A proposal for improving the KDIGO renal disease risk table

Abstract

Recent surveys have revealed that the prevalence of chronic kidney disease (CKD), particularly the hidden mild form (mildly elevated levels of serum creatinine or urinary albumin excretion), is surprisingly high in the general population. In recent years, the global epidemic of type-2 diabetes has led to an alarming increase in the number of patients with CKD. Most patients with CKD (over 50 million individuals worldwide) succumb to cardiovascular events, while each year over 1 million develop end-stage renal failure, which requires costly treatment and in many countries of the world, unaffordable renal replacement therapy by chronic dialysis or renal transplantation [1]. The diagnosis and management of CKD has been made easier in recent years by the Kidney Disease Outcomes Quality Initiative (K/DOQI) clinical practice guidelines of the US National Kidney Foundation. The K/DOQI guidelines advise that CKD can be defined and appropriately managed by a staging approach that relies on estimating the severity of kidney damage based on the degree of proteinuria and impaired kidney function, the latter assessed as a decrease in the glomerular filtration rate (GFR). CKD is defined as kidney damage for [3 months, with or without decreased GFR, manifested by either pathologic abnormalities or markers of kidney damage such as proteinuria 3.4. If there are no signs of kidney damage, a diagnosis of CKD cannot be made until the GFR is\60 mL/min/1.73 m [2]. Using this standard of measure, the National Kidney Foundation estimates that 20 million Americans have CKD, while an additional 20 million are at risk of the disease [3]. During this time, an increasing recognition has emerged about the definition and classification limitations, leading to a heated debate and calls for revisions, mainly in nephrology subspecialty journals. The leadership of KDIGO (Kidney Disease: Improving Global Outcomes), with the endorsement of K/DOQI, convened a Controversies Conference to provide a forum for an open discussion on this problem [4]. One important issue was whether or not the current classification (based on eGFR) should be modified to include additional factors associated with prognosis. The conference generated a table similar to the one used for the European Hypertension Guidelines [5]. It was drawn by a composite ranking of relative risks that enhances communication about prognosis in which colours indicate groups of patients at progressively higher risk for the major outcomes. This table (Fig. 1) would help clinicians, researchers and public health agencies to describe and prioritise efforts aimed at patients and populations at risk of renal disease. The main improvement in the table is to add the value of urinary albumin excretion categorised by N. R. Robles J. F. Macias J. Alvarez-Gregori Cardiovascular Risk Chair, University of Salamanca School of Medicine, Salamanca, Spain