Environmental and Occupational Exposures in Kidney Disease

Association of Metal Exposure with Novel Immunoinflammatory Indicators

Objective: We aimed to investigate the relationship between metal exposure and novel immunoinflammatory indicators. Methods: Data on adults participating in the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2018 were analyzed. Various statistical models were employed to assess the association between metal exposure and novel immune-inflammation-related indicators. Additionally, the impact of metal exposure on inflammation in different gender populations was explored. Results: This study included 4482 participants, of whom 51.1% were male. Significant correlations were observed among various metals. Both elastic net (ENET) and linear regression models revealed robust associations between cadmium (Cd), cobalt (Co), arsenic (As), mercury (Hg), and immunoinflammatory indicators. Weighted quantile sum (WQS) and Quantile g-computation (Q-gcomp) models demonstrated strong associations between barium (Ba), Co, and Hg and immunoinflammatory indicators. Bayesian kernel machine regression (BKMR) analysis indicated an overall positive correlation between in vivo urinary metal levels and systemic inflammation response index (SIRI) and aggregate index of systemic inflammation (AISI). Furthermore, Co, As, and Hg emerged as key metals contributing to changes in novel immunoinflammatory indicators. Conclusions: Metals exhibit associations with emerging immunoinflammatory indicators, and concurrent exposure to mixed metals may exacerbate the inflammatory response. Furthermore, this relationship varies across gender populations.

Renal tubular dysfunction in greenhouse farmers exposed to pesticides unveiled by a panel of molecular biomarkers of kidney injury

Growing evidence suggests that chronic exposure to pesticides may cause adverse effects on the health of the exposed population leading to organ-specific toxicity, including kidney damage. Traditional markers used to assess renal function (glomerular filtration rate (GFR), and serum creatinine and cystatin C -Cys-C-) are inadequate to evaluate a potential subclinical renal impairment linked to occupational exposure to pesticides, since levels above the upper limit of normal only occur when renal damage is very extensive. The use of more sensitive biomarkers is therefore needed. This study investigated novel urinary biomarkers of kidney function (microalbuminuria, osteopontin (OPN), trefoil factor 3 (TFF3), β-2-microglobulin, neutrophil gelatinase-associated lipocalin (NGAL), and Cys-C), together with the aforementioned traditional serum biomarkers, to assess potential kidney damage in farmers exposed to pesticides in an intensive agriculture setting. The study population consisted of 175 greenhouse workers and 91 healthy control subjects from Almeria (Southeastern Spain), a major hub of greenhouse agriculture. Data were collected at two different time-points of the same crop season: a period with greater pesticide use (high exposure period) and another with lower pesticide use (low exposure period). Significantly higher urinary levels of OPN and TFF3 were found in greenhouse workers than in controls, and in the high pesticide exposure period compared to that of low exposure. These changes suggest a subclinical tubular damage linked to pesticide exposure. In contrast, microalbuminuria, GFR, serum creatinine and Cys-C failed to be associated with pesticide exposure, suggesting that glomerular function was spared. Increased OPN and TFF3 levels over time may suggest a gradual progression from tubular dysfunction to chronic kidney disease in the exposed population.

Pollutants in aquatic system: a frontier perspective of emerging threat and strategies to solve the crisis for safe drinking water

Water is an indispensable natural resource and is the most vital substance for the existence of life on earth. However, due to anthropogenic activities, it is being polluted at an alarming rate which has led to serious concern about water shortage across the world. Moreover, toxic contaminants released into water bodies from various industrial and domestic activities negatively affect aquatic and terrestrial organisms and cause serious diseases such as cancer, renal problems, gastroenteritis, diarrhea, and nausea in humans. Therefore, water treatments that can eliminate toxins are very crucial. Unfortunately, pollution treatment remains a difficulty when four broad considerations are taken into account: effectiveness, reusability, environmental friendliness, and affordability. In this situation, protecting water from contamination or creating affordable remedial techniques has become a serious issue. Although traditional wastewater treatment technologies have existed since antiquity, they are both expensive and inefficient. Nowadays, advanced sustainable technical approaches are being created to replace traditional wastewater treatment processes. The present study reviews the sources, toxicity, and possible remediation techniques of the water contaminants.

