Question

Identify the correct statements relating to blood glucose .
A. The principle fuel for the brain is glucose .
B. Untreated diabetes mellitus may lead to acidosis.
C. The average glucose concentration of an individual can be assessed by estimating its effect on hemoglobin .
D. Untreated diabetes mellitus may lead to ketosis.
Choose the correct answer from the options given below:

• A. A, B, C and D
• B. A, B and C only
• C. A , C and D only
• D. A and C only

Hint:

HbA1c is a gold standard diagnostic marker for monitoring long-term glucose control in diabetic patients, reflecting glycemic levels over a 90-day window.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Glucose is a critical carbohydrate metabolite in mammalian physiology.
Its concentration in the bloodstream is tightly regulated by hormones like insulin and glucagon.
Dysregulation of this pathway, as seen in diabetes mellitus, leads to systemic metabolic disturbances.

Step 2: Detailed Explanation:
Let us analyze each statement individually:
Statement A: The brain has a high metabolic demand and relies almost exclusively on glucose as its primary fuel source under normal physiological conditions, because fatty acids cannot cross the blood-brain barrier.
Statement B & D: In untreated diabetes mellitus, the lack of effective insulin action prevents cells from taking up glucose. In response, the body increases lipolysis, releasing fatty acids that are converted by the liver into ketone bodies (acetoacetate and \(\beta\)-hydroxybutyrate).
The accumulation of these acidic ketone bodies leads to ketosis (elevated ketone levels) and ketoacidosis (a decrease in blood pH, causing metabolic acidosis).
Statement C: High levels of blood glucose lead to non-enzymatic glycation of hemoglobin in red blood cells.
Estimating the fraction of glycated hemoglobin (HbA1c) provides an assessment of the average blood glucose concentration over the preceding 2 to 3 months (the lifespan of an erythrocyte).
Since statements A, B, C, and D are all scientifically accurate, Option A is the correct choice.

Step 3: Final Answer:
All four statements (A, B, C, and D) are correct.