Basal insulin 101: the quiet, background insulin
Basal insulin is a continuously-acting insulin that resembles the natural insulin produced by a healthy pancreas. It supplies energy to the body's cells and controls blood sugar throughout the day, both during and between meals. According to the American Diabetes Association, basal insulin or 'background insulin' is a long-acting insulin type. Delivering a steady, low level of insulin to regulate the body's blood glucose levels, basal insulin mimics the body's own natural insulin mechanism. Basal insulin may also refer to the slow and steady rate of insulin delivery via an insulin pump.
Basal insulin types
Basal insulin types vary by their rate of absorption. Slow-absorbing basal insulins may be active in the body from 10 to 24 hours, depending on the type. The nonprofit healthcare cooperative Group Health describes the three types of basal insulin:
- NPH insulin: An intermediate-acting insulin, NPH typically begins to work in 2 hours, peaks in 6 to 8 hours and remains active for 10-16 hours
- Glargine insulin: A long-acting insulin, Glargine begins to act in 2 hours and holds steady for 20 to 24 hours
- Determir insulin: The intermediate-acting insulin Detemir is also relatively peakless, and lasts approximately 12 hours
In addition, patients have the option to take a combination insulin, which delivers a mixed dose of intermediate- or fast-acting and long-acting insulin. Combination insulin offers the potential advantage of fewer shots, but may produce stronger peaks.
Patients can manage their type 1 or type 2 diabetes by administering a constant, low level of basal insulin. Basal insulin may be continuously monitored via an insulin pump, or manually injected with an insulin shot or pen. Either method produces a steady flow of background insulin throughout the day, matching the body's natural release of insulin.
American Diabetes Association, "How Do Insulin Pumps Work?"
GroupHealth, "Types of Insulin and How They Work"
Dr. Fran Cogen, "Diabetes and Insulin: Types and Application"