Goals of insulin therapy

The goal of insulin therapy is to achieve optimal blood glucose control. Healthy, non-diabetic individuals usually maintain a blood glucose profile of 60 – 100 mg/dl overnight and before meals, and <140 mg/dl after meals. Specific blood glucose levels for diabetics are controversial but health providers often recommend overnight and pre-meal blood glucose of <90-130 mg/dl and post-meal blood glucose of <180 mg/dl. https://dtc.ucsf.edu/types-of-diabetes/type1/understanding-type-1-diabetes/basic-facts/treatment-goals/

Usually, the pancreas secretes insulin in response to blood glucose levels. Pancreatic beta cells continuously release a small amount of insulin into the bloodstream. Additional insulin is released in response to a rise in blood glucose that occurs after eating. The continuous release of insulin is known as basal secretion. Insulin released in response to an increase in blood sugar is known as bolus secretion.  Effective insulin regimens are individualized to reflect the patient's health, goals, lifestyle, and self-management ability.

Basal/Bolus Therapy

Insulin therapy closely approximates the normal physiologic condition of continuous low-level insulinemia with steep short duration insulin boluses to cover mealtimes' dietary glucose. The Basal/Bolus diagram on the right demonstrates a typical injection pattern, beginning with an initial injection of long duration "peakless" analog insulin administered around 22:00. The initial dose is followed by a dose of rapid-acting/short duration analog delivered at each mealtime. Basal/Bolus regimens offer a bit more flexibility, but they require more attention to blood glucose monitoring and active self-adjustments of bolus dosing.

An individual's basal insulin requirement can vary due to physical stress, hormonal changes, physical activity, and overall health. Effective insulin regimens are individualized to reflect the patient's health, goals, lifestyle, and self-management ability. Designing an effective insulin regimen involves working with the patient to select a regimen that provides adequate insulin coverage and flexibility regarding calorie intake, mealtime, physical activity, work schedule, other medications, psychosocial and economic factors.

The insulin requirements of diabetic patients reflect the underlying disease.

Type 1 diabetes (T1D) results from the complete or near-complete absence of endogenous insulin secretion. Treatment involves replacing endogenous insulin secretion. In other words, optimum insulin delivery must provide continuous basal release with additional preprandial boluses reflecting the size and type of meals consumed. Basal insulin requirements may vary due to physical stress, hormonal changes, illness, physical activity, and physical fitness level.

Designing an effective insulin regimen involves working with the patient to develop a program that provides adequate insulin coverage and schedule flexibility. Historically, insulin therapy for (T1D) required serial injections of short duration insulin throughout the day. This type of regimen resulted in an increased risk of hypoglycemic events, patient discomfort, and non-compliance

Type 2 Diabetes (T2D) is characterized by progressive insulin resistance, decreased insulin secretion, and reduced hepatic glucose production suppression. Initially, T2D is usually treated by lifestyle modification and oral agents like metformin. However, less than 40% of T2D patients can maintain an A1C of <7. Progressive beta-cell failure often requires the addition of insulin therapy to avoid prolonged hyperglycemia, which can cause glucose toxicity, a potentially reversible impairment in glucose-stimulated insulin secretion (Ripsin et al. 2009).

Summary

Today, rapid and accurate self-monitoring blood glucose devices in conjunction with insulins with various onsets and durations of action offer diabetics much better glycemic control. Intensive therapy utilizing long-duration insulin and multiple injections of rapid or short duration insulin to modulate blood glucose throughout the day are improving A1C for T1D patients. Studies have shown that intensive treatment with 3 or 4 injections a day provide the best blood sugar control and reduce or delay eye, kidney, and nerve damage caused by diabetes. Intensive insulin therapy allows better insulin coverage, reducing the risk of nighttime hypoglycemia and morning hyperglycemia, the latter due to the normal release of cortisol and growth hormone early in the day.

Instant Feedback:

Intensive insulin therapy involves injecting insulin once in the morning and at bedtime.
True
 False

Adjustment situations

Insulin regimens for T1D or T2D patients incorporate the individual's insulin deficiency, insulin resistance, comorbidities, lifestyle, and socio-economic factors. Insulin requirements for persons with T1D, who are within 20% of ideal body weight, range between one-half and 1 unit per kilogram of body weight per day. During illness, insulin requirements rise for persons with either T1D or T2D, sometimes to several hundred units per day, depending on the extent of insulin deficiency and resistance. Insulin requirements for pregnant women with pre-existing diabetes gradually increase during the second and third trimesters of pregnancy.

Instant Feedback:

Insulin requirements for pregnant women with pre-existing diabetes gradually decrease during the 2nd and 3rd trimesters of pregnancy.
True
 False

References

Kennedy, M. N., Bedrich, M., Gray, l., Kroon, L. & Demetsky, M. (2020). Diabetes Education Online. The University of California, San Francisco/UCSF Medical Center Accessed online 12/06/20 http://dtc.ucsf.edu/types-of-diabetes/type1/understanding-type-1-diabetes/basic-facts/treatment-goals/

Ripsin, M; Kang, H; et al. (2009). Management of Blood Glucose in Type 2 Diabetes Mellitus. American Family Physician. 79(1), 29-36.

© RnCeus.com