In a patient with type 1 diabetes, which is better: insulin ryzodec twice a day, insulin glargine (Lantus) once daily and insulin aspart (Actrapid) three times a day, or insulin mixtard twice daily?

Optimal Insulin Regimen for Type 1 Diabetes

For type 1 diabetes, insulin glargine (Lantus) once daily combined with rapid-acting insulin (such as insulin aspart, not Actrapid which is regular human insulin) three times daily before meals is the superior choice over both Ryzodeg twice daily and Mixtard twice daily. 1, 2

Why Basal-Bolus Therapy is the Gold Standard

The American Diabetes Association explicitly recommends that most people with type 1 diabetes should be treated with multiple daily injections of prandial and basal insulin (or continuous subcutaneous insulin infusion via pump). 1, 2 This basal-bolus approach provides:

• Separate control of basal and prandial insulin needs, allowing independent titration of each component based on fasting glucose patterns and postprandial responses 3
• Approximately 50% of total daily insulin as basal (Lantus) and 50% divided among meals as rapid-acting insulin 2, 3
• Superior glycemic control with lower hypoglycemia risk compared to premixed formulations 4, 5

Why Rapid-Acting Analogs Over Regular Human Insulin

The American Diabetes Association specifically recommends that most individuals with type 1 diabetes should use rapid-acting insulin analogs to reduce hypoglycemia risk. 1, 2 This means:

• Use insulin aspart, lispro, or glulisine (rapid-acting analogs) rather than Actrapid (regular human insulin) 2, 4
• Rapid-acting analogs provide better postprandial glucose control, greater convenience with meal-time dosing, and lower risk of late postprandial hypoglycemia compared to regular human insulin 4, 5

Why Not Ryzodeg (Degludec/Aspart 70/30)?

While Ryzodeg contains the ultra-long-acting insulin degludec combined with rapid-acting aspart in a 70/30 fixed ratio:

• Premixed insulin formulations have largely been eliminated from type 1 diabetes management because they cannot provide the flexibility needed for optimal glycemic control 6
• Basal-bolus injections have proved superior to premixed insulin in type 1 diabetes 6
• Fixed ratios prevent independent adjustment of basal versus prandial components, which is essential for matching insulin to varying carbohydrate intake, activity levels, and glucose patterns 2, 3

Why Not Mixtard (NPH/Regular 30/70)?

Mixtard is an older premixed formulation combining NPH and regular human insulin:

• Contains regular human insulin rather than rapid-acting analogs, which increases hypoglycemia risk 1, 2
• NPH has a pronounced peak 4-5 hours after injection with only 10-15 hours duration, creating unpredictable glucose patterns 5
• Cannot separately adjust basal and prandial components to match individual needs 3
• Modern basal analogs like glargine provide superior basal coverage with a peakless 24-hour action profile, reducing nocturnal hypoglycemia by 25% compared to NPH 5, 7

Practical Implementation of the Recommended Regimen

Start with 0.5 units/kg/day total daily insulin dose in metabolically stable patients: 2

• 50% as once-daily glargine (Lantus) administered at bedtime or a consistent time daily 2, 3
• 50% divided among three meals as rapid-acting insulin analog (aspart, lispro, or glulisine) given immediately before eating 2, 3

Essential patient education components: 2

• Carbohydrate counting to match prandial insulin doses to meal content 2
• Correction dose calculations based on premeal glucose levels using insulin sensitivity factors 2, 3
• Adjustment for anticipated physical activity 2

Common Pitfalls to Avoid

• Do not use regular human insulin (Actrapid) when rapid-acting analogs are available – this increases hypoglycemia risk unnecessarily 1, 2
• Do not rely on premixed insulins in type 1 diabetes – the inability to independently adjust basal and prandial components compromises glycemic control 6
• Do not use NPH-based regimens when long-acting analogs are available – glargine provides more stable basal coverage with less nocturnal hypoglycemia 5, 7