Application of creatinine- and/or cystatin C-based glomerular filtration rate estimation equations in elderly Chinese

Abstract

BackgroundNo conventional creatinine- or cystatin C-based glomerular filtration rate (GFR) estimation equation performed consistently outstandingly in elderly Chinese in our previous studies. This research aimed to further evaluate the performance of some recently proposed estimation equations based on creatinine and cystatin C, alone or combined, in this specific population.Materials and methodsThe equations were validated in a population totaling 419 participants (median age 68 [range 60–94] years). The estimated GFR (eGFR) calculated separately by ten equations was compared with the reference GFR (rGFR) measured by the 99mTc-DTPA renal dynamic imaging method.ResultsMedian serum creatinine, cystatin C, and rGFR levels were 0.93 mg/L, 1.13 mg/L, and 74.20 mL/min/1.73 m2, respectively. The Chinese population-developed creatinine- and cystatin C-based (Cscr-cys) equation yielded the least median absolute difference (8.81 vs range 9.53–16.32, P<0.05, vs the Chronic Kidney Disease Epidemiology Collaboration serum creatinine equation), the highest proportion of eGFR within 15% and 30% of rGFR (P15 and P30, 55.13 and 85.44, P<0.05 and P<0.01, vs the Chronic Kidney Disease Epidemiology Collaboration serum creatinine equation), and the lowest root mean square error (14.87 vs range 15.30–22.45) in the whole cohort. A substantial agreement of diagnostic consistency between eGFR and rGFR (with a kappa 0.61–0.80) was also observed with the Cscr-cys equation. Moreover, measures of performance in the Cscr-cys equation were consistent across normal to mildly injured GFR strata and individuals aged ≤80 years. Among all the Cscr-cys equations, the elderly Chinese-developed creatinine-based (CEscr) equation performed best in this specific population. Nevertheless, none of the equations achieved ideal manifestation in the moderately to severely GFR-injured group or in individuals aged ≥80 years.ConclusionThe Cscr-cys equation appeared to be optimal in elderly Chinese among the investigated equations. If cystatin C is not available, the CEscr equation is an acceptable alternative. A multicenter study with abundant subjects to develop an apposite formula for elderly Chinese is assumed to be essential.

Utility of cystatin C and serum creatinine‐based glomerular filtration rate equations in predicting vancomycin clearance: A population pharmacokinetics analysis in elderly Chinese patients

“…The CKD‐EPI cys‐scr was defined as a reference equation. A kappa value 0.21–0.40 is considered mild agreement, 0.41–0.60 moderate agreement, 0.61–0.80 substantial agreement, and 0.81–1.00 near perfect agreement (Ye et al., 2014). The results are shown in Supplementary material Table S1.…”

“…Cystatin C is less influenced by muscle mass, sex, age, and diet than serum creatinine (Levey et al., 2015). However, cystatin C based equations may be biased for patients suffering from thyroid disease or diseases typically treated with steroids (Ye et al., 2014). Several studies have shown that the CKD‐EPI cys‐scr equation based on a combination of serum creatinine and cystatin C achieved an ideal accuracy in a Chinese elderly population (Liu et al., 2013; Ye et al., 2014).…”

Efficacy and Safety of Nicorandil in Preventing Contrast-Induced Nephropathy after Elective Percutaneous Coronary Intervention: A Pooled Analysis of 1229 Patients

“…Therefore, the sensitivity of this biomarker is poor in evaluating early renal impairment. Cystatin C, another biomarker that is only cleared in the kidney, which increases when renal function is slightly impaired, is relatively stable for the reason that it is impervious to age, gender, diet, medications, or inflammation [ 36 , 37 ]. However, the raw data relevant to the continuous variables were a barrier to assess the postoperative renal biomarkers by meta-analyses.…”

Establishing the presence or absence of chronic kidney disease: Uses and limitations of formulas estimating the glomerular filtration rate

“…A number of studies compared the accuracy of various eGFR formulas in various populations and clinical conditions[ 41 - 63 ]. The great majority of these studies concluded that formulas based on serum cystatin C alone or on combined cystatin-creatinine levels are superior to other formulas[ 41 - 47 , 49 , 50 , 52 - 54 , 56 - 58 , 60 - 63 ]. One study found greater accuracy with the use of the average creatinine-based and creatinine/cystatin-based eGFR formulas[ 51 ].…”