Variability in CKD stage in outpatients followed in two large renal clinics: implications for CKD trials and the status of current knowledge of patterns of CKD to ESRD progression: response to Dr. Onuigbo

The CKD enigma with misleading statistics and myths about CKD, and conflicting ESRD and death rates in the literature: results of a 2008 U.S. population-based cross-sectional CKD outcomes analysis

The just released (August 2012) U.S. Preventive Services Task Force (USPSTF) report on chronic kidney disease (CKD) screening concluded that we know surprisingly little about whether screening adults with no signs or symptoms of CKD will improve health outcomes and that clinicians and patients deserve better information on CKD. The implications of the recently introduced CKD staging paradigm versus long-term renal outcomes remain uncertain. Furthermore, the natural history of CKD remains unclear. We completed a comparison of US population-wide CKD to projected annual incidence of end stage renal disease (ESRD) for 2008 based on current evidence in the literature . Projections for new ESRD resulted in an estimated 840,000 new ESRD cases in 2008, whereas the actual reported new ESRD incidence in 2008, according to the 2010 USRDS Annual Data Report, was in fact only 112,476, a gross overestimation by about 650%. We conclude that we as nephrologists in particular, and physicians in general, still do not understand the true natural history of CKD. We further discussed the limitations of current National Kidney Foundation Disease Outcomes Quality Initiative (NKF KDOQI) CKD staging paradigms. Moreover, we have raised questions regarding the CKD patients who need to be seen by nephrologists, and have further highlighted the limitations and intricacies of the individual patient prognostication among CKD populations when followed overtime, and the implications of these in relation to future planning of CKD care in general. Finally, the clear heterogeneity of the so-called CKD patient is brought into prominence as we review the very misleading concept of classifying and prognosticating all CKD patients as one homogenous patient population.

Renoprotection and the Bardoxolone Methyl Story - Is This the Right Way Forward? A Novel View of Renoprotection in CKD Trials: A New Classification Scheme for Renoprotective Agents

In the June 2011 issue of the New England Journal of Medicine, the BEAM (Bardoxolone Methyl Treatment: Renal Function in CKD/Type 2 Diabetes) trial investigators rekindled new interest and also some controversy regarding the concept of renoprotection and the role of renoprotective agents, when they reported significant increases in the mean estimated glomerular filtration rate (eGFR) in diabetic chronic kidney disease (CKD) patients with an eGFR of 20-45 ml/min/1.73 m(2) of body surface area at enrollment who received the trial drug bardoxolone methyl versus placebo. Unfortunately, subsequent phase IIIb trials failed to show that the drug is a safe alternative renoprotective agent. Current renoprotection paradigms depend wholly and entirely on angiotensin blockade; however, these agents [angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs)] have proved to be imperfect renoprotective agents. In this review, we examine the mechanistic limitations of the various previous randomized controlled trials on CKD renoprotection, including the paucity of veritable, elaborate and systematic assessment methods for the documentation and reporting of individual patient-level, drug-related adverse events. We review the evidence base for the presence of putative, multiple independent and unrelated pathogenetic mechanisms that drive (diabetic and non-diabetic) CKD progression. Furthermore, we examine the validity, or lack thereof, of the hyped notion that the blockade of a single molecule (angiotensin II), which can only antagonize the angiotensin cascade, would veritably successfully, consistently and unfailingly deliver adequate and qualitative renoprotection results in (diabetic and non-diabetic) CKD patients. We clearly posit that there is this overarching impetus to arrive at the inference that multiple, disparately diverse and independent pathways, including any veritable combination of the mechanisms that we examine in this review, and many more others yet to be identified, do concurrently and asymmetrically contribute to CKD initiation and propagation to end-stage renal disease (ESRD) in our CKD patients. We conclude that current knowledge of CKD initiation and progression to ESRD, the natural history of CKD and the impacts of acute kidney injury on this continuum remain in their infancy and call for more research. Finally, we suggest a new classification scheme for renoprotective agents: (1) the single-pathway blockers that block a single putative pathogenetic pathway involved in CKD progression, as typified by ACE inhibitors and/or ARBs, and (2) the multiple-pathway blockers that are able to block or antagonize the effects of multiple pathogenetic pathways through their ability to simultaneously block, downstream, the effects of several pathways or mechanisms of CKD to ESRD progression and could therefore concurrently interfere with several unrelated upstream pathways or mechanisms. We surmise that maybe the ideal and truly renoprotective agent, clearly a multiple-pathway blocker, is on the horizon. This calls for more research efforts from all.