How to manage a patient with impaired renal function and diabetes?

Management of Patients with Impaired Renal Function and Diabetes

For patients with diabetes and chronic kidney disease (CKD), first-line therapy should include metformin and an SGLT2 inhibitor for those with eGFR ≥30 mL/min/1.73 m², along with comprehensive management of blood pressure, lipids, and lifestyle modifications. 1

Medication Management Algorithm

Glycemic Control

1. First-line therapy (eGFR dependent):

   • Metformin:
     • eGFR ≥45 mL/min/1.73 m²: Standard dose
     • eGFR 30-45 mL/min/1.73 m²: Reduce dose
     • eGFR <30 mL/min/1.73 m²: Discontinue 1
   • SGLT2 inhibitor:
     • eGFR ≥30 mL/min/1.73 m²: Recommended
     • eGFR <30 mL/min/1.73 m²: Do not initiate 1

2. Additional therapy (if glycemic targets not achieved):

   • GLP-1 receptor agonist: Preferred additional agent due to cardiovascular benefits and potential to prevent macroalbuminuria 1
   • DPP-4 inhibitors: Consider for patients unable to tolerate GLP-1 RAs
   • Insulin: For patients with eGFR <30 mL/min/1.73 m² or on dialysis 1

Blood Pressure Control

1. First-line therapy:

   • ACE inhibitor or ARB: For patients with albuminuria >30 mg/day 2
   • Monitor: Serum creatinine and potassium within 2-4 weeks of initiation
   • Continue: Even if serum creatinine increases up to 30% from baseline 3
   • Caution: Monitor for hyperkalemia, especially with concomitant medications that raise potassium 4

2. Target blood pressure:

   • Without albuminuria: <140/90 mmHg
   • With albuminuria or diabetes: <130/80 mmHg 2

Monitoring and Assessment

1. Regular monitoring:

   • eGFR and albuminuria: At least annually for all patients with diabetes 2
   • HbA1c: Every 6 months for patients not meeting targets; every 12 months for stable patients 1
   • Serum creatinine: At least annually for patients on metformin; more frequently with reduced eGFR 1
   • Lipid profile: At least annually 1

2. Frequency based on CKD stage:

   • G1-G2, A1: Annual monitoring
   • G3a, A1 or G1-G2, A2: 1-2 times per year
   • G4-G5, any A or any G, A3: 3-4 times per year 2

Lifestyle Modifications

1. Diet:

   • Protein intake: Maintain 0.8 g/kg body weight/day for non-dialysis patients 1, 2
   • Sodium intake: <2 g sodium per day (<5 g salt/day) 1, 2
   • Diet quality: High in vegetables, fruits, whole grains, fiber, legumes, plant-based proteins, unsaturated fats, and nuts; lower in processed meats, refined carbohydrates, and sweetened beverages 1

2. Physical activity:

   • Target: Moderate-intensity physical activity for at least 150 minutes per week 1, 2
   • Avoid: Sedentary behavior 1

Lipid Management

• Statin therapy: Recommended for adults ≥50 years with eGFR <60 mL/min/1.73 m² 2
• Monitoring: Measure alanine aminotransferase within 12 weeks of initiating statin therapy 1

When to Refer to a Nephrologist

• eGFR <30 mL/min/1.73 m²: To discuss renal replacement therapy options 1
• Continuously rising UACR levels and/or continuously declining eGFR 1
• Difficult management issues: Anemia, secondary hyperparathyroidism, significant increases in albuminuria despite good blood pressure management, metabolic bone disease, resistant hypertension, or electrolyte disturbances 1

Common Pitfalls and Caveats

1. Metformin:

   • Pitfall: Continuing metformin in patients with eGFR <30 mL/min/1.73 m²
   • Solution: Regularly monitor renal function and discontinue when eGFR falls below 30 mL/min/1.73 m² 1
   • Special consideration: For patients aged 80+ years or those with reduced muscle mass, obtain timed urine collection for creatinine clearance 1

2. ACE inhibitors/ARBs:

   • Pitfall: Discontinuing too quickly when serum creatinine rises
   • Solution: Continue unless serum creatinine increases >30% within 4 weeks or hyperkalemia develops (K+ >5.6 mmol/L) 3
   • Caution: Avoid dual RAS blockade (combining ACE inhibitors with ARBs) due to increased risk of hyperkalemia and acute kidney injury 4

3. NSAIDs:

   • Pitfall: Using NSAIDs in patients with diabetes and CKD
   • Solution: Avoid NSAIDs as they can cause deterioration of renal function, especially in elderly or volume-depleted patients 4

4. Hypoglycemia risk:

   • Pitfall: Failing to adjust medication doses as renal function declines
   • Solution: Monitor more frequently and adjust doses of insulin and other medications that may accumulate with declining renal function 5

By following this comprehensive management approach, you can help slow CKD progression, reduce cardiovascular risk, and improve outcomes in patients with diabetes and impaired renal function.