Measuring GFR: A Systematic Review Soveri, Inga, MD, PhD; Berg, Ulla B., MD, PhD; Björk, Jonas, PhD ...
American journal of kidney diseases,
2014, Letnik:
64, Številka:
3
Journal Article
Recenzirano
Background No comprehensive systematic review of the accuracy of glomerular filtration rate (GFR) measurement methods using renal inulin clearance as reference has been published. Study Design ...Systematic review with meta-analysis of cross-sectional diagnostic studies. Setting & Population Published original studies and systematic reviews in any population. Selection Criteria for Studies Index and reference measurements conducted within 48 hours; at least 15 participants studied; GFR markers measured in plasma or urine; plasma clearance calculation algorithm verified in another study; tubular secretion of creatinine had not been blocked by medicines. Index Tests Endogenous creatinine clearance; renal or plasma clearance of chromium 51−labeled ethylenediaminetetraacetic acid (51 Cr-EDTA), diethylenetriaminepentaacetic acid (DTPA), iohexol, and iothalamate; and plasma clearance of inulin. Reference Test Renal inulin clearance measured under continuous inulin infusion and urine collection. Results Mean bias < 10%, median bias < 5%, the proportion of errors in the index measurements that did not exceed 30% (P30 ) ≥ 80%, and P10 ≥ 50% were set as requirements for sufficient accuracy. Based on the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach, the quality of evidence across studies was rated for each index method. Renal clearance of iothalamate measured GFR with sufficient accuracy (strong evidence). Renal and plasma clearance of51 Cr-EDTA and plasma clearance of iohexol were sufficiently accurate to measure GFR (moderately strong evidence). Renal clearance of DTPA, renal clearance of iohexol, and plasma clearance of inulin had sufficient accuracy (limited evidence). Endogenous creatinine clearance was an inaccurate method (strong evidence), as was plasma clearance of DTPA (limited evidence). The evidence to determine the accuracy of plasma iothalamate clearance was insufficient. With the exception of plasma clearance of inulin, only renal clearance methods had P30 > 90%. Limitations The included studies were few and most were old and small, which may limit generalizability. Requirements for sufficient accuracy may depend on clinical setting. Conclusions At least moderately strong evidence suggests that renal clearance of51 Cr-EDTA or iothalamate and plasma clearance of51 Cr-EDTA or iohexol are sufficiently accurate methods to measure GFR.
Background Very few studies have been published that compare plasma clearance of iohexol (Cio) with renal clearance of inulin (Cin). Study Design Diagnostic test study. Setting & Participants 60 ...children aged 11.6 ± 4.5 years with different kidney disorders were investigated. Index Test Plasma Cio calculated from the slope and a single point. Reference Test Renal Cin with continuous infusion during water diuresis. Results were compared with the correlation coefficients, bias and precision, accuracy percentage, root mean square error, and intraclass correlation. Other Measurements Measured creatinine clearance and estimated glomerular filtration rate based on serum creatinine level and height. Results Mean Cin was 70.7 ± 41.3 (SD) mL/min/1.73 m2 . Mean differences between Cio and Cin were 2.65 and 2.00 mL/min/1.73 m2 for the slope and single-point methods, respectively. Precision was ±16 mL/min/1.73 m2 and intraclass correlation was 0.92 in both methods. Proportions of Cio within 30% of Cin were 83.3% and 86.7% for the slope and single-point methods, respectively. Limitations A limited number of patients; no adults were studied. Conclusions Plasma Cio shows good agreement with renal Cin.
Objectives To examine the impact of hypothyroidism on renal function in children and the effect of thyroid hormone therapy on the long-term outcome. Study design The glomerular filtration rate (GFR) ...and effective renal plasma flow (ERPF) were studied in 31 patients with symptomatic acquired hypothyroidism (age, 11 ± 3.3 years) and in 50 healthy children (age, 10.5 ± 4.5 years). Children with hypothyroidism were examined before starting thyroxine therapy and 1 week and 1, 3, and 6 months after starting thyroxine therapy. 13 patients were reinvestigated at 6, 12, 18, 36, and 60 months after initiating thyroxine therapy. Results GFR and ERPF were <–2 SD of control levels in 58% and 45%, respectively, of children investigated before or within 1 week after starting thyroxine therapy. 31% and 6% of the children studied 1 to 6 months after thyroxine therapy had a GFR and ERPF <–2 SD. Moreover, when GFR and ERPF values were analyzed as percent of control mean, both measurements were reduced to an equal extent. At the last investigation, 1 to 5 years after start of treatment, the GFR was still significantly lower in children with hypothyroidism than that in control subjects. Conclusion Acquired hypothyroidism during childhood may have a long-term impact on renal function.
