Diagnostic Efficiency of Cystatin C and Serum Creatinine as Markers of Reduced Glomerular Filtration Rate in the Elderly

Abstract

This is a secondary analysis of data from a cross-sectional study to evaluate the diagnostic efficiency of cystatin C as a marker of the glomerular filtration rate in the elderly. Thirty patients (15 male, 15 female, mean age 75.4 +/- 7.1 years) attending a geriatric ward were enrolled. Exclusion criteria were previously diagnosed renal disease, dementia and heart failure (NYHA III or IV). Cystatin C in serum was determined by a particle-enhanced turbidimetric assay. Inulin clearance was assessed using a single-shot method. Also, Cockcroft-Gault formula was calculated. Twelve patients had a reduced glomerular filtration rate (<70 ml/min/ 1.73 m2). The mean values were 88.4 micromol/l (+/- 27.7) for serum creatinine, 1.57 mg/l (+/- 0.34) for cystatin C and 88.7 ml/min/1.73 m2 (+/- 34.6) for inulin clearance. Maximum efficiency was 0.73 for serum creatinine (cut-off limit 82 micromol/l), 0.67 for cystatin C (cut-off limit 1.63 mg/l) and 0.8 for Cockcroft and Gault estimation (cut-off limit 54 ml/min/1.73 m2). A receiver operating characteristics (ROC) analysis did not show any differences between the various methods. Therefore, cystatin C in serum may not improve the diagnostic efficiency in detecting a reduced glomerular filtration rate in the elderly. Furthermore, normal ranges for serum creatinine in the elderly might need to be adjusted.

Cystatin C: current position and future prospects

“…A simple comparison of correlations is not, however, statistically sufficient to confirm that CysC is superior to creatinine. CysC could be a more sensitive marker than creatinine to investigate for moderate reductions in GFR in the elderly (69-92 years old) (185,186), although the results reported are inconclusive (98,99).…”

Contrast Nephropathy: A Paradigm for Cardiorenal Interactions in Clinical Practice

“…The serum concentrations of cystatin C identify a condition of preclinical renal damage earlier than other laboratory parameters, and are also a possible risk marker for heart failure and other cardiovascular events in elderly patients. On the contrary, is not yet clear the real influence of other factors (cigarette smoking, thyroid disease, high levels of C-reactive protein, corticosteroid therapy) on these measurements (Burkhardt et al, 2002).…”

Exploration de la fonction glomérulaire rénale : estimation du débit de filtration glomérulaire

“…La cystatine C pourrait aussi être un marqueur plus sensible que la cré atinine pour dé pister les alté rations modé ré es du DFG chez le sujet âgé (69 à 92 ans) [158,159], même si des ré sultats non ou peu concluants ont aussi é té rapporté s [71,73,160]. Plus ré cemment, la BIS qui s'est inté ressé e (avec une mé thodologie trè s robuste) à l'estimation du DFG spé cifiquement chez la personne âgé e a rapporté une meilleure performance des é quations inté grant la cystatine C par rapport à celles inté grant uniquement la cré atininé mie [16].…”