Abstract:
Abstract Chronic kidney disease of uncertain etiol ogy (CKDu) is a common health issue among farming
communities in the dry zone of Sri Lanka where
groundwater fluoride is known to be higher than
recommended levels. Excessive environmental inges tion of fluoride is widely considered as a possible
factor for the onset of CKDu. This study was carried
out to evaluate the serum and urine fluoride levels in
biopsy-proven, non-dialysis CKDu patients. Control
subjects were selected from the same area without any
deteriorated kidney functions. Serum and urine fluo ride levels were determined by ion-selective electrode
method. Higher content of serum and urine fluoride
levels were observed in patients with chronic renal
failures. In CKDu cases, the serum fluoride concen trations ranged between 0.47 and 9.58 mg/L (mean
1.39 ± 1.1 mg/L), while urine levels were varied
between 0.45 and 6.92 mg/L (mean 1.53 ± 0.8 mg/
L). In patients, urine fluoride levels showed a signif icant difference with the CKDu stage; however, no
difference was obtained between genders and age. In
endemic controls, serum and urine fluoride levels
ranged between 0.51 and 1.92 mg/L (mean = 1.07 ±
0.3 mg/L) and 0.36 and 3.80 mg/L (mean = 1.26 ±
0.6 mg/L), respectively. Significantly higher fluoride
in serum and urine was noted in CKDu patients
compared to endemic control groups. Higher fluoride
exposure via drinking water is possibly the reason for
higher fluoride in serum, while excessive urinary
excretion would be due to deterioration of the kidney,
suggesting a possible nephrotoxic role of environ mental fluoride exposure
