Diabetes, Insulin Management

Scenario 1:
A 65-year-old male with DM2 routinely has fasting blood glucose levels in the 80–100 mg/dL range and her hemoglobin A1c level is 7.8%. She has been diligently monitoring her blood glucose levels and all are acceptable with the exception of elevated bedtime readings. She currently is on insulin glargine (Lantus), 18 U at night. What should you do? Adding rapid-acting insulin at dinner.
This patient continues to have an elevated hemoglobin A1c and bedtime hyperglycemia. The addition of a rapid-acting insulin at dinner would be the next step in management. For patients exhibiting blood glucose elevations before dinner, the addition of rapid-acting insulin at lunch is preferred. For patients with elevations before lunch, rapid-acting insulin with breakfast would most likely improve glucose control.

Scenario 2:
Your type I DM patient takes a basal insulin and many bolus insulin injections daily. As you review her glucose log, you notice a trend of an elevated pre-breakfast glucose level and dinner time levels that average 90mg/dL. Her 3 am glucose is 60mg/dl.
Q: What change should you make to her regimen?  Decrease the evening dose of basal insulin.

The Somogyi Effect vs. Dawn Phenomenon?

“The early morning hyperglycemia is due to the Somogyi effect. This is a rebound hyperglycemia (pre-breakfast) that is a response to hypoglycemia (nighttime/early morning). It is thought to occur when a patient becomes hypoglycemic (due to too much nighttime basal insulin) which causes an adrenergic outpouring (epinephrine, growth hormone, cortisol, and glucagon) that activates gluconeogenesis and glycogenolysis that ultimately leads to a reactive hyperglycemia. Treatment will be to decrease the evening dose of long-acting insulin or give bedtime snacks.

“Another cause of pre-breakfast hyperglycemia is the Dawn phenomenon. The Dawn phenomenon is secondary to the surge of growth hormone which antagonizes insulin action leading to elevated pre-breakfast glucose levels. By checking the blood glucose level at 3 am, one can differentiate between the Somogyi effect (low glucose at 3 am) and Dawn phenomenon (high glucose level). Treatment for the Dawn phenomenon is to increase the evening dose of basal insulin.

“Changing the evening dose of bolus insulin will have minimal effect on pre-breakfast insulin levels due to the short acting nature of the insulin.”