What is the best way to improve kidney function in a patient with impaired renal function (50% kidney function) and potential underlying conditions such as hypertension (high blood pressure) and diabetes?

Improving Kidney Function at 50% GFR

Start an ACE inhibitor (like ramipril) or ARB (like losartan) immediately and titrate to the maximum tolerated dose—this is the single most important intervention to slow kidney function decline, particularly if you have any protein in your urine. 1, 2

First Priority: Blood Pressure Control with RAS Blockade

• If you have protein in your urine (albumin ≥30 mg/24 hours), your blood pressure target should be <130/80 mmHg 1, 2
• If you have no protein in your urine, your blood pressure target should be <140/90 mmHg 1, 2
• You will likely need 3-4 different blood pressure medications to reach these targets—single-drug therapy almost never works 1
• ACE inhibitors or ARBs should be titrated to the highest approved dose you can tolerate, not just until blood pressure normalizes 1, 2

Critical monitoring: Your creatinine may rise by up to 30% after starting these medications—this is expected and acceptable. Only reduce the dose if creatinine rises more than 30% or if potassium becomes dangerously high 1

Second Priority: Add SGLT2 Inhibitors (If Diabetic or Have Proteinuria)

• If you have diabetes, add an SGLT2 inhibitor (like empagliflozin or dapagliflozin) to your ACE inhibitor/ARB regimen—these drugs independently slow kidney function decline 2, 3, 4
• SGLT2 inhibitors work even if your kidney function is down to 20% (eGFR ≥20 mL/min/1.73 m²) 2, 3
• Recent evidence shows SGLT2 inhibitors benefit patients with CKD even without diabetes if albuminuria is present 4, 5

Third Priority: Strict Dietary Modifications

• Reduce sodium intake to less than 2 grams per day (less than 5 grams of salt)—this makes blood pressure medications work better and directly reduces protein loss in urine 1, 2, 3
• Limit protein intake to 0.8 grams per kilogram of body weight per day—excessive protein accelerates kidney decline 1, 3
• Adopt a Mediterranean-style diet to reduce cardiovascular risk, which is your biggest mortality threat 2, 3

Fourth Priority: Control Underlying Conditions Aggressively

If you have diabetes:

• Maintain hemoglobin A1c <7% to prevent further kidney damage 1, 4
• Consider adding a GLP-1 receptor agonist (like semaglutide), which reduces albuminuria 4, 5

If you have high cholesterol:

• Start high-intensity statin therapy regardless of your kidney function level 2

Fifth Priority: Eliminate Nephrotoxins

• Stop NSAIDs completely (ibuprofen, naproxen, etc.)—these directly worsen kidney function 1, 3, 4
• Avoid or minimize proton pump inhibitors (omeprazole, pantoprazole) when possible 3, 4
• Stop smoking immediately—smoking accelerates kidney function decline 1
• Be cautious with contrast dye for imaging studies; discuss alternatives with your doctor 1

Sixth Priority: Correct Metabolic Abnormalities

• If you have metabolic acidosis (bicarbonate <22 mmol/L), take oral bicarbonate supplementation—this slows CKD progression 1, 4, 6
• Maintain ideal body weight—obesity accelerates kidney decline 1, 4

When to See a Nephrologist

• See a kidney specialist immediately if your kidney function drops below 30% (eGFR <30 mL/min/1.73 m²) 2, 3, 7
• Also see a nephrologist urgently if you have heavy proteinuria (≥300 mg/g), rapidly declining function, or difficult-to-control blood pressure despite multiple medications 2, 3, 7

Common Pitfalls to Avoid

• Don't combine an ACE inhibitor with an ARB—this combination causes harm without additional benefit 1
• Don't stop your ACE inhibitor/ARB if creatinine rises slightly—up to 30% increase is acceptable and expected 1
• Don't rely on a single medication—kidney protection requires multiple simultaneous interventions 1, 8
• Don't delay treatment—the earlier you start aggressive management, the better your long-term outcomes 1, 9, 8

What You Cannot Reverse

At 50% kidney function, you cannot restore lost nephrons or return to 100% function. However, the interventions above can dramatically slow or even halt further decline, potentially preventing dialysis for many years or indefinitely 4, 6, 9. The goal is preservation and stabilization, not reversal 6, 8.