Structural and Psychosocial Challenges Among Underserved Patients Receiving Hemodialysis During and Beyond the COVID-19 Pandemic: A Qualitative Study

Rationale & Objective

Racial and ethnic minority groups in the United States are disproportionately affected by chronic kidney disease and progressive kidney failure and face significantly more socioeconomic and psychosocial challenges. However, how such patients' social environment and stigmatization shape their illness experiences and abilities to cope before and during the coronavirus disease 2019 (COVID-19) pandemic has not been well documented, even as social scientific research predicts these groups' exponential vulnerability.

Study Design

Qualitative study using semistructured interviews to elicit individual patient narratives about their personal illness experiences before and during the COVID-19 pandemic, any challenges they faced, and their sources of support.

Setting & Participants

Using purposive sampling, we recruited 20 adult patients receiving maintenance hemodialysis from centers affiliated with a safety-net hospital in Boston, Massachusetts.

Analytical Approach

Interviews were audiotaped, transcribed, and analyzed using thematic content analysis to identify patients' challenges and supports before and during the pandemic.

Results

Of the 20 patients in the study, 9 were women, and 18 self-identified as Black or African American. Three main themes emerged, whereby most patients described: (1) stigma and stigmatization as a central element of their life experience; (2) the pandemic as a difficult experience but not a complete rupture from their prepandemic life; and (3) social networks, particularly family, friends, and religious communities, as sources of support crucial to coping with their debilitating illness.

Limitations

Whether the findings apply to other settings is unknown, as participants were recruited from centers in a single safety-net urban hospital setting.

Conclusions

Psychosocial and environmental factors, including institutional racism and stigmatization, play significant roles in amplifying the burdens shouldered by racial and ethnic minority individuals with kidney disease who now also face the COVID-19 pandemic that has since turned endemic. The results of this study can inform the development of policy interventions aimed at alleviating tensions and structural conditions that impinge on kidney disease patients' wellbeing and health outcomes.

Plain-Language Summary

Members of racial and ethnic minority groups in the United States experience the highest rates of progressive kidney failure and face significantly more socioeconomic and psychosocial challenges. We interviewed 20 patients who receive maintenance hemodialysis treatment from centers affiliated with a safety-net hospital. Patients described stigmatization as a central element of their life experience and the pandemic as a difficult challenge (but not a complete rupture) that added to their struggles with illness-related, race-related, and class-related stigmas. Social networks, particularly family, friends, and religious communities, are key sources of support crucial to coping with illness. Findings from this study can inform health care providers and community workers and guide the development of policy interventions to provide better support for these patients.

A State-of-the-Science Review on Metal Biomarkers

PURPOSE OF REVIEW

Biomarkers are commonly used in epidemiological studies to assess metals and metalloid exposure and estimate internal dose, as they integrate multiple sources and routes of exposure. Researchers are increasingly using multi-metal panels and innovative statistical methods to understand how exposure to real-world metal mixtures affects human health. Metals have both common and unique sources and routes of exposure, as well as biotransformation and elimination pathways. The development of multi-element analytical technology allows researchers to examine a broad spectrum of metals in their studies; however, their interpretation is complex as they can reflect different windows of exposure and several biomarkers have critical limitations. This review elaborates on more than 500 scientific publications to discuss major sources of exposure, biotransformation and elimination, and biomarkers of exposure and internal dose for 12 metals/metalloids, including 8 non-essential elements (arsenic, barium, cadmium, lead, mercury, nickel, tin, uranium) and 4 essential elements (manganese, molybdenum, selenium, and zinc) commonly used in multi-element analyses.

RECENT FINDINGS

We conclude that not all metal biomarkers are adequate measures of exposure and that understanding the metabolic biotransformation and elimination of metals is key to metal biomarker interpretation. For example, whole blood is a good biomarker of exposure to arsenic, cadmium, lead, mercury, and tin, but it is not a good indicator for barium, nickel, and uranium. For some essential metals, the interpretation of whole blood biomarkers is unclear. Urine is the most commonly used biomarker of exposure across metals but it should not be used to assess lead exposure. Essential metals such as zinc and manganese are tightly regulated by homeostatic processes; thus, elevated levels in urine may reflect body loss and metabolic processes rather than excess exposure. Total urinary arsenic may reflect exposure to both organic and inorganic arsenic, thus, arsenic speciation and adjustment for arsebonetaine are needed in populations with dietary seafood consumption. Hair and nails primarily reflect exposure to organic mercury, except in populations exposed to high levels of inorganic mercury such as in occupational and environmental settings. When selecting biomarkers, it is also critical to consider the exposure window of interest. Most populations are chronically exposed to metals in the low-to-moderate range, yet many biomarkers reflect recent exposures. Toenails are emerging biomarkers in this regard. They are reliable biomarkers of long-term exposure for arsenic, mercury, manganese, and selenium. However, more research is needed to understand the role of nails as a biomarker of exposure to other metals. Similarly, teeth are increasingly used to assess lifelong exposures to several essential and non-essential metals such as lead, including during the prenatal window. As metals epidemiology moves towards embracing a multi-metal/mixtures approach and expanding metal panels to include less commonly studied metals, it is important for researchers to have a strong knowledge base about the metal biomarkers included in their research. This review aims to aid metals researchers in their analysis planning, facilitate sound analytical decision-making, as well as appropriate understanding and interpretation of results.

