What is the basal bolus insulin regimen?

Basal-Bolus Insulin Regimen Explained

The basal-bolus insulin regimen is the most effective approach for achieving optimal glycemic control in diabetes management, consisting of once or twice daily long-acting basal insulin to maintain blood glucose between meals and overnight, combined with rapid-acting insulin before meals to control postprandial glucose excursions. 1

Components of the Basal-Bolus Regimen

Basal Insulin

• Provides continuous background insulin coverage to control blood glucose between meals and overnight 1
• Typically administered as a long-acting insulin analog (e.g., glargine) once or twice daily 1
• Usually accounts for approximately 50% of the total daily insulin requirement 1
• Aims to maintain stable blood glucose levels during fasting periods 1

Bolus (Prandial) Insulin

• Rapid-acting insulin administered before meals to control postprandial glucose excursions 1
• Usually accounts for the remaining 50% of total daily insulin, divided between meals 1
• Dose is calculated based on carbohydrate content of meals and current blood glucose levels 1
• May include additional corrective doses for hyperglycemia 1

Dosing Guidelines

Initial Dosing

• For insulin-naive patients: Total daily insulin dose of 0.3-0.5 units/kg 1
• Half allocated to basal insulin, half to rapid-acting insulin divided across meals 1
• For patients already on higher insulin doses (≥0.6 units/kg/day): Consider 20% reduction in total daily dose when transitioning to hospital setting to prevent hypoglycemia 1
• Lower doses (0.1-0.25 units/kg/day) recommended for patients at higher risk of hypoglycemia (older patients >65 years, renal failure, poor oral intake) 1

Dose Adjustments

• Basal insulin dose is titrated based on fasting blood glucose levels 1
• Bolus insulin is adjusted based on pre-meal blood glucose and carbohydrate content of meals 1
• Correction doses of rapid-acting insulin are added when blood glucose exceeds target range 1

Clinical Effectiveness

• Randomized trials consistently show better glycemic control with basal-bolus approach compared to sliding scale insulin alone in type 2 diabetes 1
• Associated with reduction in complications including postoperative wound infection, pneumonia, bacteremia, and acute renal and respiratory failure 1
• In type 1 diabetes, basal-bolus regimens result in more stable glycemic control and less hypoglycemia compared to regimens using intermediate and short insulin 1
• The basal-bolus approach is particularly beneficial after the honeymoon period in type 1 diabetes 1

Variations of the Basal-Bolus Approach

Basal-Plus Regimen

• A simplified version of basal-bolus using basal insulin plus a single mealtime insulin injection 1, 2
• Consists of a single dose of basal insulin (0.1-0.25 units/kg/day) with corrective doses of rapid-acting insulin 1
• Particularly useful for patients with mild hyperglycemia, decreased oral intake, or those undergoing surgery 1
• Can be as effective as standard basal-bolus with less risk of hypoglycemia 2, 3
• Often used as a stepping stone to full basal-bolus therapy 4, 3

Stepwise Approach

• Start with basal insulin once daily 1
• Add a single prandial insulin bolus before the meal causing the highest postprandial glucose excursion 4, 3
• Add additional boluses at other meals as needed when postprandial glucose remains elevated 4
• Eventually may progress to standard basal-bolus with three pre-meal injections 4

Monitoring and Safety

• Requires frequent blood glucose monitoring (at least 4 tests per day) 1
• Risk of hypoglycemia is 4-6 times higher with basal-bolus insulin than with sliding scale insulin therapy alone 1
• Incidence of mild hypoglycemia (blood glucose ≤3.9 mmol/L or 70 mg/dL) is about 12-30% in controlled settings 1
• Severe hypoglycemia is relatively rare in controlled settings but may occur more frequently in real-world practice 1

Common Pitfalls and Considerations

• Sliding scale insulin alone should not be used in patients with type 1 diabetes 1
• Premixed insulin therapy has been associated with unacceptably high rates of hypoglycemia and is not recommended in the hospital setting 1
• Two or three doses of mixed rapid-acting or short-acting insulin with intermediate-acting insulin generally cannot maintain target A1C levels for most patients with type 1 diabetes 1
• For young children with unpredictable eating patterns, administering rapid-acting insulin after meals may help match insulin to actual food intake 1
• Coordinating basal and bolus insulin delivery (rather than treating them independently) may improve postprandial control, especially for larger meals 5, 6