How often should blood sugar be assessed in a patient with an Hemoglobin A1c (HbA1c) level over 7%?

A1c Testing Frequency for Patients with A1c Over 7%

For patients with A1c levels over 7%, the A1c test should be performed quarterly (every 3 months) as these patients are not meeting glycemic goals. 1

Testing Frequency Based on Glycemic Control

• Perform A1c testing quarterly (every 3 months) for patients whose A1c is over 7% as they are not meeting treatment goals 1
• Perform A1c testing at least twice yearly (every 6 months) only for patients who are meeting treatment goals and have stable glycemic control 1
• More frequent testing may be needed for unstable or highly intensively managed patients, such as pregnant women with type 1 diabetes 1, 2

Rationale for Quarterly Testing

• A1c reflects average glycemia over approximately 3 months and has strong predictive value for diabetes complications 1
• Quarterly testing allows for timely evaluation of therapy effectiveness and appropriate adjustments to prevent long-term complications 1
• Point-of-care testing for A1c provides the opportunity for more timely treatment changes when needed 1, 2

Complementary Blood Glucose Monitoring

• A1c testing should be combined with self-monitoring of blood glucose (SMBG) for optimal management, especially for patients with A1c over target 1
• For patients with A1c over 7%, more frequent SMBG may be needed to identify patterns of hyperglycemia and guide therapy adjustments 1
• Continuous glucose monitoring (CGM) may provide additional benefit for patients with elevated A1c, particularly those on intensive insulin regimens 1

Clinical Considerations and Pitfalls

• A1c does not provide information about glycemic variability or hypoglycemia, which are important aspects of diabetes management 1, 2
• Conditions affecting red blood cell turnover (hemolysis, blood loss) and hemoglobin variants can affect A1c results and must be considered when results don't correlate with blood glucose levels 1, 2
• When A1c and self-monitored blood glucose values appear discrepant, consider hemoglobinopathy, altered red blood cell turnover, or inadequate SMBG testing schedule 1, 2

Interpreting A1c Results

• An A1c over 7% correlates with an estimated average glucose of approximately 154 mg/dL or higher 1, 3
• For patients with A1c between 7.0-7.49%, average fasting blood glucose is approximately 152 mg/dL (143-162 mg/dL) 3
• Post-meal blood glucose values for patients with A1c between 7.0-7.49% average around 152 mg/dL (147-157 mg/dL) 3

Treatment Considerations

• Use quarterly A1c results to guide therapy adjustments aimed at achieving individualized glycemic targets 1
• Point-of-care A1c testing can facilitate more immediate treatment changes during the patient visit 1, 2
• The American Diabetes Association generally recommends an A1c target of less than 7% for many adults with diabetes to reduce microvascular complications 1, 4