Published Oct 21, 2026 | 7:00 AM ⚊ Updated Oct 21, 2026 | 7:00 AM
Participants aged 60 and above faced 1.92 times the odds of renal impairment compared with younger participants.
Synopsis: A community-based study in Kerala’s Ettumanoor found impaired kidney function in up to 44.4 percent of 1,031 adults screened, depending on the estimation method. Of 377 participants identified using one equation, only seven knew their kidney disease status. Researchers call for integrating kidney screening into existing non-communicable disease programmes.
A community-based study in Keralam’s Ettumanoor municipality found that only seven of the 377 adults identified with impaired kidney function were aware of their kidney disease status. The remaining 370, or 98.2 percent, did not know they had the condition, based on the study’s assessment using the Modification of Diet in Renal Disease (MDRD) equation.
“Only 1.8 percent were aware of their disease status,” the researchers wrote in a study published ahead of print in the Indian Journal of Medical Research on 12 October.
The researchers screened 1,031 adults aged 30 and above between March 2024 and February 2025. Depending on the equation used to estimate kidney function, between 24.9 percent and 44.4 percent of participants had renal impairment.
The findings point to a substantial burden of potentially undetected kidney dysfunction. The authors called for community-based screening to identify impairment before it progresses.
“This is the first community-based study that tries to identify the prevalence of renal impairment in the general population of Kerala,” they wrote.
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Researchers from the department of community medicine at Government Medical College, Kottayam, conducted the study across 19 wards of Ettumanoor municipality, which has 35 wards and a population of 50,398. Accredited social health activist (ASHA) workers helped identify households and collect information from eligible residents.
“Field work was done by ASHA workers who were trained in the methodology of data collection using a pretested questionnaire,” the researchers wrote.
The team selected one eligible adult aged 30 or above from each household. Where a household held more than one, a lottery picked the participant. Pregnant women and women in the puerperal period stayed out.
The researchers recorded demographic details, lifestyle, medical history and symptoms that suggest kidney disease. Participants then attended health camps at nearby subcentres or Anganwadis.
Staff drew fasting blood to measure serum creatinine and blood sugar, and used urine samples to calculate the albumin-to-creatinine ratio. They also measured blood pressure and body dimensions.
After the tests, a clinician visited the health centre to advise participants with abnormal results and plan further evaluation or treatment.
The participants had a mean age of 56.9 years. Women numbered 794 of the 1,031, or about 77 percent.
The share of adults with renal impairment shifted with the equation. The researchers used three methods because no single equation is validated for the Indian population.
The MDRD equation flagged 377 participants, or 36.6 percent. The Cockcroft-Gault equation gave the highest figure, 44.4 percent. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation gave the lowest, 24.9 percent.
“The variation across equations reflects the differences in sensitivity of these formulae, and underscores the need for an India-validated equation for estimating glomerular filtration rate (GFR),” the researchers wrote.
Estimated glomerular filtration rate (eGFR) shows how well the kidneys filter waste from blood. The paper defines renal impairment as an eGFR below 60 mL/min/1.73 m² or kidney damage shown by albuminuria, meaning a urine albumin-to-creatinine ratio above 30 mg/g of creatinine.
The researchers used the MDRD equation for their main analysis. They said the lack of a validated equation for India complicated the estimation of kidney function.
The line between renal impairment and chronic kidney disease matters. A single abnormal result cannot show that kidney dysfunction has lasted three months.
The authors said cross-sectional studies cannot show how long impairment lasts because “only a single value of serum creatinine or urine albumin-creatinine ratio (ACR) is used”.
The estimates exceed those from earlier Indian studies. “The prevalence of renal impairment in the study was significantly higher in comparison to Indian studies on impaired kidney function (3.2-22.6 percent),” the researchers wrote. The top of that range came from a study of a tribal population in Kerala.
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The regression analysis produced five associations that reached statistical significance: age of 60 and above, unmarried, widowed or divorced status, a history of hypertension, abdominal obesity and a raised urine albumin-to-creatinine ratio.
Participants aged 60 and above faced 1.92 times the odds of renal impairment compared with younger participants. Those who were unmarried, widowed or divorced faced 4.18 times the odds.
