Occupational risk factors for chronic kidney disease in Andhra Pradesh: 'Uddanam Nephropathy'

Green Dialysis From the Indian Perspective: A Systematic Review

Global warming and climate change represent the most significant threats to humanity in the 21st century, both of which are manmade catastrophes. Addressing climate change requires corrective action across all aspects of modern human life and work, including the medical field. Among healthcare sectors, dialysis units stand out as major contributors to plastic waste and excessive water consumption. It is imperative for hemodialysis units to lead by example in the judicious use of natural resources. This systemic review is aimed to establish a bare minimum of recommendations for environmental sustainability across Indian dialysis units, and to guide future initiatives to reduce the environmental impact of dialysis process. A literature search was conducted on PubMed, and Google to retrieve articles or studies related to green dialysis. The predefined keyword search yielded a total of 291 studies. A total of 54 studies and articles which were relevant to study question, and fulfilled inclusion criteria, were retrieved and analyzed to form opinions on the implementation of green dialysis initiatives from an Indian perspective. Green dialysis initiatives are much-needed reforms to be adopted by the Indian dialysis community. Through careful planning and minimal efforts, substantial amounts of water used in hemodialysis can be conserved and repurposed for other hospital activities. Similarly, the vast majority of discarded plastic waste can be recycled or reused. Despite controversy, reconsidering the risk-benefit aspects of dialyzer reuse is essential, particularly in the context of resource-limited developing nations like India.

Clinical findings and kidney morphology in chronic kidney disease of unknown cause in India

BACKGROUND

Chronic kidney disease of unknown cause (CKDu) is an emerging health problem in India and other countries worldwide. However, clinical descriptions, including kidney pathology, are scarce.

METHODS

This is a descriptive case series of patients with CKDu from an endemic region in India, with a focus on clinical and biochemical characteristics, kidney biopsy findings, and environmental exposure. Patients with suspected CKDu, aged 20-65, and eGFR 30-80 mL/min/1.73 m2 from rural areas with endemic prevalence of CKDu were included. The exclusion criteria were diabetes mellitus, uncontrolled hypertension, proteinuria >1 g/24 h, or other known kidney diseases. The participants underwent kidney biopsies, and blood and urine samples were collected.

RESULTS

Fourteen participants (3 females, 11 males) with a mean eGFR of 53 (range 29-78) mL/min/1.73 m2 were included. Kidney biopsies showed a combination of chronic tubulointerstitial damage, glomerulosclerosis, and glomerular hypertrophy, with varying degrees of interstitial inflammation. Eight participants had polyuria (diuresis ≥ 3 L/day). The urinary sediments were bland, with no haematuria. Serum potassium and sodium levels were, in most cases, normal but within the lower reference interval.

CONCLUSION

The kidney morphology and clinical characteristics in patients with CKDu in India were similar to those described for CKDu in Central America and Sri Lanka.

Climate change and nephrology

Climate change should be of special concern for the nephrologist, as the kidney has a critical role in protecting the host from dehydration, but it is also a favorite target of heat stress and dehydration. Here we discuss how rising temperatures and extreme heat events may affect the kidney. The most severe presentation of heat stress is heat stroke, which can result in severe electrolyte disturbance and both acute and chronic kidney disease (CKD). However, lesser levels of heat stress also have multiple effects, including exacerbating kidney disease and precipitating cardiovascular events in subjects with established kidney disease. Heat stress can also increase the risk for kidney stones, cause multiple electrolyte abnormalities and induce both acute and chronic kidney disease. Recently there have been multiple epidemics of CKD of uncertain etiology in various regions of the world, including Mesoamerica, Sri Lanka, India and Thailand. There is increasing evidence that climate change and heat stress may play a contributory role in these conditions, although other causes, including toxins, could also be involved. As climate change worsens, the nephrologist should prepare for an increase in diseases associated with heat stress and dehydration.

Mysterious Outbreak of Acute Neurological Syndrome in Eluru, Andhra Pradesh, India: A Post-outbreak Geo-Spatial Analysis

BACKGROUND

An outbreak characterized by sudden-onset seizures, loss of consciousness, and complete recovery within a few hours was reported from Eluru town in Andhra Pradesh on December 6, 2020. This study was conducted to assess the environmental correlates of the outbreak using geo-mapping tools.

METHODS

A post-outbreak survey was conducted among affected cases in January-February, 2021. A house-to-house survey tool collected information on demographics, clinical profile, and environmental and psychological aspects (Impact of Event Scale). Geo-mapping and news media content analyses were done using QGIS and Atlas.ti software, respectively.

