Abstract
The ability to assess renal function in diabetes patients rapidly and early is of major importance. This study was designed to determine whether cystatin C can replace serum creatinine as the screening marker for reduced glomerular filtration rate (GFR) in type 2 diabetes patients. The study was performed on 51 type 2 diabetic patients. GFR was estimated by the plasma clearance of 99mTc‐DTPA. The correlation between 99mTc‐DTPA clearance and levels of serum cystatin C, serum creatinine, and creatinine clearance was determined. Sensitivity and specificity for the diagnosis of renal impairment (defined as GFR<68 ml/min) were calculated by a receiver operating characteristic (ROC) curve for serum cystatin C, serum creatinine, and creatinine clearance. The correlation coefficients with 99mTc‐DTPA clearance were −0.744 for serum cystatin C, −0.658 for serum creatinine, and +0.625 for creatinine clearance (P<0.001). With a cutoff value of 68 mL/min, the area under the ROC curve (AUC) was 0.891 for cystatin C, 0.77 for creatinine, and 0.753 for creatinine clearance. The AUC was statistically different between serum cystatin C and creatinine clearance (P<0.05). The ROC plot indicates that cystatin C is superior to serum creatinine and creatinine clearance for detecting impaired GFR. Serum cystatin C appropriately reflects GFR in diabetes, and is more efficacious than serum creatinine and creatinine clearance in detecting reduced GFR in type 2 diabetes patients. J. Clin. Lab. Anal. 18:31–35, 2004. © 2004 Wiley‐Liss, Inc.
Keywords: cystatin C, type 2 diabetes, serum creatinine, glomerular filtration rate, creatinine clearance, receiver operating characteristic
REFERENCES
- 1. Mathiesen ER, Oxenboll B, Johansen K, Svendsen PA, Deckert T. Incipient nephropathy in type 1 (insulin dependent) diabetes. Diabetologia 1984;26:406–410. [DOI] [PubMed] [Google Scholar]
- 2. Shemesh O, Golbetz H, Kriss JP, Myers BD. Limitations of creatinine as a filtration marker in glomerulopathic patients. Kidney Int 1985;28:830–838. [DOI] [PubMed] [Google Scholar]
- 3. Randers E, Erlandsen EJ. Serum cystatin C as an endogenous marker of the renal function—a review. Clin Chem Lab Med 1999;37:389–395. [DOI] [PubMed] [Google Scholar]
- 4. Risch L, Huber AR. Assessing the diagnostic accuracy of cystatin C as a marker of impaired glomerular filtration rate. Am J Kidney Dis 2002;39:661–662. [DOI] [PubMed] [Google Scholar]
- 5. Mussap M, Vestra DM, Fioretto P, et al. Cystatin C is a more sensitive marker than creatinine for the estimation of GFR in type 2 diabetic patients. Kidney Int 2002;61:1453–1461. [DOI] [PubMed] [Google Scholar]
- 6. Oddoze C, Morange S, Portugal H, Berland Y, Dussol B. Cystatin C is not more sensitive than creatinine for detecting early renal impairment in patients with diabetes. Am J Kidney Dis 2001;38:310–316. [DOI] [PubMed] [Google Scholar]
- 7. World Health Organization . Definition, diagnosis and classification of diabetes mellitus and its complications. Part 1: Noncommunicable Disease Surveillance, 1999; p 1–49. [Google Scholar]
- 8. Risch L, Herklotz R, Blumberg A, Huber A. Effects of glucocorticoid immunosuppression on serum cystatin C concentration in renal transplant patients. Clin Chem 2001;47:2055–2059. [PubMed] [Google Scholar]
- 9. Bokenkamp A, Domanetzki M, Zinck R, Schumann G, Byrd D, Brodehl J. Cystatin C–a new marker of glomerular filtration rate in children independent of age and height. Pediatrics 1998;101;875–881. [DOI] [PubMed] [Google Scholar]
- 10. Finney H, Newman DJ, Price CP. Adult reference ranges for serum cystatin C, creatinine and predicted creatinine clearance. Ann Clin Biochem 2000;37:49–59. [DOI] [PubMed] [Google Scholar]
- 11. Newman DJ, Thakkar H, Edwards RG, et al. Serum cystatin C measured by automated immunoassay: a more sensitive marker of changes in GFR than serum creatinine. Kidney Int 1995;47:312–318. [DOI] [PubMed] [Google Scholar]
- 12. Harmoinen APT, Kouri TT, Wirta OR, et al. Evaluation of plasma cystatin C as a marker for glomerular filtration rate in patients with type 2 diabetes. Clin Nephrol 1999;52:363–370. [PubMed] [Google Scholar]
- 13. Grubb AO. Cystatin C—properties and use as diagnostic marker. Adv Clin Chem 2000;35:63–99. [DOI] [PMC free article] [PubMed] [Google Scholar]