title: Applicability of a different estimation equation of glomerular filtration rate in Turkey.
abstract: We aimed to investigate the performance of various creatinine based glomerular filtration rate estimation equations that were widely used in clinical practice in Turkey and calculate a correction coefficient to obtain a better estimate using the isotope dilution mass spectrometry (IDMS)-traceable Modification of the Diet in Renal Disease (MDRD) formula. This cross-sectional study included adult (>18 years) outpatients and in patients with chronic kidney disease as well as healthy volunteers. Iohexol clearance was measured and the precisions and bias of the various estimation equations were calculated. A correction coefficient for the IDMS-traceable MDRD was also calculated. A total of 229 (113 male/116 female; mean age 53.9 ± 14.4 years) subjects were examined. A median iohexol clearance of 39.21 mL/min/1.73 m(2) (range: 6.01-168.47 mL/min/1.73 m(2)) was found. Bias and random error for the IDMS-traceable MDRD equation were 11.33 ± 8.97 mL/min/1.73 m(2) and 14.21 mL/min/1.73 m(2), respectively. MDRD formula seems to provide the best estimates. To obtain the best agreement with iohexol clearance, a correction factor of 0.804 must be introduced to IDMS-traceable MDRD equation for our study population.
authors.affiliation: Department of Internal Medicine, Division of Nephrology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey. mraltiparmak@yahoo.com
authors.forename: Mehmet Riza
authors.initials: MR
authors.lastname: Altiparmak
authors.forename: Nurhan
authors.initials: N
authors.lastname: Seyahi
authors.forename: Sinan
authors.initials: S
authors.lastname: Trabulus
authors.forename: Serkan Feyyaz
authors.initials: SF
authors.lastname: Yalin
authors.forename: Murat
authors.initials: M
authors.lastname: Bolayirli
authors.forename: Zeynep Gulnur
authors.initials: ZG
authors.lastname: Andican
authors.forename: Gultekin
authors.initials: G
authors.lastname: Suleymanlar
authors.forename: Kamil
authors.initials: K
authors.lastname: Serdengecti
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D003287:Contrast Media; D003404:Creatinine / Q000378:metabolism; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007472:Iohexol; D008297:Male; D008875:Middle Aged; D011865:Radioisotope Dilution Technique; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis* / Q000208:ethnology* / Q000378:metabolism; D014421:Turkey
chemical_list: D003287:Contrast Media; D007472:Iohexol; D003404:Creatinine