Preferred Insulin in Chronic Kidney Disease
Insulin glargine (first- or second-generation long-acting basal insulin analogues) is the preferred insulin for patients with CKD due to superior glycemic control and significantly reduced nocturnal hypoglycemia compared to NPH insulin, particularly in advanced CKD stages 3-4. 1
Insulin Selection and Rationale
First-Line Insulin Choice
Long-acting basal insulin analogues (insulin glargine U100, insulin degludec) are preferred over NPH insulin because they provide more predictable pharmacokinetics with no peak action, reducing hypoglycemia risk in patients with impaired renal insulin clearance 1, 2
Insulin glargine U100 demonstrated a 0.91% reduction in HbA1c (p<0.001) and 3-fold lower nocturnal hypoglycemia rates compared to NPH insulin in patients with type 2 diabetes and CKD stages 3-4 1
Second-generation basal insulins (insulin degludec) show comparable efficacy to insulin glargine across all CKD stages (G1-G5), with similar safety profiles 3
Critical Dosing Adjustments by CKD Stage
CKD Stages 1-3 (eGFR ≥30 mL/min/1.73 m²):
- Reduce basal insulin dose by 25-30% for type 1 diabetes patients 3
- Monitor closely as insulin clearance begins to decline 3
CKD Stage 4-5 (eGFR <30 mL/min/1.73 m²):
- Reduce total daily insulin dose by 50% for type 2 diabetes patients 3
- Reduce total daily insulin dose by 35-40% for type 1 diabetes patients 3
- Further reduce basal insulin by 25% on pre-hemodialysis days 3
Advanced CKD/Dialysis:
- Insulin requirements may decrease substantially or be eliminated due to reduced renal insulin clearance 4
- Patients require individualized dose titration with frequent monitoring due to fluctuating insulin resistance and unpredictable metabolism 4, 2
Insulin as Part of Comprehensive CKD-Diabetes Management
When Insulin Becomes Necessary
Insulin therapy is often required when eGFR <30 mL/min/1.73 m² because most oral antidiabetic agents become contraindicated or lose efficacy 3, 5
For type 1 diabetes, insulin remains the only approved therapy across all CKD stages 3
For type 2 diabetes, insulin is added when GLP-1 receptor agonists, SGLT2 inhibitors, and DPP-4 inhibitors fail to achieve glycemic targets or are contraindicated 3
Integration with Non-Insulin Therapies
Before initiating insulin, optimize SGLT2 inhibitors (if eGFR ≥20 mL/min/1.73 m²) and GLP-1 receptor agonists as these provide kidney and cardiovascular protection independent of glycemic effects 3, 5
When adding insulin to patients already on insulin secretagogues (sulfonylureas), reduce or discontinue the sulfonylurea to prevent severe hypoglycemia 3
Metformin must be discontinued when eGFR <30 mL/min/1.73 m² before insulin intensification 3
Critical Safety Considerations
Hypoglycemia Risk Management
Patients with CKD stages 4-5 and those on dialysis face the highest hypoglycemia risk due to impaired renal gluconeogenesis and reduced insulin clearance 3, 5
Close monitoring and patient education on hypoglycemia recognition and treatment are mandatory when initiating or adjusting insulin in advanced CKD 3
Consider continuous glucose monitoring (CGM) over point-of-care testing in dialysis patients, as CGM provides better detection of asymptomatic and nocturnal hypoglycemia 3
Common Pitfalls to Avoid
Never use NPH insulin as first-line in CKD patients due to unpredictable peaks and significantly higher nocturnal hypoglycemia rates 1
Avoid first-generation sulfonylureas (chlorpropamide, tolazamide, tolbutamide) entirely in CKD due to prolonged hypoglycemia risk from active metabolites 5, 6
Do not rely solely on HbA1c for glycemic monitoring in dialysis patients as it may be falsely low; correlate with CGM glucose management indicator when possible 3
Reduce insulin doses proactively as eGFR declines—waiting for hypoglycemia to occur before adjustment is dangerous 3, 5