A 60-year-old man comes to the office for follow-up of type 2 diabetes mellitus. His current treatment regimen includes metformin and a once-daily injection of a long-acting subcutaneous insulin. The patient is adherent with the treatment and has a healthy lifestyle. Review of his home glucose measurements shows that his postprandial glucose levels are frequently elevated; however, fasting levels are normal. He has no other medical conditions and does not use tobacco, alcohol, or illicit drugs. Vital signs are within normal limits. Physical examination shows no abnormalities. Laboratory testing reveals hemoglobin A1c is 8.3%. Additional insulin therapy 3 times a day before each meal is planned to improve glycemic control. Which of the following types of insulin would be most appropriate for the additional therapy?

Question

A 60-year-old man comes to the office for follow-up of type 2 diabetes mellitus.  His current treatment regimen includes metformin and a once-daily injection of a long-acting subcutaneous insulin.  The patient is adherent with the treatment and has a healthy lifestyle.  Review of his home glucose measurements shows that his postprandial glucose levels are frequently elevated; however, fasting levels are normal.  He has no other medical conditions and does not use tobacco, alcohol, or illicit drugs.  Vital signs are within normal limits.  Physical examination shows no abnormalities.  Laboratory testing reveals hemoglobin A1c is 8.3%.  Additional insulin therapy 3 times a day before each meal is planned to improve glycemic control.  Which of the following types of insulin would be most appropriate for the additional therapy?

Quizplus · Accepted Answer

11ec160b_3baf_7b57_9249_d1ba652e62ae_MD0001_00 The beta cells of the pancreas produce insulin continuously at a low level. After meals, insulin secretion increases briefly to control the postprandial rise in blood glucose. Commercial insulin analogs are formulated with different pharmacokinetic properties that can be used to replicate physiologic insulin secretion: Long-acting insulins have an extended duration of action and little or no peak in activity. They are typically given once daily to mimic basal insulin secretion. Rapid-acting insulins are quickly taken up from the injection site and then rapidly cleared. They are given at mealtimes to replicate the normal postprandial increase in insulin secretion. This patient has normal fasting glucose levels, suggesting that his long-acting basal insulin therapy is appropriate. However, his postprandial glucose readings are elevated. Adding a rapid-acting insulin analog (eg, aspart, lispro, glulisine) with meals would reduce postprandial glucose and improve overall glycemic control. Because the rapid-acting insulins are cleared quickly, they have minimal residual effect on fasting glucose levels. Regular insulin also can be given at mealtimes but forms dimers and hexamers, which cause a slight delay in uptake from the injection site and prolongation of effect. (Choices B, C, and D) Insulin degludec has addition of a hexadecanedioic acid residue, which causes polymer formation at the injection site and slowed uptake. Detemir has a fatty acid side chain added to lysine B29 of the insulin molecule, which causes it to bind circulating albumin and slowly dissociate. Glargine has a pH of 4 and forms a microprecipitate at the injection site, resulting in delayed absorption. These analogs all have a long duration of action with minimal peak and are used for basal insulin therapy. As such, they would be poor choices for controlling postprandial glucose. (Choice E) NPH is a crystalline suspension of insulin with protamine and zinc, which delays absorption from the injection site. NPH is an intermediate-acting insulin that is typically given twice daily; although it has a noticeable peak effect, it is used primarily as basal insulin. Educational objective: Long-acting insulin analogs (eg, degludec, detemir, glargine) have an extended duration of action without a noticeable peak in activity and are typically given once daily to mimic basal insulin secretion. Rapid-acting insulins (eg, aspart, lispro, glulisine) are quickly absorbed from the injection site and are given at mealtimes to replicate postprandial insulin secretion. __________ References: Insulin analogs: glimpse on contemporary facts and future prospective. (http://www.ncbi.nlm.nih.gov/pubmed/30639280)

A 60-Year-Old Man Comes to the Office for Follow-Up of Type