How often should I recheck my Hemoglobin A1c (HbA1c) level if it is 5.8?

A1C Rechecking for a Value of 5.8%

For an A1C of 5.8%, which falls in the prediabetes range, you should recheck the A1C in 12 months if the patient is stable and meeting preventive care goals. 1

Understanding the A1C Value of 5.8%

• An A1C of 5.8% places the patient in the prediabetes category (5.7-6.4% per American Diabetes Association criteria), indicating significantly elevated risk for developing diabetes 2
• Research demonstrates that A1C values between 5.5-6.0% are associated with a 9-25% incidence of diabetes over 5 years, representing a moderately increased relative risk 2
• This level does not meet diagnostic criteria for diabetes (≥6.5%) but warrants monitoring and preventive interventions 1

Recommended Testing Frequency

For stable patients with prediabetes:

• The American Diabetes Association recommends A1C testing at least twice yearly for patients meeting treatment goals with stable glycemic control 1
• For persons with stable A1C over several years, measurement every 12 months may be appropriate 1
• Annual testing (every 12 months) is reasonable for a patient with prediabetes who is stable and engaged in preventive measures 1

More frequent testing (every 3-6 months) is indicated if:

• The patient is not meeting preventive care goals or lifestyle modification targets 1
• There are recent changes in health status, medications, or weight 1
• The patient has additional risk factors requiring closer monitoring 1
• The A1C is trending upward on serial measurements 1

Clinical Context and Risk Stratification

• The A1C of 5.8% represents a point where retinopathy prevalence begins to increase sharply (inflection point at A1C ≥5.5%), though absolute risk remains relatively low 3
• This value indicates the patient should receive counseling about diabetes prevention, including lifestyle modifications (diet, exercise, weight loss if indicated) 2
• Consider more frequent monitoring (every 6 months) if the patient has multiple diabetes risk factors, is not adherent to lifestyle modifications, or has other concerning metabolic parameters 1

Common Pitfalls to Avoid

• Do not wait longer than 12 months to recheck in a patient with prediabetes, as this represents a window of opportunity for prevention 2
• Do not check too frequently (e.g., every 3 months) in stable prediabetes without treatment changes, as A1C reflects 2-3 months of glycemia and more frequent testing adds no clinical value 1
• Consider factors that may affect A1C accuracy, such as hemolytic anemia, recent blood transfusion, hemoglobin variants, or conditions affecting red blood cell turnover, which could lead to misleading results 1
• Do not use point-of-care A1C devices for diagnosis or screening unless they are FDA-approved and performed at CLIA-certified laboratories with moderate complexity testing or higher 1