Approximately 1 out of 3 children in Andhra Pradesh, 1 out of 5 in Telangana have impaired kidney function: Study

Researchers discovered that 29.6 percent of children and adolescents in Andhra and 19.8 percent in Telangana have impaired kidney function.

BySumit Jha

Published Jul 06, 2024 | 7:00 AM Updated Jul 07, 2024 | 10:08 AM

Andhra Kidney disease

A study found that approximately one in every three children and adolescents in Andhra Pradesh and one in every five in Telangana have impaired kidney function and attributed the cause to various social factors.

The researchers discovered that 29.6 percent of children and adolescents in Andhra Pradesh, the highest rate in the country, and 19.8 percent in Telangana, the second highest, have impaired kidney function.

This study by researchers from the All India Institute of Medical Sciences (AIIMS) Bathinda, the International Institute for Population Sciences, Mumbai, and The George Institute for Global Health India in Delhi.

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Renal impairment

Impaired kidney function, also known as renal impairment or kidney dysfunction, refers to a condition where the kidneys are not working as well as they should.

This can affect the body’s ability to filter waste products from the blood, regulate electrolytes, and manage fluid balance. Impaired kidney function can range from mild to severe and can lead to Chronic Kidney Disease (CKD) or Acute Kidney Injury (AKI).

The researchers noted that CKD is a significant public health problem.

The burden of CKD in children and adolescents in India is not well described.

The study used data from the recent Comprehensive National Nutrition Survey (CNNS) to estimate the prevalence of Impaired Kidney Function (IKF) and its determinants in children and adolescents between the ages of five and 19.

“The prevalence of IKF among children and adolescents in India is high compared to available global estimates. In the absence of repeated eGFR-based estimates, these nationally representative estimates are intriguing and call for further assessment of socio-demographic disparities, genetics, and risk behaviours to gain better clinical insights and public health preparedness,” said the researchers.

Estimated Glomerular Filtration Rate (eGFR) is a calculation used to assess kidney function. It estimates how well the kidneys are filtering waste from the blood, specifically measuring the rate at which blood is filtered through the glomeruli, the tiny filters in the kidneys. eGFR is an important indicator used to detect and monitor kidney disease.

Overall, 4.9 percent of children and adolescents in India have impaired kidney function.

The study

The CNNS 2016–18 adopted a multi-stage sampling design using a probability proportional to size sampling procedure after geographical stratification of urban and rural areas. Serum creatinine was tested once in 24,690 children and adolescents aged 5–19 years.

The eGFR was derived using the revised Schwartz equation. An eGFR value below 60 ml/min/1.73 m² is defined as IKF. Bivariate analysis was done to depict the weighted prevalence, and multivariable logistic regression was used to examine the predictors of IKF.

The mean eGFR in the study population was 113.3 ± 41.4 mL/min/1.73 m². The overall prevalence of IKF was 4.9 percent.

The prevalence in the five to nine, 10 to 14, and 15 to 19 age groups was 5.6 percent, 3.4 percent, and 5.2percent, respectively.

Regression analysis showed that age, rural residence, non-reserved social caste, less educated mothers, Islam religion, severe stunting or being overweight/obese in children, and residence in Southern India were predictors of IKF.

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First-of-its-kind study

“It is a secondary analysis of national survey data. Kidney disease was not the primary focus of the survey, which aimed to assess overall child health in the country. However, serum creatinine values were collected, allowing us to derive estimates of renal function,” Dr Madhur Verma, one of the authors, told South First.

He added while this provides an acceptable measure of renal function, diagnosing CKD required at least two readings taken three months apart.

“This survey only provided a single reading, similar to methods used in other countries, which serves to highlight potential issues,” Dr Verma said.

“For a definitive study, participants should provide serum creatinine values over time, with measurements taken at least three months apart to confirm consistently high levels indicative of kidney disease. Despite using a single reading, we observed a higher number of children with abnormal readings in Telangana and Andhra Pradesh,” he added.

“Since the primary objective wasn’t kidney disease, we didn’t collect other critical data needed to establish associations and causation. We’ve noted this limitation in our manuscript, acknowledging that we could only analyse existing variables. Previous studies have shown a high prevalence of CKD among adult men, and this data suggests the problem is significant among children as well,” noted Dr Verma.

“So we assume that this problem is geographically clustered,” he said.

“This paper is meant to generate hypotheses and cannot be confirmatory. The intention is to draw attention to the high rates of impaired kidney function in this region and emphasise the need for further research. Every scientific inquiry begins with generating a hypothesis,” he added.

The need to answer the ‘why’

Dr Verma, drawing an analogy to Newton’s discovery of gravity, said, “When Newton saw the apple falling, he hypothesised why it was falling. The apple fell downward and not upward, which needed study. Similarly, every inquiry starts with asking ‘why?'”

“Now this question starts with ‘why.’ If we are not providing this data, we won’t have estimates for the country. We could not find any previous studies showing such estimates from India. Now, at least we have this data, raising concerns and prompting people to ask questions. This is important. Not every paper answers every question, but if it answers one question — what is the prevalence? — then it serves its purpose,” he said,

He said that they are generating hypotheses and providing estimates to start further research on CKD in children.

This data, collected by the ministry and detailed in the CNNS, includes renal function based on serum creatinine values. “We have gone a step further to calculate the glomerular filtration rate (GFR) based on creatinine values, height, and weight of the child, using a more sophisticated method,” he said.

“You can also see that report, which shows a darker colour in this region, indicating more children with higher serum creatinine values. Future studies need to investigate the causes — genetic analysis, environmental factors, and water quality. CKD is related not only to the patient but also to the environment. Genetic history, diet, and hydration status can affect creatinine values. For example, non-vegetarian diets can increase creatinine levels, and dehydration can cause high serum creatinine,” he pointed out.

“To diagnose CKD, we need at least three months of consistent readings. However, the high prevalence we found suggests that it cannot be solely due to factors like diet or hydration. The problem appears to be geographically clustered, indicating the need for more research to identify the underlying causes.”

Another author, Vivekanand Jha, said on X that the high prevalence of impaired kidney function among Indian children and adolescents underscored the urgent need for targeted interventions and policies to address this growing public health issue.

“Time to prioritise pediatric kidney health in national health,” he said.

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Geographic clusters with a high CKD burden

The study further said this is consistent with previous general population studies showing a higher CKD prevalence in the southern states.

Geographic clusters with a high CKD burden have been reported mostly from low-income and lower-middle-income countries consisting of young males from agricultural communities who have kidney failure without hypertension or proteinuria and are categorised as CKD of uncertain aetiology.

“Such clusters have also been reported from India, most commonly from Andhra Pradesh, Tamil Nadu, Goa and Odisha. Environmental and genetic studies need to be done in those areas to gather more information for the predictability and progression of the condition,” said the study.

Further, the study said that causation could be attributed to previous studies which had described geographical disparities in the burden of poverty, poor sanitation, pollutants, water contamination, overcrowding, and known and unknown nephrotoxins (including heavy metals and plant toxins in indigenous remedies) that need further exploration through robust studies.

According to the study, apart from the urban-rural divide, many caste, religious and cultural barriers also exist.

“We observed that children from Islam and the ‘other’ religions depicted a higher prevalence than Hindu children, but this association was non-significant in regression analysis,” it said.

Such disparities, if any, should be further evaluated, the study noted.

(Edited by Muhammed Fazil)

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