What is the fasting blood sugar (FBS) cut-off for diagnosing diabetes mellitus?

Appeared in: NORCET 10 Mains

Explanation

A fasting blood sugar (FBS) or fasting plasma glucose (FPG) level of 126 mg/dL or higher is a primary diagnostic criterion for diabetes mellitus.
This standard is recommended by the American Diabetes Association (ADA) and the World Health Organization (WHO).
A diagnosis is confirmed if this level is met on two separate tests, unless the patient presents with clear symptoms of hyperglycemia and a random glucose of 200 mg/dL or higher.

Option B: This value is a threshold for diagnosing prediabetes (Impaired Glucose Tolerance), not diabetes, and it applies to the 2-hour Oral Glucose Tolerance Test (OGTT), not a fasting test.
Option C: This is the diagnostic cut-off for diabetes, but for a 2-hour OGTT or a random plasma glucose test, not a fasting test.
Option D: This value is not a primary diagnostic criterion for diabetes. It represents the typical renal threshold for glucose.

Clinical Relevance

Nursing practice connection: Knowing Diagnostic criteria for Diabetes Mellitus using Fasting Blood Sugar (FBS) helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Accurate diagnosis based on established criteria is crucial for initiating timely management, including lifestyle changes and medication, to prevent long-term complications like nephropathy, retinopathy, and cardiovascular disease.
Nurses play a key role in patient education, explaining the meaning of test results, the importance of follow-up testing, and the initial steps for managing prediabetes or diabetes.
What if? If a patient's FBS is 115 mg/dL, the nurse should identify this as prediabetes (Impaired Fasting Glucose). The priority action is to educate the patient on lifestyle modifications (diet, exercise, weight loss) to delay or prevent the progression to type 2 diabetes.

How to Approach the Question

First, identify the specific test mentioned in the question: 'Fasting Blood Sugar (FBS)'.
Second, recall the established numerical cut-offs for diagnosing diabetes mellitus.
Third, differentiate the FBS criterion from criteria related to other tests like the Oral Glucose Tolerance Test (OGTT) or random glucose measurements.
Fourth, compare the options to the recalled FBS cut-off. The value of 126 mg/dL is the specific threshold for an FBS test.
Finally, select the option that matches the correct diagnostic value for a fasting test.

Concept Tested & Keywords

Concept Tested: Diagnostic criteria for Diabetes Mellitus using Fasting Blood Sugar (FBS)
Stem keywords: fasting blood sugar, FBS, cut-off, diagnosing, diabetes mellitus
Lead-in keywords: What is
Negative lead-in flag: false

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