Structural Racism, Historical Redlining, and Incidence of Kidney Failure in US Cities, 2012-2019

SIGNIFICANCE STATEMENT

Residing in neighborhoods designated as grade D (hazardous) by the Home Owners' Loan Corporation (HOLC) under historical redlining-a discriminatory housing policy beginning in the 1930s-has been associated with present-day adverse health outcomes such as diabetes mortality. Historical redlining might underlie conditions in present-day neighborhoods that contribute to inequitable rates of kidney failure incidence, particularly for Black individuals, but its association with kidney disease is unknown. The authors found that among adults with incident kidney failure living in 141 metropolitan areas, residence in a historically redlined neighborhood rated grade D was associated with significantly higher kidney failure incidence rates compared with residence in a redlined grade A (best) neighborhood. These findings suggest that historical racist policies continue to affect current-day racial inequities in kidney health.

BACKGROUND

Historical redlining was a 1930s federally sponsored housing policy that permitted the Home Owners' Loan Corporation (HOLC) to develop color-coded maps and grade neighborhoods' mortgage lending risk on the basis of characteristics that included racial makeup. This practice has been associated with present-day health disparities. Racial inequities in kidney disease-particularly for Black individuals-have been linked to residential segregation and other structural inequities.

METHODS

Using a registry of people with incident kidney failure and digitized HOLC maps, we examined the association between residence in a historically redlined US census tract (CT) with a historical HOLC grade of D or hazardous) and present-day annual CT-level incidence of kidney failure incidence among adults in 141 US metropolitan areas, in 2012 through 2019.

RESULTS

Age-adjusted and sex-adjusted kidney failure incidence rates were significantly higher in CTs with a historical HOLC grade D compared with CTs with a historical HOLC grade of A or best (mean, 740.7 per million versus 326.5 per million, respectively, a difference of 414.1 per million). Compared with national averages of all adults in our sample, rates of kidney failure incidence were higher for Black adults in our study sample, irrespective of CT HOLC grade. Age-adjusted and sex-adjusted incidence rates for Black persons in CTs with a HOLC grade D were significantly higher than for Black persons residing in HOLC grade A CTs (mean, 1227.1 per million versus 1030.5 per million, respectively [a difference of 196.6 per million]).

CONCLUSIONS

Historical redlining is associated with present-day disparities in kidney failure incidence, demonstrating the legacy of historical racist policies on contemporary racial inequities in kidney health.

PODCAST

This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/JASN/2023_08_24_JASN0000000000000165.mp3.

Current Levels of Environmental Exposure to Cadmium in Industrialized Countries as a Risk Factor for Kidney Damage in the General Population: A Comprehensive Review of Available Data

The growing number of reports indicating unfavorable outcomes for human health upon environmental exposure to cadmium (Cd) have focused attention on the threat to the general population posed by this heavy metal. The kidney is a target organ during chronic Cd intoxication. The aim of this article was to critically review the available literature on the impact of the current levels of environmental exposure to this xenobiotic in industrialized countries on the kidney, and to evaluate the associated risk of organ damage, including chronic kidney disease (CKD). Based on a comprehensive review of the available data, we recognized that the observed adverse effect levels (NOAELs) of Cd concentration in the blood and urine for clinically relevant kidney damage (glomerular dysfunction) are 0.18 μg/L and 0.27 μg/g creatinine, respectively, whereas the lowest observed adverse effect levels (LOAELs) are >0.18 μg/L and >0.27 μg/g creatinine, respectively, which are within the lower range of concentrations noted in inhabitants of industrialized countries. In conclusion, the current levels of environmental exposure to Cd may increase the risk of clinically relevant kidney damage, resulting in, or at least contributing to, the development of CKD.

