Mr. Murali has 126 mg/dl of fasting plasma glucose. His venous plasma glucose 2h after ingestion of 75g oral glucose load is 149 mg/dl. This patient comes under which stage of WHO diagnostic criteria of diabetes & intermediate hyperglycemia?
First, I need to recall the WHO diagnostic criteria for diabetes and intermediate hyperglycemia. The core concept here is understanding the thresholds for normal, impaired glucose tolerance, and diabetes. The WHO has specific cutoffs for fasting and postprandial glucose levels.
Fasting glucose is a key point. The normal fasting level is below 100 mg/dl. If it's between 100-125, that's impaired fasting glucose. If it's 126 mg/dl or higher, that's diabetes. For the 2-hour oral glucose tolerance test (OGTT), normal is less than 140 mg/dl. If it's between 140-199, it's impaired glucose tolerance. 200 mg/dl or higher is diabetes.
Looking at the patient's values: fasting is 126, which is in the diabetes range. The 2-hour is 149, which is between 140-199. But wait, if the fasting is already in the diabetic range, does the 2-hour matter? The WHO criteria state that a diagnosis of diabetes can be made if either the fasting or the 2-hour value meets the criteria. So even though the 2-hour is in the impaired glucose tolerance range, the fasting is already diagnostic for diabetes.
Now, the options aren't provided, but the correct answer should be diabetes. The other options would be impaired glucose tolerance or normal. The user's answer was correct as diabetes. So the explanation should clarify that even though the 2-hour is in the impaired range, the fasting is sufficient for a diabetes diagnosis.
I need to make sure to explain why the fasting value is the key here. Also, mention that the 2-hour value alone would be impaired glucose tolerance, but since the fasting is higher, the diagnosis is diabetes. That's a common pitfall in these questions—students might focus on the 2-hour value and miss the fasting one.
The clinical pearl here is to remember that either the fasting or the 2-hour OGTT can be used to diagnose diabetes. Also, the thresholds are strict: 126 for fasting and 200 for 2-hour. But in this case, the fasting is over 126, so it's diabetes regardless of the 2-hour.
**Core Concept**
The World Health Organization (WHO) classifies diabetes mellitus using specific thresholds for fasting plasma glucose (FPG) and 2-hour post-glucose oral glucose tolerance test (OGTT). A diagnosis of diabetes requires **FPG ≥ 126 mg/dL** or **2-hour glucose ≥ 200 mg/dL**. Intermediate hyperglycemia (e.g., impaired fasting glucose or impaired glucose tolerance) occurs if values fall between normal and diabetic thresholds.
**Why the Correct Answer is Right**
Mr. Murali’s fasting plasma glucose of **126 mg/dL** meets the WHO criterion for diabetes mellitus (≥126 mg/dL). While his 2-hour