[Estimation of glomerular filtration rate by inulin clearance: comparison with creatinine clearance].
Inulin clearance (Cin) is widely believed to be the gold standard of the glomerular filtration rate (GFR). However, in Japan, Cin has not been officially recognized by the Ministry of Health, Labour and Welfare of Japan for clinical use. Creatinine clearance (Ccr) has been used to estimate the renal function of patients, but there have been many studies in which Ccr estimates were GFR falsely high because the metabolism and tubular excretion of creatinine widely varied according to the pathophysiological state of the patient. In the present study, we determined Cin and Ccr simultaneously in 116 adult patients with renal diseases and diabetic mellitus. The clearance study was performed by the modified Wesson's method. The inulin preparation was FFI-1010 (Fuji Yakuhin Co. Ltd.). Inulin in serum and urine was determined by the newly devised enzymatic assay (Toyobo Co. Ltd.), which is specific for inulin. The mean Cin was 35.0 +/- 14.4 ml/min/1.73 m2. The mean Ccr(the enzyme assay) was 63.6 +/- 24.1 ml/min/1.73 m2 and that of the kinetic Jaffe assay was 55.3 +/- 19.3 ml/min/1.73 m2. Mean Ccr/Cin was 1.93 +/- 0.73, 1.69 +/- 0.62, respectively. This ratio was significantly different(p < 0.05) in the degree of reduction of Cin, with values of 2.07 +/- 0.82 (Cin < 40 ml/min/1.73 m2) and 1.64 +/- 0.32(40 < Cin < 80 ml/min/1.73 m2), respectively. Only 8 patients were classified into the same degree of reduced renal function (the Guideline of Japanese Society of Nephrology). The findings of this study suggest that the GFR determined by Ccr could misjudge the renal function of patient and delay the administration of proper treatment of the patient. Introduction of Cin into the clinical field is necessary to avoid this delay.
Orita
Yoshimasa
Y
College of Nutrition Koshien University, Hyogo.
Gejyo
Fumitake
F
Sakatsume
Minoru
M
Shiigai
Tatsuo
T
Maeda
Yoshitaka
Y
Imai
Enyu
E
Fujii
Takashi
T
Endoh
Masayuki
M
Jinde
Kiichiro
K
Haneda
Masakazu
M
Sugimoto
Toshiro
T
Hishida
Akira
A
Takahashi
Satoru
S
Hosoya
Tatsuo
T
Yamamoto
Hiroyasu
H
Hora
Kazuhiko
K
Okada
Yoichi
Y
Hosaka
Shigetoshi
S
Oguchi
Tomomasa
T
Kanno
Yutaka
Y
Nishio
Yasuhide
Y
Yano
Shintaro
S
Aikawa
Kazuo
K
Yasui
Kiyoshi
K
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000652:urine; D002908:Chronic Disease; D003404:Creatinine / Q000652:urine; D003920:Diabetes Mellitus / Q000503:physiopathology; D005260:Female; D005919:Glomerular Filtration Rate; D005921:Glomerulonephritis / Q000175:diagnosis* / Q000503:physiopathology*; D006801:Humans; D007444:Inulin / Q000652:urine; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000175:diagnosis / Q000503:physiopathology
D015415:Biomarkers; D007444:Inulin; D003404:Creatinine