In a 79-year-old man with type 2 diabetes mellitus, hemoglobin A1c 6.4%, microalbuminuria (albumin‑creatinine ratio ~42 mg/g), chronic kidney disease stage 3b (estimated glomerular filtration rate ~44 mL/min/1.73 m²) who is already on empagliflozin and metformin 500 mg once daily, what additional measures should be taken to preserve renal function?

Additional Measures to Preserve Renal Function in a 79-Year-Old with Type 2 Diabetes and CKD Stage 3b

You should immediately add dapagliflozin 10 mg once daily to the patient's regimen, as this provides a 44% reduction in kidney-specific outcomes and a 39% reduction in the composite of sustained eGFR decline, end-stage kidney disease, or cardiovascular/renal death, independent of glycemic control needs. 1, 2

Primary Intervention: Initiate SGLT2 Inhibitor

• Start dapagliflozin 10 mg once daily for cardiorenal protection; at eGFR 44 mL/min/1.73 m², this patient meets the eligibility criterion (eGFR ≥25 mL/min/1.73 m²) for initiation. 1, 2

• The patient's microalbuminuria (UACR ~42 mg/g) qualifies for SGLT2 inhibitor therapy, though the strongest evidence exists for UACR ≥200 mg/g; benefits are still present at lower albuminuria levels. 1, 2

• Do not reduce or discontinue empagliflozin if the patient is already on it—continue the current dose as both empagliflozin and dapagliflozin provide similar cardiorenal protection. 1, 3, 4

• The glucose-lowering effect of SGLT2 inhibitors is minimal at eGFR <45 mL/min/1.73 m², but cardiovascular and renal protective benefits persist and remain the primary therapeutic indication at this level of kidney function. 1, 2

Expected Physiologic Changes and Monitoring

• Anticipate a reversible eGFR dip of 2–5 mL/min/1.73 m² within the first 2–4 weeks after starting the SGLT2 inhibitor; this hemodynamic change reflects reduced intraglomerular pressure and should not prompt discontinuation. 2, 5

• Re-measure eGFR 1–2 weeks after initiation, then every 3–6 months to monitor kidney function trajectory. 1, 2

• After the initial dip, eGFR stabilizes and the long-term decline is slower compared with placebo, with an annual eGFR slope of +0.23 mL/min/1.73 m²/year on empagliflozin versus -1.46 mL/min/1.73 m²/year on placebo. 5

Metformin Dose Adjustment

• Metformin 500 mg once daily is appropriate at eGFR 44 mL/min/1.73 m² and should be continued without further reduction. 1

• If eGFR falls to 30–44 mL/min/1.73 m², limit metformin to a maximum of 1000 mg per day; if eGFR drops below 30 mL/min/1.73 m², discontinue metformin entirely. 1, 6

Renin-Angiotensin System Blockade

• Continue ACE inhibitors or ARBs unchanged when adding an SGLT2 inhibitor; more than 99% of DAPA-CKD participants were on RAS blockade, and the combination provided additive renal protection without requiring dose adjustments. 1, 2

• RAS inhibitors are recommended for patients with albuminuria and hypertension to slow CKD progression. 1

Consider Adding a GLP-1 Receptor Agonist

• If HbA1c remains above target after 3 months on the current regimen, add a GLP-1 receptor agonist (e.g., semaglutide 0.5–1 mg weekly or liraglutide 1.2–1.8 mg daily) for additional cardiovascular protection and glycemic control. 1, 7

• GLP-1 receptor agonists reduce new or worsening nephropathy by 36% and provide complementary cardiovascular benefits to SGLT2 inhibitors. 1, 7

• These agents are safe at eGFR 44 mL/min/1.73 m² and require no dose adjustment. 7

Nonsteroidal Mineralocorticoid Receptor Antagonist

• If albuminuria persists at UACR ≥30 mg/g despite SGLT2 inhibitor therapy and potassium is normal, consider adding a nonsteroidal MRA (e.g., finerenone) for additional renal protection. 1

• This agent provides additive renal benefits when combined with SGLT2 inhibitors and may lessen hyperkalemia risk. 2

Safety Precautions and Patient Education

• Assess volume status before starting the SGLT2 inhibitor and correct any depletion; consider temporarily reducing concurrent diuretic doses in elderly patients to prevent excessive volume loss. 1, 2

• Withhold the SGLT2 inhibitor during acute illness with reduced oral intake, fever, vomiting, or diarrhea, and stop at least 3 days before major surgery or procedures requiring prolonged fasting. 2

• Counsel the patient about genital mycotic infections (occurring in ~6% of SGLT2 inhibitor users versus 1% with placebo) and emphasize daily hygiene. 2

• Warn about the risk of euglycemic diabetic ketoacidosis and advise immediate medical evaluation for malaise, nausea, vomiting, or abdominal pain even when blood glucose is normal. 2

Common Pitfalls to Avoid

• Do not discontinue the SGLT2 inhibitor when eGFR falls below 45 mL/min/1.73 m²; cardiovascular and renal benefits persist despite reduced glycemic efficacy. 1, 2

• Do not stop the drug because of the expected initial eGFR dip in the first 2–4 weeks; this change is hemodynamic and reversible, not indicative of kidney injury. 2, 5

• Do not reduce the SGLT2 inhibitor dose below 10 mg for cardiovascular or renal indications, even if glycemic efficacy wanes at lower eGFR; all outcome trials used the fixed 10 mg dose. 2

• Do not delay initiation of SGLT2 inhibitor therapy based on current HbA1c level; the cardiorenal benefits are independent of glycemic control and should be started promptly. 1, 2

Long-Term Renal Outcomes

• SGLT2 inhibitors reduce the risk of doubling of serum creatinine by 44%, initiation of renal-replacement therapy by 55%, and progression to macroalbuminuria by 38%. 1, 3

• Dapagliflozin slows the rate of eGFR decline and reduces the risk of end-stage renal disease or renal death by 44%. 2, 8

• These benefits are consistent across patients with or without type 2 diabetes, indicating that part of the protective effect operates through pathways unrelated to glucose lowering. 8