Diabetes Mellitus:- Part 3 – Glucose after 2 hours of meal (postprandial glucose level)
Glucose after 2 hours (Postprandial glucose)
- The test is done on the serum of patients or oxalate blood.
- When the test is done on serum, the serum should be separated within 30 minutes of collection.
- The serum can be stored at 25° C for 8 hours and 72 hours at 4 °C.
- Oxalate 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).
- In the case of fluoride as a preservative, a decrease of 9 mg/dL is seen during the first 2 hours.
- The whole blood glucose level is 90% of the plasma glucose.
Pathophysiology of glucose
- Carbohydrate metabolism and interaction between carbohydrates, fats, and proteins. This interaction is important for our body to control glucose levels.
Definition of 2 hours of glucose level (postprandial glucose) :
- It will give you the body’s glucose tolerance after 2 hours of a meal.
- Meal acts as a glucose challenge for body metabolism.
- Insulin is secreted in response to increased glucose levels due to food intake.
- Blood glucose will be normal within 2 hours.
- In diabetic patients, glucose levels will remain elevated.
Interpretation of postprandial or 2 hours of glucose:
- Postprandial glucose level is a screening test for DM.
- If glucose level is >140 mg/dL and <200 mg/dL, then GTT (glucose tolerance test) is advised.
- If level after 2 hours = >200 mg/dL, diabetes mellitus is confirmed.
- Advise HbA1c for further evaluation.
Normal 2 hours (postprandial) glucose level:
- <120 mg/dL
- To convert into SI unit x 0.0555 = mmol/L
- 0 to 50 years = < 140 mg/dl (<7.7 mmol/L)
- And some believes <120 mg/dl ( < 6.66 mmol/L).
- For people age 50 and younger = < 140 mg/dL (7.8 mmol/L).
- For people ages 50 – 60 = <150 mg/dL (8.3 mmol/L).
- For people aged 60 and older = <160 mg/dL (8.9 mmol/L)
2 hours glucose (postprandial)level:
- Normal = <140 mg/dL.
- Impaired glucose tolerance (IGT) = 140 to 199 mg/dL
- Diabetes mellitus = ≥200 mg/dL
The latest criteria for Diabetes Mellitus:
- The level of 200 mg/dl or
- Above 200 mg/dl after 75 grams of glucose overload or
- Two casual glucose readings 200 mg/dl or above are labeled as Diabetic patients.
- This test is not recommended because of the many factors influencing the result.
|Diagnosis||Fasting glucose level||Random glucose level||2-hour glucose level (in OGTT)||HbA1c|
|Prediabetics||100 to 125 mg/dL||140 to 199 mg/dL||140 to 199 mg/dL||5.7 to 6.4%|
|Diabetes mellitus||> 126 mg/dL||>200 mg/dL||>200 mg/dL||>6.5%|
- Please, for more details on Glucose, see in Glucose fasting level.