MKSAP quiz: Meeting HbA1c goals in type 2 diabetes

This month's quiz asks readers to treat a patient with type 2 diabetes who is taking insulin detemir, prandial insulin lispro, and metformin and wishes to reduce his HbA1c level to below 7%.

A 45-year-old man is seen in routine follow-up for his type 2 diabetes mellitus. He was diagnosed 5 years ago, and he does not have any diabetes-related complications. His current treatment includes insulin detemir, prandial insulin lispro, and metformin. His HbA1c level has decreased to 7.4%. His fasting and preprandial blood glucose measurements range from 110 to 130 mg/dL (6.1-7.2 mmol/L). He has had no hypoglycemia. Medical history is significant for obesity. He wishes to reduce his HbA1c level to below 7%, but he is reluctant to add another injectable medication to his regimen. Medications are insulin detemir, insulin lispro, and metformin.

On physical examination, vital signs are normal. BMI is 33. The remainder of the physical examination is unremarkable.

Which of the following is the most appropriate management of this patient's diabetes?

A. Add liraglutide
B. Continue current regimen
C. Increase insulin detemir dose
D. Measure postprandial blood glucose level

MKSAP Answer and Critique

The correct answer is D. Measure postprandial blood glucose level. This item is available to MKSAP 18 subscribers as item 63 in the Endocrinology and Metabolism section. More information about MKSAP 18 is available online.

Measuring postprandial blood glucose level is the most appropriate management of this patient's diabetes. This patient is healthy with few comorbidities. His preprandial blood glucose target is 80 to 130 mg/dL (4.4-7.2 mmol/L). Despite meeting his preprandial glycemic targets, his HbA1c level remains above his goal of less than 7%. Postprandial hyperglycemia has a greater effect on HbA1c when it is near 7%. Measuring postprandial blood glucose levels in this patient may identify undetected hyperglycemia that could be treated with an increase in his prandial insulin lispro dose.

Liraglutide is an injectable glucagon-like peptide-1 (GLP-1) receptor agonist with several mechanisms of action: slows gastric emptying, glucose-dependent increase in insulin secretion, and glucose-dependent suppression of glucagon secretion. Although liraglutide has the potential to aid with weight loss in this patient with obesity and to improve his HbA1c to goal, adding another injectable agent to the regimen of a patient who is reluctant to do this does not take into consideration patient preferences. In addition, liraglutide has not been approved by the FDA for combination use with prandial insulin.

Continuing his current regimen will not allow him to achieve his target HbA1c goal. The American Diabetes Association recommends a HbA1c goal of less than 6.5% to 7% for healthy persons with type 2 diabetes mellitus with few comorbidities to decrease the incidence of diabetes-related complications in the future. ACP recommends a target HbA1c level between 7% and 8% for most patients with type 2 diabetes. ACP notes that more stringent targets may be appropriate for patients who have a long life expectancy (>15 years) and are interested in more intensive glycemic control despite the risk for harms.

The patient has reached the recommended preprandial glycemic goal of 80 to 130 mg/dL (4.4-7.2 mmol/L). Increasing his insulin detemir dose may increase his risk of developing hypoglycemia and would not adequately treat postprandial hyperglycemia that may be contributing to the elevated HbA1c.

Key Point

  • Measuring postprandial blood glucose levels may identify undetected hyperglycemia when preprandial blood glucose values are at target goal, but the HbA1c is above goal.