Guidelines for Glucose Monitoring in Patients with HbA1C Over 7%
For patients with HbA1C levels over 7%, monitoring should include routine HbA1C testing every 3 months until targets are achieved, then at least every 6 months, along with structured self-monitoring of blood glucose (SMBG) or continuous glucose monitoring (CGM) as appropriate for the patient's treatment regimen.
HbA1C Monitoring Frequency
- HbA1C should be measured routinely every 3 months until acceptable targets are achieved, then no less than every 6 months 1
- Quarterly measurements have been associated with significant reductions in HbA1C values 2
- For patients who have stable glycemic control, semiannual testing is appropriate; for those whose therapy has changed or who are not meeting glycemic goals, quarterly testing is recommended 1
Self-Monitoring of Blood Glucose (SMBG)
- SMBG is an integral component of effective therapy, particularly for patients taking insulin 1
- For patients with HbA1C over 7%, structured SMBG should be performed to evaluate individual response to therapy and assess whether glycemic targets are being safely achieved 1
- The frequency and timing of SMBG should be dictated by the patient's specific needs and goals 1
- Patients performing SMBG at least 1.5 times/day showed significant HbA1C improvement compared to those testing less frequently 3
Continuous Glucose Monitoring (CGM)
- CGM is rapidly improving diabetes management and provides additional metrics beyond HbA1C 1
- Time in range (TIR) is a useful metric that correlates well with HbA1C and should target >70% of readings between 70-180 mg/dL 1
- For patients with HbA1C over 7%, CGM can help identify patterns of hyperglycemia and hypoglycemia that may not be evident with SMBG alone 1
- Even intermittent short-term use of real-time CGM has shown efficacy in improving glycemic control in patients with uncontrolled type 2 diabetes 3
Target Blood Glucose Levels Based on HbA1C Goals
For patients with HbA1C target of 7.0-7.49%, the following average blood glucose values should be targeted 1, 4:
- Mean fasting glucose: 152 mg/dL
- Mean premeal glucose: 152 mg/dL
- Mean postmeal glucose: 176 mg/dL
- Mean bedtime glucose: 177 mg/dL
For patients with HbA1C target of 7.5-7.99%, the following average blood glucose values should be targeted 1, 4:
- Mean fasting glucose: 167 mg/dL
- Mean premeal glucose: 155 mg/dL
- Mean postmeal glucose: 189 mg/dL
- Mean bedtime glucose: 175 mg/dL
Individualized Target HbA1C Levels
A reasonable HbA1C goal for many nonpregnant adults is <7% without significant hypoglycemia 1
Less stringent HbA1C goals (such as <8%) may be appropriate for patients with 1, 5:
- History of severe hypoglycemia
- Limited life expectancy
- Advanced microvascular or macrovascular complications
- Extensive comorbid conditions
- Long-standing diabetes in whom the goal is difficult to achieve despite appropriate care
For older adults with good functional status, few comorbidities, and longer life expectancy (>10 years), a target HbA1C of approximately 7% is reasonable 5
For frail patients, those with limited life expectancy (<5 years), or with advanced complications, a target HbA1C of approximately 8% is appropriate 5
Avoiding Hypoglycemia
- Reaching current targets for time in hypoglycemia while simultaneously achieving HbA1C targets can be challenging 6
- CGM is associated with considerably less time in hypoglycemia than SMBG at a broad range of HbA1C levels 6
- For patients with HbA1C of 7.0%, mean time spent in hypoglycemia (<3.9 mmol/L or <70 mg/dL) is estimated to be 5.4% with CGM versus 9.2% with SMBG 6
- Avoid aggressive glycemic control in patients at high risk for hypoglycemia, particularly older adults 5
Common Pitfalls to Avoid
- Setting overly aggressive targets (HbA1C <6.5%) for patients with multiple comorbidities or at high risk for hypoglycemia 7
- Failing to adjust targets as patient circumstances change (e.g., development of comorbidities, aging) 7
- Overlooking the increased risk of hypoglycemia with intensive control, especially in patients with renal impairment 7
- Excessive focus on tight control may lead to treatment burden that outweighs benefits, particularly in older adults 5