#KidneyWk 2015: Albuminuria as a Treatment Target in CKD: Reviewing the Current Guidelines in CKD

This lecture was given by Dr. Kunihiro Matsushita, a clinical epidemiologist affiliated with Johns Hopkins Bloomberg School of Public Health, Welch Center for Prevention, Epidemiology, and Clinical Research, as well as the CKD Prognosis Consortium Data Coordinating Center. He started by citing this “Controversies in Nephrology: Albuminuria is an appropriate therapeutic target in patients with CKD: The Pro View” and the con view that was recently published in CJASN.

Albuminuria is a cause of kidney damage
Albuminuria is a predictor of clinical kidney outcomes In agreement
Albuminuria is dealt with as a treatment target in the KDIGO guidelines for glomerulonephritis Albuminuria is used for guiding treatment but not as a target except for uptitrating RAASi to target proteinuria < 1 gm/day in IgA nephropathy.
Drug-induced reduction of albuminuria correlates with reduced risk of clinical kidney outcomes Reduced albuminuria may merely reflect responsiveness to some treatments (e.g., RAASi)
All the above support albuminuria as a surrogate of kidney endpoint for clinical trials No sufficient evidence for albuminuria as a surrogate endpoint for clinical trials

·  Unlike GFR, not necessarily on a direct pathway

·  Several interventions (e.g., diuretics, etc.) reduce albuminuria but not ESRD risk

Credit: Table from Dr. Matsushita’s presentation and reused with his permission.

We have to understand however, that whenever we refer to “treatment target,” there can be several interpretations. Is it:

  1. Target goal of treatment?
  2. Target for preventing progression?
  3. Surrogate endpoint for clinical trials?
  4. Guidance of treatment?

Dr Matsushita talked about other biomarkers in comparison to albuminuria in light of these other interpretations.

BP YES (< 140/90 in general) YES (to achieve target goal) YES YES (to achieve target goal)
LIPIDS NO (new AHA/ACC guidelines or KDIGO Lipid guidelines) NO YES YES (included in AHA/ACC CVD risk calculator)
GFR NO YES (BOP control, RAASi, DM control, immunosuppressive therapy for some glomerulonephritides) YES (halving = doubling of serum creatinine and discussion of milder declines of 30-490%) YES (eg, tighter BP control in KDIGO BP guidelines, statin if age ≥ 50 years in KDIGO Lipid guidelines)
YES (in some glomerulonephritis, eg, IgA nephropathy, idiopathic membranous nephropathy) ? (KDIGO guidelines focus on GFR for defining CKD progression) Some data support but not yet conclusive YES (adherence for clinical guidelines for albuminuria assessment needs to be improved)

Credit: Table from Dr. Matsushita’s presentation and reused with his permission.

Taking all of this into consideration, I agree with Dr. Fried and Dr. Lewis’ supposition that “at this time, we should conclude that albuminuria is therefore, a biomarker but not a surrogate endpoint or target for treatment. We may be doing our patients more harm than good by targeting albuminuria.”

Post by Dr. Edgar Lerma, AJKD Blog Advisory Board member.

Check out all of AJKD Blog’s coverage of Kidney Week 2015! 

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