Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The plasma clearance of iohexol has recently been proposed as a new method for estimating GFR. The iohexol plasma clearance was compared with that of 51Cr-EDTA in 32 diabetic patients (12 IDDM, 20 NIDDM; age 23-70; diabetes duration 1-35 years) with normal to impaired renal function (serum creatinine: 0.8-6.4 mg/dL). Bolus i.v. injection of 51Cr-EDTA (1 muCi/kg) was followed by 5 mL slow i.v. injection of Omnipaque (Nycomed, Oslo, Norway). Samples for radioactivity and iohexol analysis were drawn at 0, 5, 10, 15, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300 min (+360 and 420 min if serum creatinine > 2.0; +1440 min if > 5.0 mg/dL). Iohexol was assayed in duplicate by HPLC throughout a Nova-Pak C18 column (Waters-Millipore, USA). Only the second peak obtained during elution of iohexol (about 4.5 min) was used for calculation. Dilution tests show highly linear regressions for concentrations between 3.25-650 micrograms/mL (r = 0.99). Imprecision of iohexol assay (the whole procedure from deproteinization to chromatography) was: intra-assay 1.4 +/- 1.5%, mlsd (95% CI: 1.0-1.8%); inter-assay 3.0 +/- 2.7% (1.4-4.6%). Iohexol plasma clearance ranged between 12.9 and 150.9 mL/min, while 51Cr-EDTA plasma clearance between 11.9 and 149.8 mL/min with excellent correlation (iohexol = 0.95 51Cr-EDTA + 2.49; r = O.995). Mean CV between the two methods was 1.7% (range 0-4.9%) with a significant negative correlation (r = 0.5 I, p = 0.007) with the GFR levels. Correlation between repeated measurements, performed in eight patients, was excellent (r = O.994, P = 0.0001). In diabetes, GFR measured by plasma clearance of iohexol shows an excellent agreement with plasma clearance of 51Cr-EDTA throughout a wide range of renal function. Iohexol provides an accurate alternative method for measuring GFR.
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PMID:Iohexol plasma clearance in determining glomerular filtration rate in diabetic patients. 957 53

OBJECTIVE-Assessment and follow-up of early renal dysfunction is important in diabetic nephropathy. Plasma creatinine is insensitive for a glomerular filtration rate (GFR) >50 ml/min and creatinine clearance is unwieldy and subject to collection inaccuracies. We aimed to assess the reproducibility, reliability, and accuracy of plasma cystatin C as a measure of GFR ranging from normal to moderate impairment due to type 1 diabetes in the presence of a normal plasma creatinine concentration. RESEARCH DESIGN AND METHODS-A sensitive immunoturbidimetric cystatin C assay was examined in 29 subjects with type 1 diabetes and 11 nondiabetic subjects. Duplicate measurements of the following were collected from each subject, 2 weeks apart: cystatin C, enzymatic plasma creatinine, 24-h creatinine clearance, GFR estimated from plasma creatinine by the Cockcroft-Gault equation, and iohexol clearance as a gold standard. RESULTS-Iohexol clearance ranged from 35 to 132 ml. min(-1). 1.73 m(-2). Plasma cystatin C compared well with the other clinically used tests. The reliability of cystatin C, as assessed by the discriminant ratio, was superior to creatinine clearance (3.4 vs. 1.5, P < 0.001) and the correlation of cystatin C with iohexol clearance (Rs -0.80) was similar to that of creatinine clearance (Rs -0.74) and superior to that of plasma creatinine and the Cockcroft-Gault estimate (Rs -0.54 and 0.66, respectively). Duplicate estimations were used to provide an unbiased equation to convert plasma cystatin C to GFR. CONCLUSIONS-Based on this study, cystatin C is a more reliable measure of GFR than creatinine clearance, is more highly correlated with iohexol clearance than plasma creatinine, and is worthy of further investigation as a clinical measure of GFR in type 1 diabetes.
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PMID:Clinical usefulness of cystatin C for the estimation of glomerular filtration rate in type 1 diabetes: reproducibility and accuracy compared with standard measures and iohexol clearance. 1240 47