The researchers suggested that healthcare-seeking behaviour could partly explain the marital status link. “In the Indian scenario, mostly the spouse takes the partner for health checkups, thereby leading to the early detection of comorbidities,” they wrote.
They added that people without spouses may lack that prompt. “This healthcare-seeking behaviour might be lacking to an extent in unmarried/widowers/divorcees, leading to an increased incidence of renal impairment among them,” they wrote.
The study did not test healthcare-seeking behaviour, so the explanation remains a hypothesis, not an established cause.
A doctor’s past diagnosis of hypertension carried 2.97 times the odds. A urine albumin-to-creatinine ratio above 30 mg/g carried 2.98 times the odds.
Abdominal obesity showed the strongest link, with 8.18 times the odds. The researchers defined it as a waist circumference above 90 cm in men and 80 cm in women.
“The association of abdominal obesity in males and renal impairment concurs with the fact that obesity might independently contribute to glomerulopathy,” the authors wrote.
The intervals span 2.76 to 24.21 for abdominal obesity and 1.29 to 13.51 for marital status. The sample cannot fix the size of either association.
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Blood pressure readings showed hypertension in 609 participants, or 59.1 percent. Of the whole sample, 177 people, or 17.1 percent, did not know they had it.
The authors linked unawareness of hypertension to later kidney impairment. “Being unaware of hypertensive status can later lead to the development of renal impairment, as shown by our study,” they wrote.
The study measured participants once, so it cannot show whether hypertension came before kidney dysfunction in any individual.
Diabetes also featured. Based on HbA1c measurements, 418 participants, or 40.5 percent, met the study’s criteria. A history of diabetes did not emerge as an independent factor in the final regression analysis.
The researchers said kidney impairment needs more attention within India’s screening for non-communicable diseases, which already covers diabetes and hypertension.
“Despite the increasing focus on the screening of non-communicable diseases (NCD) by the Government of India, which identified covert diabetics and hypertensives, such screening processes are sparse in identifying the burden of renal impairment in the community,” they wrote.
They tied that gap to late diagnosis. “The lack of community-based screening programmes for renal impairment in India has led to patients being detected at an advanced stage, thereby burdening the healthcare ecosystem,” the paper said.
Symptoms seldom raise the alarm. “Early stages of renal impairment are often asymptomatic, allowing disease progression until a stage of irreversible kidney damage,” the authors wrote.
The paper lists dialysis, heart disease, bone loss and higher mortality as the outcomes, with financial strain on families.
It cites more than 100,000 new patients entering renal replacement programmes in India each year. For every patient with end-stage renal disease, it says, more than 200 have stage 3 or 4 impairment and almost 5,000 have stage 1 or 2.
The researchers recommended adding kidney screening to existing non-communicable disease programmes.
“The high burden of renal impairment, which was largely unidentified calls for the integration of screening for renal impairment into existing non-communicable disease programmes,” they wrote.
They named who should come first. “A stratified screening approach targeting those with hypertension, diabetes, advanced age, abdominal obesity, and unmarried or widowed status would be most cost-effective,” the authors said.
On prevention, they pointed to abdominal obesity and early detection of hypertension. “Lifestyle modification to reduce abdominal obesity, along with early detection and treatment of hypertension, can reduce the prevalence of renal impairment,” they wrote.
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The study covered one municipality, which limits how far the findings extend to Kerala or other parts of India. It relied on one measurement of serum creatinine and urine albumin-to-creatinine ratio, so it cannot show whether abnormalities persisted.
The team did not record diet or image the abdomen for kidney stones.
The authors raised diet as a question for later work. “The high rates of renal impairment in Kerala might be attributed to the Kerala lifestyle and diet, which includes red meat as a main dish,” they wrote.
They also flagged tapioca. “It is unknown whether the habit of increased intake of tapioca as a staple diet in the study population has led to renal impairment,” the researchers wrote.
Because the study did not document diet, it cannot show whether either food contributed to the findings.
The authors called for research to find the right kidney-function equation for India and to examine diet.
For now, the study offers a community-level estimate of impaired kidney function in one Kerala municipality, not an estimate of chronic kidney disease across the state. Its central finding is the gap between abnormal kidney function and awareness among those affected.
“Early renal impairment can be detected only with the efforts of a community-based screening programme,” the researchers wrote.
(Edited by Dese Gowda)
