Uraemia Progression in Chronic Kidney Disease Stages 3-5 Is Not Constant

作者：Heaf James Goya^*; Mortensen Leif Spange

来源：Nephron Clinical Practice, 2011, 118(4): C367-C374.

DOI：10.1159/000323391

• Uraemia
• Glomerular filtration rate
• Creatinine clearance
• Hyperfiltration

Introduction: Chronic kidney disease (CKD) is a progressive disease leading to loss of glomerular filtration rate (Delta GFR, measured in ml/min/1.73 m(2)/year). Delta GFR is usually assumed to be constant, but the hyperfiltration theory suggests that it accelerates in severe uraemia. A retrospective analysis of estimated GFR (eGFR) calculated from the Modification of Diet in Renal Disease equation was performed to evaluate whether Delta GFR is constant or accelerating. Methods: 1,441 patients attending a nephrology clinic over a 21-year period, with an initial eGFR <60 ml/min/1.73 m(2) and an observation period >= 2 years, were included. eGFR was calculated from all creatinine measurements. 420 patients developed end-stage renal disease (ESRD). First-and second-order polynomial regression analysis of eGFR against time was performed for each patient individually. Patients had accelerating uraemia progression if the second-order term coefficient was negative. Results: The initial eGFR was 30.8 +/- 15.1 ml/min/1.73 m(2). The second-order coefficient was median -0.15 ml/min/1.73 m(2)/year(2) (interquartile range -0.92, +0.34). Significantly more patients had an accelerating loss (62%, p <0.001). Acceleration was mainly seen when eGFR was <30 ml/min. Delta GFR was mean 1.47 +/- 4.5 ml/min/1.73 m(2)/year (male 1.67, female 1.22). ESRD patients lost 5.4 +/- 5.4 ml/min/year/1.73 m(2) during the last year before ESRD. Accelerating loss was seen for all diagnoses except polycystic disease. Diagnoses with higher Delta GFR were polycystic renal disease (3.3 ml/min/1.73 m(2)/year), hypertensive nephropathy (2.1 ml/min/1.73 m(2)/year) and diabetic nephropathy (2.6 ml/min/1.73 m(2)/year). There was no evidence of improvement in overall uraemia progression during the period of observation. Conclusions: Uraemia progression in CKD stages 3-5 is not linear, but shows an accelerating trend. This suggests that hyperfiltration mechanisms play a role in CKD progression. ESRD cannot thus be predicted from previous Delta GFR alone.

• 出版日期2011