Renal function – estimation of glomerular filtration rate

Abstract

Assessment and follow-up of renal dysfunction is important in the early detection and management of chronic kidney disease. The glomerular filtration rate (GFR) is the most accurate measurement of kidney disease and is reduced before the onset of clinical symptoms. Drawbacks to the measurement of GFR include the high cost and incompatibility with routine laboratory monitoring. Serum creatinine determination is a mainstay in the routine laboratory profile of renal function. The measurement of serum cystatin C has been proposed as a more sensitive marker for GFR. According to National Kidney Foundation-K/DOQ1 clinical guidelines for chronic kidney disease, serum markers should not be used alone to assess GFR. Based on prediction equations, clinical laboratories should report an estimate of GFR, in addition to reporting the serum value. In this article, information is presented on how best to estimate GFR using prediction equations for adults and for children. Using serum creatinine concentration with the Modification of Diet in Renal Disease (MDRD) study equation offers a suitable estimation of GFR in adults. The cystatin C prediction equation with the use of a prepubertal factor seems superior to creatinine-based prediction equations in children of <14 years.

New Predictive Equations Improve Monitoring of Kidney Function in Patients With Diabetes

“…Our work mainly shows that it is promising to evaluate CKD progression in diabetic subjects with various Cys-eGFR equations, in agreement with the point of view that specific prediction formulae could be used for particular patient groups (32). Disease-specific formulae have to be restricted to specific medical prescription owing to the frequent lack of clinical information concerning referred patient samples in laboratories (16). This study provides a kinetic basis for previous static work reporting that serum cystatin-C is valuable in detecting early or mild diabetic nephropathy (33) for screening early impairment of renal function at a time when active management is important.…”

“…The cystatinestimated GFR (Cys-eGFR) according to Arnal and colleagues (16,17) was used in 208 patients aged 1-80 years with various etiologies and with insulin determination of GFR as follows: Cys-eGFR (Arnal-Dade) ϭ 74.835/(CysC 1.333 ).…”

“…The four cystatin-based equations were recently proposed 1) in the general population by Rule et al (15) and Arnal and colleagues (16,17) and 2) in diabetic patients by Tan et al (18) and MacIsaac et al (19). To focus on biases according to GFR level, we performed a Bland-Altman procedure and repeated the comparison after categorizing the subjects in tertiles of GFR levels.…”

Low bone mineral density is associated with insulin resistance in bone marrow transplant subjects

“…Glomerular filtration rate was estimated by the Modification of Diet in Renal Disease abbreviated equation. 16 Insulin resistance and secretion were estimated through the Homeostatic Model Assessment for insulin resistance (HOMA-IR) and Homeostatic Model Assessment for b-cell function (HOMA-B), respectively. 17 Blood samples were collected between 13:00 and 14:00 hrs, after a fasting of at least 4 h. All samples were frozen at À70 1C and analyzed at the same time.…”

The usefulness of cystatin C and related formulae in pediatrics

“…Where serum endogenous markers are considered as suitable markers of GFR, the National Kidney Foundation guidelines recommend the use of serum marker based prediction equations for GFR estimation and rules against the use of serum markers alone in the assessment of renal function, as discussed in ref. (34) .…”