Why is the doctor waiting for the Hemoglobin A1C (HbA1C) test results before prescribing Ozempic (semaglutide)?

Why Doctors Require A1C Testing Before Prescribing Ozempic

Doctors require A1C testing before prescribing Ozempic (semaglutide) because it is the primary tool for assessing glycemic control, has strong predictive value for diabetes complications, and helps determine if patients meet the criteria for this medication. 1

Role of A1C Testing in Diabetes Management

• A1C testing reflects average glycemia over approximately 2-3 months and is the major tool for assessing glycemic control in patients with diabetes 1
• The test provides a quantitative and reliable measure of glycemia over an extended period that cannot be obtained from daily blood glucose testing alone 1
• A1C has strong predictive value for diabetes complications, making it essential for treatment decisions 1
• Point-of-care A1C testing allows for timely decisions on therapy changes during patient encounters 1, 2

Why A1C is Required Before Prescribing Ozempic

• Ozempic (semaglutide) is indicated for adults with type 2 diabetes mellitus to improve blood sugar along with diet and exercise 3

• A1C testing helps determine:

  • If the patient truly has type 2 diabetes that requires medication intervention 1, 2
  • The severity of hyperglycemia, which guides appropriate medication selection 1
  • A baseline measurement to evaluate treatment effectiveness in follow-up visits 1

• Clinical trials for Ozempic used A1C as the primary endpoint to demonstrate efficacy, with significant reductions observed in patients with elevated baseline A1C values 3, 4

A1C Target Values and Treatment Decisions

• The American Diabetes Association recommends an A1C goal of less than 7% for most nonpregnant adults with diabetes 1

• Table 6.1 shows the correlation between A1C levels and mean glucose levels:

  • A1C of 7% corresponds to mean glucose of 154 mg/dL
  • A1C of 8% corresponds to mean glucose of 183 mg/dL
  • A1C of 9% corresponds to mean glucose of 212 mg/dL 1

• Higher A1C values indicate more severe hyperglycemia and may influence the starting dose and titration schedule for Ozempic 3

Monitoring Protocol After Starting Ozempic

• A1C testing should be performed approximately every 3 months after starting Ozempic to determine if glycemic targets have been reached and maintained 1, 2
• Real-world studies show that patients on Ozempic 1.0 mg maintenance dose experienced mean A1C reductions of 1.2-1.4% 4
• Clinical trials demonstrated that significantly more patients achieved both ≥1.0% A1C reduction and ≥5.0% weight loss with semaglutide compared to other treatments 5

Limitations and Considerations for A1C Testing

• A1C is subject to limitations and may be affected by conditions that impact red blood cell turnover, such as:

  • Hemolytic and other anemias
  • Glucose-6-phosphate dehydrogenase deficiency
  • Recent blood transfusion
  • Use of drugs that stimulate erythropoiesis
  • End-stage kidney disease
  • Pregnancy 1, 6

• Hemoglobin variants must be considered, particularly when the A1C result does not correlate with the patient's self-monitoring blood glucose levels 1, 6

Common Pitfalls to Avoid

• Failing to establish a baseline A1C before starting treatment makes it difficult to assess medication effectiveness 1, 2
• Not considering factors that may affect A1C results can lead to inappropriate medication selection or dosing 1, 6
• Relying solely on A1C without considering blood glucose monitoring data may miss glycemic variability or hypoglycemia risk, especially in patients prone to these issues 1