Diabetes Mellitus:- Part 3 – Glucose after 2 hours of meal (postprandial glucose level)

Glucose after 2 hours (Postprandial glucose)

What Sample for blood glucose is required?

1. The test is done on the serum of patients or oxalate blood.
   • When the test is done on the serum, the serum should be separated within 30 minutes of collection.
2. The serum can be stored at 25 °C for 8 hours and at 4°C for 72 hours.
3. Oxalated blood can also be used. Preservative sodium fluoride may be added.
   • The plasma can be stored at 25 °C for 24 hours (with preservative sodium fluoride).

What Precautions for blood glucose are necessary?

1. In the case of fluoride as a preservative, a 9 mg/dL decrease is seen during the first 2 hours.
2. The whole blood glucose level is approximately 90% of the plasma glucose level.

Pathophysiology of glucose metabolism

How will you discuss the pathophysiology of glucose metabolism?

1. Carbohydrate metabolism and interaction between carbohydrates, fats, and proteins. This interaction is important for our body to control glucose levels.

How will you define 2-hour glucose level (postprandial glucose)?

1. Blood glucose is measured postprandial (2 hours after the test meal).
2. It will increase glucose tolerance in the body 2 hours after the meal.
3. A meal acts as a glucose challenge for the body’s metabolism.
4. Insulin is secreted in response to increased glucose levels due to food intake.
5. Blood glucose levels will return to normal within 2 hours through the insulin secretion.
   1. In diabetic patients, glucose levels will remain elevated.

How will you interpret postprandial or 2-hour glucose?

1. Postprandial glucose level is a screening test for Diabetes Mellitus.
2. If the glucose level is >140 mg/dL and <200 mg/dL, then a GTT (glucose tolerance test) is advised.
3. If the level after 2 hours is greater than 200 mg/dL, diabetes mellitus is confirmed.
4. Advise HbA1c for further evaluation.

What is a 2-hour (postprandial) normal glucose level?

Source 1

• <120 mg/dL
  • To convert into SI unit x 0.0555 = mmol/L

2-hour glucose (postprandial)level:

1. Normal = <140 mg/dL.
2. Impaired glucose tolerance (IGT) = 140 to 199 mg/dL
3. Diabetes mellitus = ≥200 mg/dL

Another source 2

What is the latest criterion for Diabetes Mellitus?

1. The level of 200 mg/dl or
   1. Above 200 mg/dl after 75 grams of glucose overload or
2. Two casual glucose readings of 200 mg/dL or above are considered diabetic.
   • This test is not recommended due to the numerous factors that can influence the result.

• For more details on Glucose, please refer to the fasting glucose level.

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