What is the next step in managing a patient with normal premeal blood glucose levels?

Next Step: Check Postprandial (Post-Meal) Blood Glucose

When premeal glucose levels are consistently normal (80-130 mg/dL), the next critical step is to measure postprandial blood glucose 1-2 hours after meals to identify hidden glycemic excursions that may be preventing achievement of A1C goals. 1

Why Postprandial Monitoring is Essential

• Normal fasting glucose does not guarantee adequate overall glycemic control. Only 64% of patients achieving fasting glucose targets <100 mg/dL actually achieve an A1C target <7%, whereas 94% of patients achieving postprandial targets <140 mg/dL do. 2

• Postprandial hyperglycemia accounts for approximately 80% of A1C when A1C is <6.2%, making it the dominant contributor to overall glycemic control in patients with near-target A1C levels. 2

• Postprandial glucose decreases account for nearly twice as much of A1C reduction as fasting glucose decreases in intervention studies. 2

Specific Monitoring Protocol

Timing: Measure blood glucose exactly 1-2 hours after the beginning of the meal, which captures peak glucose levels in patients with diabetes. 3, 1

Target: Peak postprandial capillary plasma glucose should be <180 mg/dL for most nonpregnant adults with diabetes. 3, 1

Frequency: If A1C goals are not being met despite normal premeal values, postprandial monitoring should be performed regularly after meals until the pattern is understood and corrected. 3, 1

Clinical Rationale

• The ADA explicitly recommends targeting postprandial glucose when A1C goals are not met despite reaching preprandial glucose goals. 3

• Elevated postprandial glucose values have been associated with increased cardiovascular risk independent of fasting plasma glucose in epidemiological studies. 3

• Control of fasting hyperglycemia alone is necessary but usually insufficient for achieving A1C goals <7%. Control of postprandial hyperglycemia is essential. 2

Common Pitfall to Avoid

Do not rely solely on fasting glucose or A1C to assess glycemic control, as postprandial excursions can be missed. 1 Many patients appear well-controlled based on premeal values but have significant postprandial hyperglycemia driving their A1C above target. 2

If Postprandial Values Are Also Normal

If both premeal (80-130 mg/dL) and postprandial (<180 mg/dL) glucose values are consistently at target but A1C remains elevated, consider:

• Verifying glucose meter accuracy and proper testing technique 3
• Checking for conditions affecting A1C interpretation (hemoglobinopathies, anemia, etc.)
• Increasing monitoring frequency to capture missed hyperglycemic episodes, particularly overnight or between standard testing times 1