RESULTS

A total of 394 cases were studied. The median (interquartile range [IQR]) age of the participants was 27 (17-39) years and comprised mostly male students. There was no clustering of cases within 48 hours of illness onset in the spatial analysis. Loss of consciousness was the first (50.7%) and the most common symptom. All cases were taken to a health facility and were discharged after a median duration of 48 minutes. COVID-19-related and environmental practices were not associated with the clinical manifestations. Awareness about pesticides was low. The outbreak reportedly had a psychological impact on 24.4% of the participants. The most common co-occurring themes in the news media analysis were water contamination and pesticides.

CONCLUSION

The geo-spatial analysis did not find case clustering or points of convergence during the incubation period. The geo-locations did not distribute around water bodies or suspected landmarks although news media projected water contamination and pesticides as probable causes of the outbreak.

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.

Inhaled Silica Nanoparticles Causes Chronic Kidney Disease in Rats

INTRODUCTION

Silica nanoparticles (SiNPs) released during the burning of sugarcane have been postulated to have a role in chronic kidney disease of unknown etiology. We tested the hypothesis that pristine SiNPs of the size present in sugarcane might cause chronic kidney injury when administered through the lung in rats.

METHODS

We administered 200 nm or 300 nm amorphous SiNPs twice weekly (4 mg/dose) or vehicle by oropharyngeal aspiration for 13 weeks to rats followed by sacrifice after an additional 13 weeks (26 weeks total). Tissues were evaluated for presence of SiNPs and evidence of histologic injury.

RESULTS

Both sizes of SiNPs caused kidney damage, with early tubular injury and inflammation (at week 13) that continued to inflammation and chronic fibrosis at week 26 despite discontinuing the SiNP administration. Both sizes of SiNPs caused local inflammation in the lung and kidney and were detected in the serum and urine at week 13, and the 200 nm particles also localized to the kidney with no evidence of retention of the 300 nm particles. At week 26 there was some clearance of the 200 nm silica from the kidneys, and urinary levels of SiNPs were reduced but still significant in both the 200 and 300 nm exposed rats.

CONCLUSIONS

Inhaled SiNPs causes chronic kidney injury that progresses despite stopping the SiNP administration. These findings are consistent with the hypothesis that human exposure to amorphous silica nanoparticles found in burned sugarcane fields could have a participatory role in chronic kidney disease of unknown etiology.

Chronic kidney disease of unknown etiology in India: a comparative study with Mesoamerican and Sri Lankan nephropathy

Chronic kidney disease of unknown etiology [CKDu] is a condition characterized by decline in kidney function and is not associated with diabetic nephropathy or hypertensive nephropathy. In this review, we have done a detailed literature analysis on CKDu in India, and then had a comparison with that of Mesoamerica and Sri Lanka. In India, CKDu became the second most common type of CKD after diabetic nephropathy. Silica was seen in the groundwater of both India and Sri Lanka, whereas in Mesoamerica silica exposure through particulate matter was seen among CKDu communities. DDE is a common agrochemical seen in both India and Sri Lanka. The risk factors vary from region to region and it is important to categorize CKDu population based on the risk factors to avoid misinterpretation of the condition as non-CKDu category and to evade further complications. More studies have to be conducted to reveal the detailed pathophysiological mechanisms and its relation with irrational exploitation of environmental resources.

Chronic Kidney Disease of Unknown Etiology in India: What Do We Know and Where We Need to Go

Chronic kidney disease (CKD) not associated with known risk factors has been reported from parts of India and is presumed to be similar to CKD of unknown etiology (CKDu) that has been described from Central America. The reports from India have been fragmented without clear description of the disease phenotype or its determinants. This paper summarizes the current state of knowledge around CKDu in India based on a review of literature, multi-stakeholder consultation, and a survey of Indian nephrologists. We also contacted individual research groups to solicit data. Our findings suggest that that CKDu is reported from most regions in India; however, it is interpreted differently from the phenotype described from Central America and Sri Lanka. The differences include lack of a clear demographic or occupation group, older age of affected participants, and presence of mild hypertension and low-grade proteinuria. Well-designed prospective field studies with appropriate diagnostic workup are needed to establish the disease burden and identify etiologies, along with socioeconomic and health consequences, the intersection with the environment, and the public health response. Community-based research should phenotype the entire CKD population rather than be restricted to cases with presumed CKDu based on predefined criteria. Guidelines are needed for clinical evaluation, referral, management, and harmonization of clinical documentation and health records. More data are needed to support the existence of a unique CKDu phenotype in India.

