Comparison of different methods of estimation of glomerular filtration rate

Abstract

Background. Glomerular filtration rate (GFR) is a measure of how much blood is filtered by the kidneys each minute accordingly is considered as the best overall indicator for how well an individual's kidneys are functioning at a given moment.GFR cannot be measured directly in people. Objective of the study. To bring out the difference between estimation of GFR via commonly used different methods and compare them using clearance measures or serum levels of filtration indicators. Material and Methods. Study design - descriptive. WHO information sources, scientific papers from the PubMed database on different methods of estimation of GFR were studied using the selected keywords and the following criteria 1)English language 2)10 and more citations of the article 3)publications within 10 years Results. In both the immature and mature kidney, urinary clearance of inulin, remains the reference against which alternative clearance techniques and filtration indicators are assessed. GFR in newborns is assessed using creatinine, the most extensively used GFR measure in adults. Cystatin C is less affected by muscles than creatinine, but eGFR based on serum cystatin C (eGFRcys) is not more accurate than eGFRcr, because of various conditions affecting non-GFR determinants of serum cystatin-C. However, equations combining both these filtration markers(eGFRcr-cys) appear to be more precise than equations using either marker alone. Conclusion. The glomerulus filters inulin freely, and is neither released or reabsorbed in the tubules, and is nor synthetized or metabolized. As a result, urine inulin clearance is regarded as the golden standard for diagnosis.

Background. Glomerular filtration rate (GFR) is a measure of how much blood is filtered by the kidneys each minute accordingly is considered as the best overall indicator for how well an individual's kidneys are functioning at a given moment.GFR cannot be measured directly in people. Objective of the study. To bring out the difference between estimation of GFR via commonly used different methods and compare them using clearance measures or serum levels of filtration indicators. Material and Methods. Study design - descriptive. WHO information sources, scientific papers from the PubMed database on different methods of estimation of GFR were studied using the selected keywords and the following criteria 1)English language 2)10 and more citations of the article 3)publications within 10 years Results. In both the immature and mature kidney, urinary clearance of inulin, remains the reference against which alternative clearance techniques and filtration indicators are assessed. GFR in newborns is assessed using creatinine, the most extensively used GFR measure in adults. Cystatin C is less affected by muscles than creatinine, but eGFR based on serum cystatin C (eGFRcys) is not more accurate than eGFRcr, because of various conditions affecting non-GFR determinants of serum cystatin-C. However, equations combining both these filtration markers(eGFRcr-cys) appear to be more precise than equations using either marker alone. Conclusion. The glomerulus filters inulin freely, and is neither released or reabsorbed in the tubules, and is nor synthetized or metabolized. As a result, urine inulin clearance is regarded as the golden standard for diagnosis.