respectively. The incidence of AO and SO differed according to age, sex, and blood Cd level. High blood Cd level increased the risk of body composition deterioration, particularly among those aged 60-69years (hazard ratio [HR] = 2.14), women (HR = 1.46), and those with AO at baseline (HR = 1.63; all p < 0.05). Cd exposure deteriorates body composition in older and female individuals, particularly from AO to SO.

Impact of dietary education on blood cadmium and mercury levels in chronic kidney disease: a path to renal health improvement

Impact of dietary education on blood cadmium and mercury levels in chronic kidney disease: a path to renal health improvement

Environmental risk factors of systemic lupus erythematosus: a case–control study

Systemic lupus erythematosus (SLE) is a complicated chronic autoimmune disorder. Several genetic and environmental factors were suggested to be implicated in its pathogenesis. The main objective of this study was to examine how exposure to selected environmental factors was associated with SLE risk to support the development of disease preventive strategies. A case–control study was conducted at the Rheumatology outpatient clinic of Alexandria Main University Hospital, in Alexandria, Egypt. The study sample consisted of 29 female SLE patients, and 27 healthy female controls, who matched the cases on age and parity. Data were collected by a structured interviewing questionnaire. Blood levels of lead, cadmium, and zinc of all participants were assessed by flame atomic absorption spectrometry. The multivariate stepwise logistic regression model revealed that five factors showed significant association with SLE, namely living near agricultural areas, passive smoking, blood lead levels ≥ 0.075 mg/L, and exposure to sunlight (odds ratio (OR) 58.556, 95% confidence interval (CI) 1.897–1807.759, OR 24.116, 95% CI 1.763–329.799, OR 18.981, 95% CI 1.228–293.364, OR 9.549, 95% CI 1.299–70.224, respectively). Whereas walking or doing exercise were significantly protective factors (P = 0.006). The findings of this study add to the evidence that SLE can be environmentally induced. Preventive measures should be taken to address the environmental risk factors of SLE.

Lead (Pb) and cadmium (Cd) blood levels and potential hematological health risk among inhabitants of the claimed hazardous region around Qaroun Lake in Egypt

BackgroundLead (Pb) and cadmium (Cd) heavy metals are considered potentially hazardous toxins which cause serious health problems. Many studies reported that the water of Qaroun Lake in Fayoum, Egypt with its fish farms was contaminated with Pb and Cd above permissible levels. However, there is a lack of studies addressing levels of these toxic metals among inhabitants.ObjectivesWe aimed to evaluate blood levels of Pb and Cd and their potential health risk among inhabitants around Qaroun Lake.Materials and methodsThis case-control study estimated Pb and Cd blood levels among 190 individuals from two destinations (near and far away) of Qaroun Lack using an atomic absorption spectrometer after full history taking and routine checkup investigations; Full blood count, serum ferritin, liver enzyme (ALT), and creatinine levels.ResultsThere was a significant difference between blood levels of Pb and Cd heavy metals of inhabitants from near and far away Qaroun Lake destinations (p-value < 0.001). The majority of inhabitants around Qaroun Lake had Pb and Cd blood levels above permissible levels (100% and 60% respectively). Critical levels out of them were 12.1% and 30.3% respectively. In comparison to inhabitants faraway Qaroun Lake, three individuals (2.4%) had Cd above the permissible level, while all of them (100%) had Pb level within the permissible level. There were no statistically significant differences between the two sampled populations as regards hemoglobin level, ALT, creatinine, and ferritin serum levels (p-value > 0.05). The difference between studied populations regarding types of anemia was not statistically significant. Subclinical leucopenia was higher in the population near Qaroun Lake when compare to inhabitants far from the lake (13.6% vs. 4.8%, p-value 0.032).ConclusionBio-monitoring of populations exposed to Pb and Cd hazardous substances could help in generating an early warning system to reduce the disease burden associated with their toxicity.

Global DNA methylation and the association between metal exposure and chronic kidney disease.

Prior studies indicate that exposure to metals may alter DNA methylation. Evidence also shows that global DNA methylation is associated with chronic kidney disease (CKD). This study aimed to examine the association between CKD and 5-methyl-2-deoxycytidine (5mdC, %), a marker of global DNA methylation, and to evaluate the interaction between metal exposures and 5mdC (%) on CKD. We also explored the mediation effect of 5mdC (%) on the association between metal exposures and renal function (i.e., estimated glomerular filtration rate, eGFR). A total of 218 CKD patients and 422 controls were recruited in this case-control study. 5mdC (%), concentrations of blood lead and cadmium, plasma selenium, and total urinary arsenic were measured. CKD cases were clinically defined among patients with eGFR <60 mL/min/1.73 m2 for at least 3 months and without hemodialysis. Odds ratio (OR) and 95% confidence interval (CI) were estimated by logistic regression models to examine the association between metal exposures, 5mdC (%), and CKD, adjusted for confounders. Multivariable linear regression models were used to examine associations between metal exposures, 5mdC (%), and eGFR. CKD cases compared to controls had 6.06-fold (95% CI: 3.11-11.81) higher odds of having high blood cadmium and high 5mdC (%) levels. A positive interaction on an additive scale was identified between blood cadmium and 5mdC (%) on CKD. Cases compared to controls had 4.73-fold (95% CI: 2.65-8.45) higher odds of having low plasma selenium and high 5mdC (%) levels; and a significant multiplicative interaction between plasma selenium and 5mdC (%) on CKD was observed. In addition, we found that blood lead and cadmium concentrations were positively associated, while plasma selenium concentrations were inversely associated, with 5mdC (%). The associations of blood lead and plasma selenium with eGFR were partially mediated by 5mdC (%). Our results suggest that 5mdC (%) may interact with plasma selenium and blood cadmium to influence the risk of CKD. The 5mdC (%) also potentially mediates the associations between exposure to metals and renal function.