Measurement Error as Alternative Explanation for the Observation that CrCl/GFR Ratio is Higher at Lower GFR.

ABSTRACT:

Background and objectives

Overestimation of GFR by urinary creatinine clearance (CrCl) at lower levels of GFR has long been attributed to enhanced creatinine secretion. However, this does not take into consideration the contribution of errors in measured GFR (and CrCl) due to short-term biologic variability or test imprecision.

Design, setting, participants, & measurements

We analyzed cross-sectional data among 1342 participants from the Chronic Renal Insufficiency Cohort study with baseline measurement of GFR by iothalamate clearance (iGFR) and CrCl by 24-hour urine collection. We examined the CrCl/iGFR ratio classified by categories of iGFR and also by categories of CrCl.

Results

Overall, mean CrCl/iGFR ratio was 1.13. CrCl/iGFR ratio was higher at lower iGFR catego

SUBMITTER: Zhang X 

PROVIDER: S-EPMC5012489 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature