[Tables estimating glomerular filtration rate from plasma creatinine]

Chronic kidney disease (CKD) and its related complications have become an important health and social problem. Very expensive resources are required in end-stage renal disease, and both complications of CKD as well as the important associated cardiovascular risk demand for interventions long before renal substitution therapies are needed. Thus, early diagnosis of CKD is currently considered of paramount importance, and it is based essentially upon the estimation of the glomerular filtration rate by formulae such as the abbreviated equation of the MDRD study. Nevertheless, in spite of international published recommendations, an automatic calculation to estimate the glomerular filtration rate (GFR) from serum creatinine is not reported by most laboratories yet and the need for creatinine assay standardisation is far from being implemented. Thus, we have designed some tables to show the creatinine value corresponding to different GFR for ages between 20 and 90 y/o, at 5 years intervals and in both sexes with both the MDRD-4 and MDRD-IDMS equations (Modification of Diet in Renal Disease-Isotope Dilution Mass Spectrometry). Moreover, we have created a global table including an estimation of GFR from plasma creatinine, age and sex by the MDRD-IDMS formula, the recommended for those laboratories which measure serum creatinine with assays aligned to the reference method. These tables aim to increase the awareness of the different assays for serum creatinine and to facilitate the diagnosis of CKD converting serum creatinine into GFR. This action should allow not only the early detection but also the possibility to establish the appropriate medical actions recommended after CKD detection.