Association between social jetlag and chronic kidney disease among the Korean working population

Social jetlag refers to the discrepancy between social time and the body's internal rhythm, which can lead to unfavorable health outcomes. However, no study has directly explored the relation between social jetlag and chronic kidney disease (CKD). This study aims to investigate the relationship between social jetlag and CKD in a representative population of South Korea. This study included 8259 currently economically active Korean population in the Korea National Health and Nutrition Examination Survey. Social jetlag was calculated as the difference between the midpoint of sleep time on weekdays and free days. The estimated glomerular filtration rate (eGFR) was calculated the by using the serum creatinine value according to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Participants with an eGFR less than 60 ml/min/1.73 m² were defined as CKD cases. The estimated glomerular filtration rate decreased as social jetlag increased. Multiple logistic regression analysis showed that the adjusted odds ratio (95% confidence interval) of CKD for 1-2 h of social jetlag was 0.926 (0.660-1.299), while the odds ratio for more than 2 h was 2.042 (1.328-3.139) when less than 1 h was used as reference. This study found that social jetlag and risk of CKD were significantly related in the Korean working population.

Association of exposure to multiple serum metals with the risk of chronic kidney disease in the elderly: a population-based case-control study

In the world, chronic kidney disease (CKD) has been recognized as one of the critical public health problems, and the prevalence is higher in the elderly people. However, there are few studies on the association between exposure to multiple serum metal levels and CKD. A case-control study, we established, for elderly people in Anhui Province, China, to explore the effects of different metals and analyze the effect of mixed exposure on CKD. In this study, 287 cases of CKD and 287 controls were selected in the elderly health physical examination project in Tongling City, Anhui Province. Questionnaire survey, physical examination, and blood collection were conducted. Graphite furnace atomic absorption spectrometry (GFAAS) and inductively coupled plasma optical emission spectrometry (ICP-OES) were used to measure the concentration of serum metals. After selecting by least absolute shrinkage and selection operator (LASSO), 5 metals were brought into the multi-metal model. After adjusting all potential covariates additionally, the concentrations of lead (Pb), cadmium (Cd), cobalt (Co), and manganese (Mn) were significantly associated with CKD risk, whereas Pb, Se, and Cd had significant non-linearity with CKD. Besides, patients with highest quartiles of cobalt (Co), lead (Pb), and manganese (Mn) were 1.64, 1.39, and 0.64 times more possible to have CKD, respectively, as compared with the lowest levels. In the Bayesian kernel machine regression (BKMR) model, cadmium (Cd) had a combined effect with lead (Pb) possibly. This study suggested that the CKD risk was associated with exposure of multiple metals in elderly people. The underlying mechanisms of serum metals and CKD need more experimental and prospective studies to elucidate.

Where do you live and what do you do? Two questions that might impact your kidney health

In many cases the social determinants of health need to be assessed through their interaction with environmental factors. This review looks at the impact of physical location and occupation of individuals on their kidney health. It examines the effect of living at high altitude on kidney function and the relationship between extreme cold or hot temperatures and the incidence of kidney injury. It reviews as well the many occupations that have been linked to kidney disease in high-income and low-and-middle-income countries. As a conclusion, this overview proposes preventive recommendations that could be individualized based on weather, altitude, socio-economic level of the country and occupation of the individual.

The Effect of Polyphenols on Kidney Disease: Targeting Mitochondria

Mitochondrial function, including oxidative phosphorylation (OXPHOS), mitochondrial biogenesis, and mitochondria dynamics, are essential for the maintenance of renal health. Through modulation of mitochondrial function, the kidneys are able to sustain or recover acute kidney injury (AKI), chronic kidney disease (CKD), nephrotoxicity, nephropathy, and ischemia perfusion. Therapeutic improvement in mitochondrial function in the kidneys is related to the regulation of adenosine triphosphate (ATP) production, free radicals scavenging, decline in apoptosis, and inflammation. Dietary antioxidants, notably polyphenols present in fruits, vegetables, and plants, have attracted attention as effective dietary and pharmacological interventions. Considerable evidence shows that polyphenols protect against mitochondrial damage in different experimental models of kidney disease. Mechanistically, polyphenols regulate the mitochondrial redox status, apoptosis, and multiple intercellular signaling pathways. Therefore, this review attempts to focus on the role of polyphenols in the prevention or treatment of kidney disease and explore the molecular mechanisms associated with their pharmacological activity.

