Introduction:
Chronic Kidney Disease of unknown etiology (CKDu) has emerged as a significant public health issue. Although several potential risk factors have been proposed, including heavy metal contamination and fluoride in drinking water, robust epidemiological evidence connecting these factors to CKDu remains sparse. This study aims to assess and compare the levels of heavy metals and fluoride in patients with CKDu versus those with CKD of known etiology in central India.
Methods:
This comparative study was conducted from August 2022 to July 2023 in a tertiary care hospital in Central India. A total of 100 patients, 50 with CKDu and 50 with CKD of known etiology, between 18 to 60 years of age were included. Demographic and clinical parameters were recorded as per the predesigned Case Record proforma. Serum and urine samples were collected and analyzed for levels of Iron (Fe), Lead (Pb), Copper (Cu), Manganese (Mn), Nickel (Ni), Cadmium (Cd), and Chromium (Cr) using Atomic Absorption Spectrophotometry. Serum and urine fluoride were measured using ion-selective electrode method. The case definition of CKDu was based on criteria proposed by the Indian Society of Nephrology which includes eGFR<60 ml/min/sq. m and Urine Albumin:Creatinine ratio >30 mg/g for more than 3 months with Urine protein creatinine ratio(PCR) less than 2g/g; No history of glomerulonephritis, pyelonephritis, renal calculi, polycystic kidneys or obstruction on renal ultrasound; not on treatment for diabetes and HbA1c less than 6.5% and Blood pressure less than 140/90 if CKD stage 1 and 2; and less than 160/100 if CKD stage 3,4, and 5 and on a single drug for blood pressure control. Statistical analysis was done using SPSS version 27.
Results:
Majority of the participants were male (74%) and over the age of 50 years (mean age= 50.28+7.46 years). Majority of the participants of the CKDu group hailed from Mahasamund district of Chhattisgarh and Balangir distict of Odhisa. There were no significant differences in serum or urine levels of heavy metals (Fe, Pb, Mn, Cu, Ni, Cd and Cr) between CKDu and CKD of known etiology groups. However, CKDu patients exhibited significantly higher serum fluoride levels compared to the control group (0.22 mg/L vs. 0.09 mg/L, p < 0.001). Urine fluoride levels did not differ significantly between the two groups. Table 1 demonstrates the median serum and urine heavy metal and fluoride levels of the study population.
Conclusions:
This study is one of the first to analyze heavy metals and fluoride levels in CKDu patients in Central India and suggests that elevated serum fluoride could be associated with CKDu. While no significant differences were found for other heavy metals, the higher serum fluoride levels in CKDu patients may point to fluoride exposure as a potential contributing factor. The study supports the need for further research into environmental toxins and their role in CKDu and highlights the importance of monitoring fluoride levels in affected regions.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.