What is the basal insulin dose?

Understanding Basal Insulin Dose

Basal insulin dose refers to the amount of long-acting insulin administered to control blood glucose levels between meals and overnight by restraining hepatic glucose production and limiting hyperglycemia. 1

What Basal Insulin Does

Basal insulin serves as the foundation of insulin therapy by:

• Controlling fasting glucose levels
• Restraining hepatic glucose production
• Limiting hyperglycemia during overnight periods and between meals 1
• Providing background insulin coverage throughout a 24-hour period

Dosing Guidelines

Initial Dosing

• For type 2 diabetes:

  • Starting dose: 0.1-0.2 units/kg/day 1
  • Example: A 70 kg person would start with 7-14 units daily
  • Typically administered once daily at bedtime

• For type 1 diabetes:

  • Typically 50% of total daily insulin requirement 1
  • Total daily insulin requirements usually range from 0.4-1.0 units/kg/day
  • Example: A 70 kg person with type 1 diabetes might need 28-35 units of total insulin, with about 14-17.5 units as basal insulin

Administration Timing

• Most commonly administered once daily at bedtime
• Can be administered at breakfast or dinner time with similar glycemic control 2
• Morning administration may be associated with fewer nocturnal hypoglycemic events 2

Types of Basal Insulin

1. Intermediate-acting:

   • NPH insulin (human)
   • Duration: 12-18 hours
   • May require twice-daily dosing

2. Long-acting analogs:

   • Glargine (U-100)
   • Detemir
   • Duration: Up to 24 hours
   • Reduced risk of symptomatic and nocturnal hypoglycemia compared to NPH 1

3. Longer-acting analogs:

   • U-300 glargine
   • Degludec
   • Duration: Beyond 24 hours
   • Lower hypoglycemia risk compared to U-100 glargine 1

Clinical Considerations

Signs of Overbasalization

Be alert for signs of excessive basal insulin dosing:

• Basal dose exceeding 0.5 units/kg
• High bedtime-to-morning glucose differential (≥50 mg/dL)
• Hypoglycemia (aware or unaware)
• High glucose variability 1

Adjusting Basal Insulin

• Titrate doses over days to weeks based on fasting glucose levels
• For patients with type 1 diabetes, maintain basal insulin coverage at all times
• When adding significant prandial insulin doses, consider decreasing basal insulin 1

Common Pitfalls

1. Confusing basal with bolus insulin:

   • Basal insulin is not meant to cover meals or correct high glucose spikes
   • Prandial (bolus) insulin is needed for mealtime coverage

2. Inappropriate timing:

   • While traditionally given at bedtime, basal insulin can be administered at different times with similar efficacy 2

3. Overbasalization:

   • Relying too heavily on basal insulin when prandial coverage is needed
   • Can lead to hypoglycemia and weight gain

4. Failure to adjust:

   • Basal insulin needs may change with weight changes, activity levels, and illness
   • Regular monitoring and adjustment are necessary

Basal insulin is a foundational component of insulin therapy that provides background insulin coverage throughout the day, helping maintain glucose control between meals and overnight by primarily suppressing hepatic glucose production.