What is the comparison between 70/30 (pre-mixed insulin) and Glargine (insulin glargine) in terms of indications, price, availability, and effectiveness for diabetes management?

Comparison of 70/30 Premixed Insulin vs Insulin Glargine

Insulin glargine is the superior choice for most patients with diabetes due to significantly lower hypoglycemia risk (particularly nocturnal), more physiologic basal coverage, and greater dosing flexibility, despite higher cost. 1

Indications

Insulin Glargine

• Type 1 diabetes: Once-daily basal insulin in combination with prandial (mealtime) insulin 1
• Type 2 diabetes: Can be used as monotherapy or combined with oral agents, GLP-1 RAs, or prandial insulin 1
• Hospital setting: Preferred for basal-bolus regimens in non-ICU patients 1

70/30 Premixed Insulin

• Type 2 diabetes only: Provides both basal and prandial coverage in a fixed ratio (70% intermediate-acting NPH, 30% regular insulin) 1
• Limited flexibility: Requires consistent meal timing and content due to NPH peak at 6-8 hours 1, 2
• Simplification strategy: May be considered when converting from basal insulin for patients who cannot manage multiple daily injections 1

Effectiveness

Glycemic Control

• Equivalent A1C reduction: Both achieve similar glycemic control when properly dosed 1
• Postprandial coverage: 70/30 addresses postprandial glucose but with less flexibility than basal-bolus regimens 1
• Fasting glucose: Glargine provides superior fasting glucose control with flatter 24-hour profile 3, 4

Hypoglycemia Risk: Critical Safety Difference

• 70/30 has unacceptably high hypoglycemia rates: The Bellido trial was stopped early due to 64% hypoglycemia rate with premixed 70/30 versus only 24% with glargine-based basal-bolus 1
• Glargine reduces overall hypoglycemia by 11% (p=0.0006) compared to NPH-based regimens 5
• Nocturnal hypoglycemia reduced by 26% with glargine (p<0.0001) 5
• Severe hypoglycemia reduced by 46% with glargine (p=0.0442) 5
• Severe nocturnal hypoglycemia reduced by 59% with glargine (p=0.0231) 5

Price and Availability

Cost Comparison

• Human 70/30 premixed insulin: $25-35 per vial at some pharmacies, making it the most affordable option 2
• Insulin glargine (brand): Significantly more expensive at baseline 2
• Insulin glargine follow-on products (Basaglar): Median NADAC approximately $95 per 1,000 units for vials, representing a middle-ground option 2
• Medicare Part D cap: $35 monthly maximum out-of-pocket for insulin may equalize costs for Medicare patients 2

Availability

• Both widely available: 70/30 and glargine are stocked at most pharmacies 2
• Formulation options: Glargine available as U-100, U-300; 70/30 available as human insulin or analog versions 1, 2

Clinical Decision Algorithm

Choose Insulin Glargine When:

• Patient has type 1 diabetes (glargine is standard of care) 1
• Patient has irregular meal schedules requiring flexibility 1
• Patient has history of hypoglycemia or hypoglycemia unawareness 5
• Patient is hospitalized (glargine-based basal-bolus preferred) 1
• Cost is not prohibitive or patient has Medicare Part D coverage 2
• Patient requires titration flexibility independent of meal coverage 4

Consider 70/30 Premixed Only When:

• Patient has type 2 diabetes with very regular meal patterns 1
• Cost is absolutely prohibitive and patient lacks insurance coverage 2
• Patient cannot manage multiple daily injections and refuses GLP-1 RA options 1
• Patient is transitioning from basal-only insulin and needs simplified prandial coverage 1

Upgrade from 70/30 to Glargine If:

• Patient experiences recurrent hypoglycemia, especially nocturnal 1, 5
• Patient needs meal schedule flexibility 1
• Patient requires hospitalization (switch to basal-bolus with glargine) 1

Critical Pitfalls to Avoid

• Never use 70/30 in hospitalized patients: The 64% hypoglycemia rate in the Bellido trial demonstrates this is unsafe 1
• Do not assume cost savings justify hypoglycemia risk: Severe hypoglycemia has significant morbidity and mortality implications that outweigh medication cost differences 5
• Recognize 70/30 limitations: The fixed ratio and NPH peak require rigid meal timing; patients with variable schedules will have poor outcomes 1, 2
• Account for NPH component: The 70% NPH in 70/30 peaks 6-8 hours post-injection, creating hypoglycemia risk if meals are delayed 1, 2
• Consider modern alternatives: Before choosing 70/30, evaluate whether basal insulin plus GLP-1 RA would provide better outcomes with lower hypoglycemia risk 1