Serial Measurements of Cystatin C are More Accurate than Creatinine-based Methods in Detecting Declining Renal Function in Type 1 Diabetes
- Erosha Premaratne, MBBS, FRACP1,
- Richard MacIsaac, PhD, MBBS, FRACP1,
- Sue Finch, PhD2,
- Sianna Panagiotopoulos, PhD1,
- Elif Ekinci, MBBS1 and
- George Jerums, MBBS,FRACP,MD1
- 1Endocrine Centre/Austin Health, Medicine/University of Melbourne, Melbourne, Australia
- 2Statistical Consulting Centre, University of Melbourne, Australia
Abstract
Objective Cystatin C and creatinine-based methods were compared with 99mTc-DTPA plasma clearance (isotopic Glomerular Filtration Rate or iGFR) for detecting declining renal function.
Research Design and Methods: GFR was monitored over a mean of 10.1 years in 85 subjects with type 1 diabetes (average of 5.6 measurements per individual). Baseline mean iGFR of the cohort was 106.1+2.6ml/min/1.73m2. The rates of decline in GFR (ΔGFR) were derived using linear regression.
Results In the 19/85 subjects with declining renal function (i.e. ΔiGFR>3.3ml/min/1.73m2 per year), ΔGFR (ml/min/1.73m2 per year) was: 6.5 by iGFR and 4.2 by 104/creatinine, 3.6 by Cockcroft-Gault formula, 3.4 by MDRD-6 -equation and 3.5 by MDRD-4 variable-equation (p<0.01 versus iGFR). In comparison, ΔGFR was 6.1 using the formula Cys-GFR=(86.7/cystatin C concentration)−4.2 (ns).
Conclusions Cystatin C was more accurate in detecting decline in renal function than creatinine-based methods in this population of subjects with Type 1 and a normal mean baseline GFR.
Footnotes
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- Received August 11, 2007.
- Accepted January 28, 2008.
- Copyright © American Diabetes Association
