What is basal insulin?

From the Guidelines

Basal insulin is a long-acting insulin that provides a steady, background level of insulin throughout the day and night to help control blood glucose levels between meals and during sleep, as stated in the most recent guidelines 1.

Key Characteristics of Basal Insulin

• Common basal insulins include insulin glargine (Lantus, Toujeo), insulin detemir (Levemir), insulin degludec (Tresiba), and NPH insulin (Humulin N, Novolin N) 1.
• These are typically injected once or twice daily, depending on the specific type.
• Basal insulin works by mimicking the body's natural baseline insulin production, which helps regulate glucose release from the liver and maintains stable blood sugar levels during fasting periods.

Usage and Dosage

• For people with type 1 diabetes, basal insulin is essential and is used alongside mealtime insulin.
• For those with type 2 diabetes, basal insulin is typically added when oral medications are no longer sufficient to maintain target blood glucose levels.
• The dose is usually started low (often 10 units or 0.1-0.2 units per kilogram of body weight) and adjusted based on fasting blood glucose readings until target levels are achieved 1.

Important Considerations

• Clinicians should be aware of the potential for overbasalization with insulin therapy, which can lead to hypoglycemia and other complications 1.
• Clinical signals that may prompt evaluation of overbasalization include basal dose greater than 0.5 units/kg, high bedtime-to-morning or preprandial-to-postprandial glucose differential, hypoglycemia, and high variability.
• Indication of overbasalization should prompt reevaluation to further individualize therapy 1.

From the FDA Drug Label

Insulin detemir is a soluble, long-acting basal human insulin analog with a relatively flat action profile.

Basal insulin is a type of insulin that is designed to provide a steady, background level of insulin activity throughout the day, typically lasting for 20-24 hours. It is often used to control blood sugar levels between meals and during sleep. Examples of basal insulins include insulin glargine and insulin detemir, as described in the provided drug labels 2 and 3.

From the Research

Definition of Basal Insulin

• Basal insulin refers to the background level of insulin produced by the pancreas during fasting periods, with the aim of matching this pattern as closely as possible in insulin therapy to avoid hypoglycemia 4.
• The primary goal of basal insulin therapy is to provide a steady, reliable level of insulin coverage, mimicking the body's natural basal insulin production 5.

Characteristics of Basal Insulins

• Optimal pharmacokinetic and pharmacodynamic properties of long-acting basal insulins include a flat, peak-free activity profile, a duration of action of at least 24 hours, and minimal day-to-day variation 4.
• Established long-acting basal insulins, such as insulin glargine and insulin detemir, exhibit similar glycemic control to intermediate-acting insulins but with reduced hypoglycemia risk 4, 6, 7.

Types of Basal Insulins

• Traditional long-acting insulins, such as NPH insulin, have been largely replaced by newer analogs like insulin glargine and insulin detemir, which offer improved pharmacokinetic and pharmacodynamic profiles 4, 7.
• Ultra-long-acting insulins, such as insulin degludec, and newer products like basal insulin peglispro, are being developed to further improve glycemic control and reduce hypoglycemia risk 4, 8.
• Once-weekly insulins, including basal insulin icodec and basal insulin Fc, are currently in clinical development, offering potential benefits in terms of treatment adherence and reduced treatment burden 8.

Clinical Implications

• Basal insulin therapy is a fundamental component of treatment for patients with type 1 and type 2 diabetes, with the goal of achieving optimal glycemic control while minimizing hypoglycemia and other side effects 4, 5.
• The choice of basal insulin should be individualized based on patient characteristics, lifestyle, and treatment goals, with consideration of factors such as duration of action, pharmacokinetic variability, and cost 4, 7.