Physiological setback for Indian kidneys
doi:10.1038/nindia.2008.195 Published online 1 May 2008
Healthy Indians have lower Glomerular Filtration Rate — the best measure of kidney function — than their western counterparts due to physiological differences, a new study has found.
The normal glomerular filtration rate (GFR which determines the stage of kidney disease) in healthy Indians was found to be lesser than Western populations in earlier studies. "But it was not clear whether this difference is a reflection of subclinical kidney disease, or is simply physiological," says one of the researchers Sukanta Barai. To investigate this, the research team measured GFR among healthy adult Indian men and women who were potential voluntary kidney donors for relatives or spouses with end-stage renal disease.
They used the rate of plasma clearance from the glomerular capillary walls of these individuals as an indicator of baseline GFR. This was found to be lower than the normal GFR reported in western populations (80.0–84.8|ml/min/1.73|m2 as against 120–130|ml/min/1.73|m2). However, the mean kidney size and protein-induced hyperfiltration, were equivalent to values derived from studies of whites.
The team concluded that low GFR in Indians as compared to westerners was perhaps physiological (probably as a result of a vegetarian diet), and suggested that the National Kidney Foundation GFR threshold to define chronic kidney disease (<60|ml/min/1.73|m2) might not be applicable in Indian populations. "A cut off value of 45 ml/min appears more appropriate for Indians," Barai adds.
- Barai, S. et al. Levels of GFR and protein-induced hyperfiltration in kidney donors: a single-center experience in India. Am. J. Kidney Dis. 51, 407-414 (2008)