Burden of chronic kidney disease in the general population and high-risk groups in South Asia: A systematic review and meta-analysis

BACKGROUND

Chronic kidney disease (CKD) is an emerging public health issue globally. The prevalence estimates on CKD in South Asia are however limited. This study aimed to examine the prevalence of CKD among the general and high-risk population in South Asia.

METHODS

We conducted a systematic review and meta-analysis of population-level prevalence studies in South Asia (Afghanistan, Bangladesh, Bhutan, Maldives, Nepal, India, Pakistan, and Sri Lanka). Three databases namely PubMed, Scopus and Web of Science were systematically searched for published reports of kidney disease in South Asia up to 28 October 2020. A random-effect model for computing the pooled prevalence was used.

RESULTS

Of the 8749 identified studies, a total of 24 studies were included in the review. The pooled prevalence of CKD among the general population was 14% (95% CI 11-18%), and 15% (95% CI 11-20%) among adult males and 13% (95% CI 10-17%) in adult females. The prevalence of CKD was 27% (95% CI 20-35%) in adults with hypertension, 31% (95% CI 22-41%) in adults with diabetes and 14% (95% CI 10-19%) in adults who were overweight/obese. We found substantial heterogeneity across the included studies in the pooled estimates for CKD prevalence in both general and high-risk populations. The prevalence of CKD of unknown origin in the endemic population was 8% (95% CI 3-16%).

CONCLUSION

Our study reaffirms the previous reports that CKD represents a serious public health challenge in South Asia, with the disease prevalent among 1 in 7 adults in South Asian countries.

Environment and chronic kidney disease in farmers

The prevalence of chronic kidney disease (CKD) has been on the rise worldwide. Epidemiological studies performed primarily in Central America and South Asia have reported high prevalence of CKD among young and middle-aged men working in agricultural communities. The clinical features do not appear linked to any classical CKD risk factors, such as hypertension, diabetes, or chronic nephritis. The disease develops and progresses as interstitial nephritis, without showing noticeable symptoms or high levels of proteinuria. Pathologically, the disease essentially represents chronic interstitial nephritis and is termed chronic interstitial nephritis in agricultural communities (CINAC). The potential causes of CINAC include: (1) heat stress-related factors associated with increased ambient temperatures resulting from global warming; and (2) factors connected with exposure to agrochemicals and/or pesticides. Global warming and environmental pollution will undoubtedly pose a significant health risk to farmers, and heat stress during farm work could easily result in the development and progression of CKD. Japanese agricultural regions evidently will not be spared from global environmental changes. For future epidemiological studies, researchers should establish a more comprehensive analytical method that can incorporate additional risk-factor variables, such as occupational history (including agricultural work) and ambient temperature.

Environmental risk factors for reduced kidney function due to undetermined cause in India: an environmental epidemiologic analysis

BACKGROUND

An epidemic of chronic kidney disease is occurring in rural communities in low-income and middle-income countries that do not share common kidney disease risk factors such as diabetes and hypertension. This chronic kidney disease of unknown etiology occurs primarily in agricultural communities in Central America and South Asia. Consequently, environmental risk factors including heat stress, heavy metals exposure, and low altitude have been hypothesized as risk factors. We conducted an environmental epidemiological analysis investigating these exposures in India which reports the disease.

METHODS

We used a random sample population in rural and urban sites in Northern and Southern India in 2010, 2011, and 2014 (n = 11,119). We investigated associations of the heat index, altitude, and vicinity to cropland with estimated glomerular filtration rate (eGFR) using satellite-derived data assigned to residential coordinates. We modeled these exposures with eGFR using logistic regression to estimate the risk of low eGFR, and linear mixed models (LMMs) to analyze site-specific eGFR-environment associations.

RESULTS

Being over 55 years of age, male, and living in proximity to cropland was associated with increased risk of low eGFR [odds ratio (OR) (95% confidence interval (CI) = 2.24 (1.43, 3.56), 2.32 (1.39, 3.88), and 1.47 (1.16, 2.36)], respectively. In LMMs, vicinity to cropland was associated with low eGFR [-0.80 (-0.44, -0.14)]. No associations were observed with temperature or altitude.

CONCLUSIONS

Older age, being male, and living in proximity to cropland were negatively associated with eGFR. These analyses are important in identifying subcommunities at higher risk and can help direct future environmental investigations.