High prevalence of chronic kidney disease of unknown etiology among workers in the Mesoamerican Nephropathy Occupational Study

BACKGROUND

Mortality from chronic kidney disease of unknown etiology (CKDu) is extremely high along the Pacific coast of Central America, particularly among sugarcane workers. The Mesoamerican Nephropathy Occupational Study (MANOS) is a prospective cohort study of CKDu among agricultural and non-agricultural workers in El Salvador and Nicaragua. The objective of this manuscript is to describe the MANOS cohort recruitment, baseline data collection, and CKDu prevalence after two rounds.

METHODS

Workers with no known diabetes, hypertension, or CKD were recruited from sugarcane, corn, plantain, brickmaking, and road construction industries (n = 569). Investigators administered questionnaires, collected biological samples, and observed workers for three consecutive workdays at the worksite. Serum specimens were analyzed for kidney function parameters, and used to calculate estimated glomerular filtration rate (eGFR). At six months, serum was collected again prior to the work shift. CKD at baseline is defined as eGFR ≤ 60 ml/min/1.73m² at both timepoints. Age-standardized prevalence was calculated by industry, country, and demographic measures. Kidney function parameters were compared by CKD status.

RESULTS

Prevalence of CKD at baseline was 7.4% (n = 42). Age-standardized prevalence was highest in Salvadoran sugarcane (14.1%), followed by Salvadoran corn (11.6%), and Nicaraguan brickmaking (8.1%). Nicaraguan sugarcane had the lowest prevalence, likely due to kidney function screenings prior to employment.

CONCLUSION

Despite efforts to enroll participants without CKD, our identification of prevalent CKD among agricultural and non-agricultural workers in the MANOS cohort indicates notable kidney disease in the region, particularly among sugarcane workers.

Analysis of Threshold Effect of Urinary Heavy Metal Elements on the High Prevalence of Nephrolithiasis in Men

Exposure to heavy metals in the environment exerts serious effects on kidney health. However, the effects of joint exposure on the kidneys have been rarely studied, particularly in non-occupational exposure high-risk populations. This study provided a reference threshold range of heavy metals in urine and explored the effect of joint exposure on nephrolithiasis in men. The data were obtained from the China Multi-Ethnic Cohort database, and 1502 men were included in the study. A two-piece-wise regression model was used to assess the dose-response relationship between heavy metal exposure and nephrolithiasis. The least absolute shrinkage and selection operator regression model was used to calculate the score of joint exposure to heavy metals. The threshold effect analysis revealed a linear relationship between the concentration of arsenic (As) in the urine and the prevalence of nephrolithiasis, whereas a nonlinear relationship was observed with cadmium (Cd), chromium (Cr), mercury (Hg), and lead (Pb). In addition, As, Cd, Cr, Hg, and Pb may significantly affect the joint exposure effect. Moreover, the final risk of nephrolithiasis increased by 123% (P for trend < 0.001). This study found a threshold relationship between heavy metals (Cd, Cr, Hg, Pb) in male urine and the occurrence of nephrolithiasis. Joint exposure to heavy metals in urine caused a high-risk effect on nephrolithiasis. The study provided a reference threshold value of related studies and indicated that environmental pollution caused by heavy metals should be reduced.

Longitudinal assessment of kidney function in migrant farm workers

Chronic kidney disease of unknown etiology (CKDu) is an epidemic that affects young agricultural workers in several warm regions of the world. However, there is a lack of monitoring of kidney issues in regions with extremely warm environments such as the Northwest of Mexico, a semi-arid region with a growing agricultural industry, where migrant and seasonal farm workers (MSFWs) travel to work in the fields. The objective of this study was to longitudinally assess kidney functioning of MSFWs in relation to pesticide exposure, heat stress and dehydration in a large-scale farm in Mexico. We enrolled 101 MSFWs, of whom 50 were randomly selected to work in an organic certified area and 51 were randomly selected to work in a conventional area. We also enrolled 50 office workers within the same region as a reference group. We collected urine and blood samples from all workers in addition to demographic, behavioral, and occupational characteristics. The physiological strain index (PSI) was used to estimate workers' heat strain. Sampling was conducted at pre-harvest (March) and late in the harvest (July). Linear mixed models were built with the estimated glomerular filtration rate (eGFR) as the dependent variable. We found a significant decrease in kidney function in MSFWs compared to office workers. By the late harvest, one MSFW developed kidney disease, two MSFWs suffered a kidney injury, and 14 MSFWs were at risk of a kidney injury. We found that the eGFR in MSFWs decreased significantly from pre-harvest (125 ± 13.0 mL/min/1.73 m²) to late harvest (109 ± 13.6 mL/min/1.73 m²) (p < 0.001), while no significant change was observed in office workers. The eGFR was significantly lower in MSFWs who worked in the conventional field (101.2 ± 19.4 mL/min/1.73 m²) vs the organic field (110.9 ± 13.6 mL/min/1.73 m²) (p = 0.002). In our final model, we found that dehydration was associated with the decrease of eGFR. We also found an interaction between heat strain and job category, as a significant decline in eGFR by job category (conventional/organic MSFWs and office workers) was related to an increase in heat strain. This suggests that pesticide exposure needs to be considered in combination with heat stress and dehydration. This study provides valuable information on kidney function in MSFWs, and it shows the importance of early long-term monitoring in farm workers in other regions where CKDu has not been evaluated yet.

