Assessment of the estimations of glomerular filtration rate in Chinese diabetic patients / 中华检验医学杂志

ABSTRACT

Objective To assess the applicability of the Modification of Diet in Renal Disease (MDRD)formula to kidney function impaired Chinese diabetic patients.Methods Glomerular filtration rates(GFRs)in 463 Chinese diabetic patients(219 female,244 male,aged 14 to 88)were estimated by measuring ~(99m)Tc-DTPA clearance and with equations based on serum creatinine(Scr)and cystatin C(Cys C)concentrations.GFRs derived from various equations were compared with the ~(99m)Tc-DTPA clearance GFRs and their relative accuracies were assessed with ROC analysis.All the Scr measurements were performed with both the Roche enzymatic assay and the Beckman LX20 kinetic alkaline picrate assay,and Cys C with immunonephelometric and immunoturbidimetric assays.Results The reciprocals of Cys C and Scr were linearly correlated with ~(99m)Tc-DTPA clearance GFRs(r=0.830 and 0.690,repectively).The correlation of GFR with Scr could be expressed by an adjusted MDRD equationGFR [ ml?(min?1.73 m~2)~(-1)]=175?(Scr)~(-1.154)?(age)~(-0.203)?0.742(female)?0.827,where 0.827 was a coefficient for Chinese.The adjusted equation showed a better accuracy than the MDRD equation(areas under the ROC curve 0.818 vs 0.644).The adjusted equation was also more accurate than equations obtained in previous Chinese studies.GFRs were also estimated by using Cys(in mg/L)with the following equationGFR [ ml?(min?1.73 m~2)~(-1)] = 63.24?(Cys C)~(-0.3378).The accuracy of the Cys equation was similar to the Scr equation,or better in patients aged 60 and above.The Roche enzymatic results which were traceable to the isotope dilution mass spectrometry(IDMS)methods were significantly lower than Beckman LX20 results,but the results were closely correlated with each other(Y = 0.94X-0.02).When non-traceable Scr results were used,the coefficient needed to be adjusted.Conclusions GFRs can be estimated with equations based on either Scr or Cys C.GFR estimation should use standardized Scr results and take into account ethnic effects.