Glomerular filtration rate measurement by "single-shot" injection of inulin.
In 14 ADPKD patients the total body clearance and the urinary clearance of inulin using the constant infusion method were compared with the "single-shot" technique. Triplicate measurements of both clearances by each infusion method were obtained in 12 out of 14 patients. A high correlation was found between the total body clearance and the urinary clearance for both the constant infusion method (r = 0.96) and the single injection technique (r = 0.96). The coefficient of variation for the total body clearance of inulin was significantly lower for the constant infusion method and the single injection technique (7.8% and 7.1%) than for the urinary clearance of inulin (11.3% vs. 9.7%, P < 0.05). A constant overestimation of the urinary clearance by the total body clearance was observed with both methods (constant infusion method 8.3 ml.min-1 x 1.73 m-2 and single injection technique 13.4 ml.min-1 x 1.73 m-2). No concentration-dependent clearance was present. Determination of plasma inulin, especially at low levels, showed substantial interference by glucose. We conclude that, taking into account a constant overestimate of urinary clearance by the total body clearance of inulin, the single injection total body clearance possesses the best reproducibility and shows a good agreement with the conventional urinary clearance, which can be calculated by: GFR = TBCLss-13.1 ml.min-1 x 1.73 m-2 (in the range of 28 to 124 ml.min-1 x 1.73 m-2).
Florijn
K W
KW
Department of Nephrology, University Hospital Leiden, The Netherlands.
Barendregt
J N
JN
Lentjes
E G
EG
van Dam
W
W
Prodjosudjadi
W
W
van Saase
J L
JL
van Es
L A
LA
Chang
P C
PC
D000328:Adult; D000368:Aged; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D007444:Inulin / Q000008:administration & dosage*; D007678:Kidney Glomerulus / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D016891:Polycystic Kidney, Autosomal Dominant / Q000378:metabolism*; D015203:Reproducibility of Results
D007444:Inulin