Farmers' Knowledge, Attitudes, and Perceptions Regarding Carcinogenic Pesticides in Fez Meknes Region (Morocco)

Pesticides play an important role in the improvement of agricultural production, but their use may result in adverse effects on the environment, consumers, and farmers’ health. As there are limited data focusing on the factors influencing safety behavior toward pesticide use in Morocco, we conducted a cross-sectional survey in 15 rural communities of Morocco’s Fes Meknes region to assess the attitudes, knowledge, and practices regarding pesticide use. A structured questionnaire was completed, containing the data of the interviewed farmers, their behavior towards safety measures, the type of active ingredient used, as well as the perception of risks to their own health following exposure to pesticides by the existence of chronic, self-perceived symptoms. Non-probability (empirical) sampling with the quota method was carried out, which consists of constructing the sample. Results showed that most respondents have not been trained in the application of pesticides, with almost half of the farmers using a category of pesticides which are classified by the International Agency for Research on Cancer as probable human carcinogenic (i.e., Glyphosate, Malathion). In terms of pesticide storage, 40% of farmers said that they did not store pesticides in a separate room after purchasing or using them. The empty containers were buried or burnt by half of the responders, while the remainder were thrown at the edge of fields or in public dumps. Although the participants were aware of the negative effects on their own health and on the environment caused by the application of pesticides in use, the protection measures by individual equipment were insufficient. A canonical analysis indicates that these behaviors were influenced by the farming experience, the benefit of the agricultural council services, the follow-up of training, and the education level. These variables are important factors in explaining and understanding the dangers to both the environment and health caused by pesticides. The most recorded likely consequences of pesticide exposure were visual impairment (46%), followed by dizziness (44.3%), headache (39.4%), and excessive sweating (34.4%), and 30.2% of participants identified consequent respiratory problems. Extension services targeted at safety and protection measures should be developed and accompanied by educational programs to put farmers’ perceptions into practice and encourage them to adopt healthy and environmentally friendly behaviors.

Global Epidemiology of End-Stage Kidney Disease and Disparities in Kidney Replacement Therapy

BACKGROUND

The global epidemiology of end-stage kidney disease (ESKD) reflects each nation's unique genetic, environmental, lifestyle, and sociodemographic characteristics. The response to ESKD, particularly regarding kidney replacement therapy (KRT), depends on local disease burden, culture, and socioeconomics. Here, we explore geographic variation and global trends in ESKD incidence and prevalence and examine variations in KRT modality, practice patterns, and mortality. We conclude with a discussion on disparities in access to KRT and strategies to reduce ESKD global burden and to improve access to treatment in low- and middle-income countries (LMICs).

SUMMARY

From 2003 to 2016, incidence rates of treated ESKD were relatively stable in many higher income countries but rose substantially predominantly in East and Southeast Asia. The prevalence of treated ESKD has increased worldwide, likely due to improving ESKD survival, population demographic shifts, higher prevalence of ESKD risk factors, and increasing KRT access in countries with growing economies. Unadjusted 5-year survival of ESKD patients on KRT was 41% in the USA, 48% in Europe, and 60% in Japan. Dialysis is the predominant KRT in most countries, with hemodialysis being the most common modality. Variations in dialysis practice patterns account for some of the differences in survival outcomes globally. Worldwide, there is a greater prevalence of KRT at higher income levels, and the number of people who die prematurely because of lack of KRT access is estimated at up to 3 times higher than the number who receive treatment. Key Messages: Many people worldwide in need of KRT as a life-sustaining treatment do not receive it, mostly in LMICs where health care resources are severely limited. This large treatment gap demands a focus on population-based prevention strategies and development of affordable and cost-effective KRT. Achieving global equity in KRT access will require concerted efforts in advocating effective public policy, health care delivery, workforce capacity, education, research, and support from the government, private sector, nongovernmental, and professional organizations.

