How modern kidney protection works, from RAAS blockade to SGLT2 inhibitors, finerenone, GLP-1 receptor agonists, and disease specific therapy. An interactive education module for the NNH care team on preserving nephrons across the CKD journey.
Developed by Craig G. Hurwitz, MD
[One sentence guiding the clinician on what they're choosing.]
[Primary reference — author list. Title in italics. Journal year;volume(issue):pages. doi:...]
[Secondary reference — e.g. relevant society guideline.]
A healthy adult starts with roughly one to two million nephrons. Chronic kidney disease is the slow, silent loss of those nephrons. The central job of nephrology is not to regrow them, it is to slow how fast they are lost. Modern care does this by layering therapies that each protect the remaining nephrons in a different way.
Standard RAAS therapy alone slows decline, but nephron loss continues.
For decades, blocking the renin angiotensin aldosterone system was the only proven lever.
Each added layer protects nephrons through a distinct mechanism. Modern CKD care is strategic combination therapy, not a single drug.
Many forces push a nephron toward scarring: high pressure inside the glomerulus, protein spilling into the urine, inflammation, fibrosis, and the metabolic stress of diabetes and obesity. Turn stressors on to see the injury signal climb, then add renoprotective layers and watch it fall. This is a conceptual teaching model, not a measured value.
Add stressors and protective layers to explore how injury accumulates and is relieved.
For decades, blocking the renin angiotensin aldosterone system has been the cornerstone of renoprotection. ACEi and ARBs relax the efferent arteriole, the vessel leaving the glomerulus. That lowers the pressure inside the filter and reduces the protein leaking into the urine. Toggle the therapy to see the mechanism.
KDIGO 2024 recommends an ACEi or ARB as first line for CKD with hypertension and/or albuminuria, particularly in diabetic kidney disease.
A limited, stable rise in serum creatinine after starting an ACEi or ARB is expected. It reflects the intended drop in pressure inside the glomerulus, which is the protective effect, not kidney damage. Function typically settles at a new baseline.
What is different: a large or steadily climbing creatinine, especially with volume depletion, hypotension, or a possible renovascular cause. That pattern should prompt evaluation rather than simple reassurance.
Teaching point: an expected, plateauing rise is a reason to continue, not to stop.
Normally the macula densa senses sodium arriving in the tubule and tells the afferent arteriole how wide to open. In CKD, too much sodium is reabsorbed early in the proximal tubule, so the macula densa is fooled into thinking flow is low. The afferent stays wide open, pressure inside the glomerulus climbs, and hyperfiltration sets in. SGLT2 inhibitors block some of that early sodium reabsorption, so the signal reaches the macula densa and the brake comes back on. This is a conceptual mechanism view.
Set up a patient, then stack therapies. Each layer wraps the nephron in another ring of protection through a different mechanism. The albuminuria and slope panels are conceptual teaching models, labeled illustrative, not predictions for any individual patient.
Each layer lowers protein in the urine through a distinct pathway. Reductions compound when layers are combined.
ACE inhibitors and ARBs blunt angiotensin, but mineralocorticoid receptor overactivation keeps driving inflammation and fibrosis. Finerenone, a nonsteroidal MRA, targets that residual pathway. Add each therapy to see how scarring slows. The fibrosis model is conceptual; the decision aid below mirrors initiation rules and should be confirmed against your protocol.
GLP-1 receptor agonists protect the kidney both directly and through metabolic effects: weight loss, better glucose control, lower blood pressure, and reduced inflammation. Tap an effect to see how it contributes, and move the weight slider to see metabolic risk fall. The risk meter is a conceptual illustration.
FLOW enrolled type 2 diabetes with CKD and was stopped early for efficacy. Liraglutide (LEADER), dulaglutide (REWIND), and efpeglenatide (AMPLITUDE-O) also showed kidney benefit; a meta-analysis of 8 trials found a 21 percent reduction in composite kidney outcomes. Ozempic now carries an FDA kidney indication in type 2 diabetes with CKD.
Almost every proteinuric kidney disease shares the same renoprotective backbone: maximized RAS inhibition and an SGLT2 inhibitor. What changes is the disease-specific layer added on top. Select a diagnosis to see how the plan adapts.
Select a diagnosis above to build its renoprotection plan.
Renoprotection is increasingly personalized. The shared backbone buys broad protection, and the disease-specific layer targets the mechanism unique to each diagnosis.
Work through three patients. Choose the renoprotective layers you would add, then reveal the NNH approach and the reasoning. These are teaching cases that reflect the evidence in this module.
Ten questions across mechanisms, trial interpretation, medication selection, and safety monitoring. Earn your badge: Bronze, Silver, Gold, or Nephron Guardian.
Layered renoprotection did not arrive all at once. Each era added a new mechanism on top of the last. Walk the timeline to see why combination therapy feels inevitable in hindsight.
Modern CKD care is no longer one drug. It is a strategy: a shared renoprotective backbone, layered additions by mechanism, and a disease-specific top layer matched to the patient.
