Measured and estimated glomerular filtration rate. Numerous methods of measurements (Part I)

Abstract

The loss of half the renal mass does not necessarily imply half the Glomerular Filtration Rate (GFR), meaning that there is not an exact correlation between renal mass reduction and renal function loss. GFR is a necessary index for diagnosis and to establish chronic renal disease stages, followup of renal failure patients, epidemiological studies, adjustment of nephrotoxic drugs or renal excretion drugs, among other uses. This update briefly analyzes the principal methods used in order to estimate glomerular filtration, some of its strengths and weaknesses. The use of estimated GFR in epidemiological studies has contributed to generate a wide scale of controversies that instead of contributing to scientific progress, have produced endless discussions because of misleading argumentations and deviations for these calculations. Equations applied for estimating GFR in population studies, should be reconsidered, given their imperfection and the difficulty for clinicians, who are not specialists on the subject, to interpret the results.

Keywords

• tasa de filtración glomerular
• función renal
• ecuaciones de estimación
• clearance