Associations among Heavy Metals and Proteinuria and Chronic Kidney Disease

Background: The prevalence of chronic kidney disease (CKD) is increasing annually in Taiwan. In addition to traditional risk factors, heavy metals contribute to the development of CKD. The aim of this study was to investigate associations among heavy metals and proteinuria and CKD in the general population in Southern Taiwan. We also explored the interaction and synergetic effects among heavy metals on proteinuria. Methods: We conducted a health survey in the general population living in Southern Taiwan between June 2016 and September 2018. Seven heavy metals were measured: blood lead (Pb) and urine nickel (Ni), chromium (Cr), manganese (Mn), arsenic (As), copper (Cu), and cadmium (Cd). Proteinuria was measured using reagent strips. CKD was defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m². Results: The mean age of the 2447 participants was 55.1 ± 13.2 years and included 977 males and 1470 females. Participants with high blood Pb and high urine Ni, Mn, Cu, and Cd were significantly associated with proteinuria. Interactions between blood Pb and urine Cr, and between urine Cd and Cu, had significant effects on proteinuria. The participants with high blood Pb and high urine Cu were significantly associated with an eGFR of <60 mL/min/1.73 m². Conclusion: High blood Pb and high urine Cu may be associated with proteinuria and an eGFR of <60 mL/min/1.73 m². High urine Ni, Mn, and Cd were significantly associated with proteinuria. Co-exposure to Cd and Cu, and Pb and Cr, may have synergistic effects on proteinuria.

Environmental Pollution and Chronic Kidney Disease

Chronic kidney disease (CKD) is a global public health problem associated with high rates of morbidity and mortality due to end-stage renal disease and cardiovascular disease. Safe and effective medications to reverse or stabilize renal function in patients with CKD are lacking, and hence it is important to identify modifiable risk factors associated with worsening kidney function. Environmental pollutants, including metals, air pollutant, phthalate and melamine can potentially increase the risk of CKD or accelerate its progression. In this review, we discuss the epidemiological evidence for the association between environmental pollution and kidney disease, including heavy metals, air pollution and other environmental nephrotoxicants in the general population.

Genitourinary Systems Entangled with Shifting Environments in a Salvadoran Subsistence Farming Community

Diseases of the genitourinary system are the leading cause of hospital deaths in El Salvador, and chronic kidney disease of unknown origin has been gaining attention as a public health problem among farmers in particular. Epidemiological studies point, in part, to environmental risk factors, which have shifted over time with the deployment of modern agricultural science and ongoing climate change. We examined how diseases of the genitourinary system were situated at several margins of an epidemic in one rural Salvadoran municipality where these environmental and epidemiological changes are occurring, albeit relatively slow. By using this approach to study diseases of the genitourinary system, we illustrate one way in which shifting human/environment entanglements can be experimentally "known" in the context of human diseases associated with them. Our approach offers a unique perspective in thinking with ethnographic data to compliment ongoing epidemiological investigations of kidney disease in El Salvador.

Organic diet intervention significantly reduces urinary glyphosate levels in U.S. children and adults

BACKGROUND

A growing set of studies show that an organic diet is associated with reduced levels of urinary pesticide analytes. However, with the exception of one pilot study of two individuals, diet intervention studies to date have not analyzed glyphosate, the most commonly used herbicide in the United States and globally.

OBJECTIVE

To investigate the impact of an organic diet intervention on levels of glyphosate and its main metabolite, AMPA (aminomethyl phosphonic acid), in urine collected from adults and children.

METHODS

We analyzed urine samples from four racially and geographically diverse families in the United States for five days on a completely non-organic diet and for five days on a completely organic diet (n = 16 participants and a total of 158 urine samples).

RESULTS

Mean urinary glyphosate levels for all subjects decreased 70.93% (95% CI -77.96, -61.65, p<0.010) while mean AMPA levels decreased by 76.71% (95% CI -81.54, -70.62, p < 0.010) within six days on an organic diet. Similar decreases in urinary levels of glyphosate and AMPA were observed when data for adults were examined alone, 71.59% (95% CI -82.87, -52.86, p < 0.01) and 83.53% (95% CI -88.42, -76.56, p < 0.01) and when data for children were examined alone, 70.85% (95% CI -78.52, -60.42, p < 0.01) and 69.85% (95% CI -77.56, -59.48, p < 0.01).

