Postprandial Glucose

Function

Postprandial glucose measures the level of sugar in the blood specifically after a meal (usually 2 hours after). This test assesses how well the body manages the influx of glucose by secreting insulin and utilizing sugar in the tissues.

Why it is Ordered

While fasting glucose is standard, postprandial glucose is often a more sensitive marker for early-stage Type 2 Diabetes and impaired glucose tolerance. It is also used to monitor the effectiveness of mealtime insulin or oral hypoglycemic agents in patients already diagnosed with diabetes.

Associated Conditions

• Prediabetes: Characterized by glucose levels between 140 and 199 mg/dL after 2 hours.
• Diabetes Mellitus: Confirmed by levels ≥ 200 mg/dL.
• Reactive Hypoglycemia: Low blood sugar levels following a meal, often seen in early insulin resistance or after gastric bypass surgery.
• Gestational Diabetes: Postprandial monitoring is the gold standard for managing glucose in pregnancy.

Importance of Timing

The "2-hour" mark is critical because, in healthy individuals, insulin should have returned blood glucose levels to near-normal by this time. Persistent elevation indicates 'postprandial spikes,' which are highly correlated with cardiovascular risk and oxidative stress.