What is the basal and bolus (Bolus, referring to a type of insulin administration) insulin regimen?

From the Guidelines

A basal and bolus insulin regimen is the most effective approach to achieve optimal glycemic control, reduce morbidity, and improve quality of life for individuals with diabetes, as it mimics normal pancreatic function by providing steady background insulin and addressing mealtime glucose excursions. This regimen consists of a long-acting insulin (basal) taken once or twice daily to provide background insulin coverage, combined with rapid-acting insulin (bolus) taken before meals to cover carbohydrate intake and correct high blood glucose 1. Common basal insulins include glargine (Lantus, Toujeo), detemir (Levemir), degludec (Tresiba), and NPH (Humulin N, Novolin N), typically started at 0.1-0.2 units/kg/day.

• Key considerations for implementing a basal and bolus insulin regimen include:
  • Monitoring blood glucose regularly to adjust insulin doses based on patterns
  • Counting carbohydrates accurately to determine bolus insulin doses
  • Using an insulin-to-carbohydrate ratio (typically 1 unit per 10-15g carbohydrate) and a correction factor (typically 1 unit lowers glucose by 50 mg/dL) to calculate bolus insulin doses
  • Adjusting insulin doses based on individual patient needs and response to therapy
  • Considering the use of newer basal insulins, such as U-300 glargine or degludec, which may convey a lower hypoglycemia risk compared with U-100 glargine 1
• The benefits of a basal and bolus insulin regimen include:
  • Improved glycemic control, with reduced risk of microvascular and macrovascular complications
  • Increased flexibility in meal timing and composition, allowing for a more normal lifestyle
  • Reduced risk of hypoglycemia, particularly with the use of newer basal insulins
  • Improved quality of life, with reduced symptoms and improved overall well-being
• In patients who are not achieving glycemic targets with basal insulin alone, adding bolus insulin before meals can help to improve glycemic control, as outlined in the 2017 American Diabetes Association standards of medical care in diabetes 1.

From the FDA Drug Label

In two clinical studies (Studies A and B), adult patients with type 1 diabetes (Study A, n=585, Study B n=534) were randomized to 28 weeks of basal-bolus treatment with Insulin Glargine or NPH insulin. Regular human insulin was administered before each meal Insulin Glargine was administered at bedtime. NPH insulin was administered either as once daily at bedtime or in the morning and at bedtime when used twice daily. In another clinical study (Study C), patients with type 1 diabetes (n=619) were randomized to 16 weeks of basal-bolus treatment with Insulin Glargine or NPH insulin. Insulin lispro was used before each meal. Insulin Glargine was administered once daily at bedtime and NPH insulin was administered once or twice daily. In a randomized, controlled clinical study (Study F), in adult patients with type 2 diabetes not using oral antidiabetic medications (n=518), a basal-bolus regimen of Insulin Glargine once daily at bedtime or NPH insulin administered once or twice daily was evaluated for 28 weeks. Regular human insulin was used before meals, as needed.

The basal and bolus insulin regimen is described in the studies as follows:

• Basal insulin: Insulin Glargine was administered once daily at bedtime.
• Bolus insulin: Regular human insulin or insulin lispro was administered before each meal. The studies compared the safety and effectiveness of Insulin Glargine with NPH insulin in patients with type 1 and type 2 diabetes mellitus, using a basal-bolus regimen 2.

From the Research

Basal and Bolus Insulin Regimen

• The basal and bolus insulin regimen is a treatment approach for managing type 2 diabetes mellitus, which involves administering a combination of long-acting basal insulin and rapid-acting insulin at mealtimes 3, 4.
• This regimen has been shown to be effective in improving glycemic control, reducing the risk of complications, and enhancing patient outcomes 3, 5.
• The American Diabetes Association (ADA) recommends early intensification of antihyperglycemic therapy in diabetic patients to achieve and maintain HbA1c goals early 3.

Efficacy and Safety

• Studies have demonstrated that basal-bolus therapy with insulin glargine and insulin lispro provides similar or better glycemic control and leads to less nocturnal hypoglycemia compared to other insulin regimens 4, 5.
• The regimen has also been shown to be safe and effective in pediatric and adult populations with type 1 and type 2 diabetes, as well as in patients with comorbidities 4, 6.
• However, the regimen may be associated with weight gain and hypoglycemia, particularly when mealtime insulin is added to basal insulin 7.

Patient Outcomes

• Patients using basal-bolus insulin therapy have been reported to experience better glycemic control, fewer hypoglycemic events, and less weight gain compared to those using other insulin regimens 5, 6.
• The regimen has also been shown to improve patient satisfaction and quality of life, although some patients may experience treatment-emergent adverse events 7, 6.
• Overall, the basal and bolus insulin regimen is a effective and safe treatment approach for managing type 2 diabetes mellitus, and can be tailored to individual patient needs and abilities 3, 4, 5, 7, 6.