CONCLUSION

An organic diet was associated with significantly reduced urinary levels of glyphosate and AMPA. The reduction in glyphosate and AMPA levels was rapid, dropping to baseline within three days. This study demonstrates that diet is a primary source of glyphosate exposure and that shifting to an organic diet is an effective way to reduce body burden of glyphosate and its main metabolite, AMPA. This research adds to a growing body of literature indicating that an organic diet may reduce exposure to a range of pesticides in children and adults.

COVID-19, Racism, and Racial Disparities in Kidney Disease: Galvanizing the Kidney Community Response

PodcastThis article contains a podcast athttps://www.asn-online.org/media/podcast/JASN/2020_07_21_JASN2020060809.mp3.

Genetic and Developmental Factors in Chronic Kidney Disease Hotspots

Chronic kidney disease increasingly is being recognized as an important global public health problem. Interindividual susceptibility to kidney disease is high and likely is dependent on risk modulation through genetics, fetal and early childhood development, environmental circumstances, and comorbidities. Traditionally, the chronic kidney disease burden has been ascribed largely to hypertension and diabetes. Increasingly, evidence is accumulating that nontraditional risk factors may predominate in some regions and populations, contributing to epidemics of kidney disease. Such nontraditional risk factors include environmental exposures, traditional medicines, fetal and maternal factors, infections, kidney stones, and acute kidney injury. Genetic factors may predispose patients to chronic kidney disease in some populations. Chronic kidney disease of unknown origin has its epicenters in Central America and South Asia. Such clustering of CKD may represent either genetic or environmentally driven kidney disease, or combinations of both. Developmental conditions impacting kidney development often are related to poverty and structural factors that persist throughout life. In this article, we explore the possibilities that genetic and developmental factors may be important contributors to the epidemics in these regions and suggest that optimization of factors impacting kidney development hold promise to reduce the risk of kidney disease in future generations.

Longitudinal trends in renal function among first time sugarcane harvesters in Guatemala

Introduction

Chronic kidney disease of unknown origin (CKDu) is an epidemic concentrated in agricultural communities in Central and South America, including young, male sugarcane harvesters. The purpose of this analysis is to understand early changes in kidney function among a cohort of first-time sugarcane harvesters and to determine risk factors for kidney function decline.

Methods

Joint latent class mixed models were used to model sub-population kidney function trajectory over the course of 4 years (2012–2016). Probability weighted logistic regression was used to determine personal health, community, and individual behavior risk factors associated with sub-population assignment. Data analysis occurred in 2019.

Results

Of 181 new workers median age 19 years old (IQR: 4), 39 (22%) were identified as having non-stable kidney function with an annual age-adjusted decline of estimated glomerular filtration rate (eGFR) of -1.0 ml/min per 1.73 m² (95% CI: -3.4, 1.3). Kidney function (OR: 0.96; 95% CI: 0.93, 0.98), mild hypertension (OR: 5.21; 95% CI: 2.14, 13.94), and having a local home of residence (OR: 7.12; 95% CI: 2.41, 26.02) prior to employment in sugarcane were associated with non-stable eGFR sub-population assignment.

Conclusions

Mild hypertension may be an early indicator of the development of CKDu. A better understanding of preexisting risk factors is needed to determine why individuals are entering the workforce with reduced kidney function and elevated blood pressure and increased risk of renal function decline.

Subcellular Organelle Toxicity Caused by Arsenic Nanoparticles in Isolated Rat Hepatocytes

BACKGROUND

Arsenic, an environmental pollutant, is a carcinogenic metalloid and also an anticancer agent.

OBJECTIVE

To evaluate the toxicity of arsenic nanoparticles in rat hepatocytes.

METHODS

Freshly isolated rat hepatocytes were exposed to 0, 20, 40, and 100 μM of arsenic nanoparticles and its bulk counterpart. Their viability, reactive oxygen species level, glutathione depletion, mitochondrial and lysosomal damage, and apoptosis were evaluated.

RESULTS

By all concentrations, lysosomal damage and apoptosis were clearly evident in hepatocytes exposed to arsenic nanoparticles. Evaluation of mitochondria and lysosomes revealed that lysosomes were highly damaged.

CONCLUSION

Exposure to arsenic nanoparticles causes apoptosis and organelle impairment. The nanoparticles have potentially higher toxicity than the bulk arsenic. Lysosomes are highly affected. It seems that, instead of mitochondria, lysosomes are the first target organelles involved in the toxicity induced by arsenic nanoparticles.