Levels of GFR and protein-induced hyperfiltration in kidney donors: a single-center experience in India.
BACKGROUND
Some studies have shown that the normal range of glomerular filtration rate (GFR) was lower in an Indian population than in western populations. To verify these findings and determine whether it is physiological or an expression of subclinical disease, we measured GFR in a cohort of healthy Indian adults by using more stringent criteria to define "healthy" than used in previous studies.


METHODS
Cross-sectional study.


METHODS
109 healthy adults being evaluated for kidney donation with normal blood pressure, body mass index, urinalysis results, and protein excretion and symmetrical function on radionuclide renogram. Subjects followed a vegetarian diet with 1 g/kg of protein intake for 10 days before the study.


METHODS
Age, sex, relation to recipient (relative versus spouse), body surface area, body mass index, kidney size, serum creatinine level, and urinary protein-creatinine ratio. OUTCOME AND MEASUREMENTS: GFR measured as plasma clearance of technetium 99m diethyl-triamine-penta-acetic acid before and after amino-acid infusion (protein-induced hyperfiltration). Measurements were performed after a 12-hour fast.


RESULTS
Mean baseline GFR was 82.4 +/-12.7 mL/min/1.73 m(2) (95% confidence interval, 80.0 to 84.8). Mean stimulated GFR was 104.7 +/- 16.1 mL/min/1.73 m(2) (95% confidence interval, 101.6 to 107.8). Measured mean protein-induced hyperfiltration was 27.3% +/- 10.04% (range, 6.7% to 56%). In multivariable linear regression analysis, younger age, spousal donor, and larger average kidney size were associated with significantly greater baseline GFR, and only greater baseline GFR was associated significantly with stimulated GFR.


CONCLUSIONS
Dietary protein intake was not measured; a habitual low-protein diet cannot be excluded as a cause of low GFR.


CONCLUSIONS
Basal GFR is significantly lower than the normal value of 120 to 130 mL/min/1.73 m(2) in western populations. The conventional cutoff value of 60 mL/min/1.73 m(2) for defining chronic kidney disease might not be appropriate in India.
Barai
Sukanta
S
Department of Nuclear Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India. danzig@rediffmail.com
Gambhir
Sanjay
S
Prasad
Narayan
N
Sharma
Raj Kumar
RK
Ora
Manish
M
Kumar
Alok
A
Gupta
Amit
A
Parasar
Deep Shankar
DS
Suneetha
Batchu
B
D000328:Adult; D001830:Body Surface Area; D004044:Dietary Proteins / Q000008:administration & dosage; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D007194:India; D007668:Kidney / Q000502:physiology; D016030:Kidney Transplantation / Q000502:physiology*; D016014:Linear Models; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D044465:White People
D004044:Dietary Proteins