Uraemia progression in chronic kidney disease stages 3-5 is not constant

Chronic kidney disease (CKD) is a progressive disease leading to loss of glomerular filtration rate (ΔGFR, measured in ml/min/1.73 m(2)/year). ΔGFR 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 ΔGFR is constant or accelerating.