Diabetes Care, Vol 21, Issue 2 216-220, Copyright © 1998 by American Diabetes Association
Estimation of the glomerular filtration rate in NIDDM patients from plasma creatinine concentration after cimetidine administration
FA Kemperman, J Silberbusch, EH Slaats, AM Prins, JA Weber, RT Krediet and L Arisz
Department of Internal Medicine, University of Amsterdam, The Netherlands. m.a.zeeman@amc.uva.nl
OBJECTIVE: Glomerular filtration rate (GFR) can be estimated in patients
with renal disease from plasma creatinine concentration, age, sex, and body
weight according to the formula of Cockcroft and Gault. The hypothesis that
this method can be improved when tubular secretion of creatinine is
inhibited by cimetidine was studied in NIDDM patients. RESEARCH DESIGN AND
METHODS: In 30 outpatients with NIDDM and normo- (n = 10), micro- (n = 9),
or macroalbuminuria (n = 11), GFR was measured as the urinary clearance
during continuous infusion of 125I-labeled iothalamate. Plasma creatinine
concentration was analyzed with an enzymatic assay before and after 800 mg
t.i.d. oral cimetidine was given during a 24-h period. RESULTS: Plasma
creatinine rose in all patients after cimetidine administration and, as a
consequence, the clearance calculated with the Cockcroft-Gault formula
fell. The ratio of this formula and GFR decreased from 1.16 +/- 0.20 to
0.97 +/- 0.16 (means +/- SD). This ratio tended to be smaller in the normo-
(0.93) than in the micro- (0.98) and macroalbuminuric (1.00) groups. Also,
20 patients with a BMI < 30 kg/m2 had a smaller ratio than those with a
BMI > 30 kg/m2 (0.92 vs. 1.07; P < 0.05). Bland and Altman analysis
showed a difference of the Cockcroft-Gault formula and GFR of 12.0 +/- 17.4
ml.min-1 (1.73 m2)-1, which decreased to -3.8 +/- 14.8 ml.min-1.(1.73
m2)-1. The same analysis of 24-h creatinine clearance with urine collection
and GFR showed larger standard deviations. CONCLUSIONS: GFR can be
estimated in an acceptable way from plasma creatinine concentration after
cimetidine administration in outpatients with NIDDM. Despite a
nonsignificant underestimation in normoalbuminuric and overestimation in
overweighted patients, this method is superior to 24-h creatinine clearance
with outpatient urine collection.