Ketone bodies are found in urine of patients with uncontrolled diabetes due to:

AIIMS Nagpur NO- 2020

Biochemistry & Nutrition

Hard

Appeared in: AIIMS Nagpur NO- 2020

Explanation

In uncontrolled diabetes, insulin deficiency or resistance prevents cells from utilizing glucose for energy, creating a state of cellular starvation despite high blood sugar.
To compensate, the body dramatically increases the breakdown of fat stores (lipolysis) into free fatty acids.
The liver metabolizes these fatty acids through a process called ketogenesis, which produces ketone bodies (acetoacetate, β-hydroxybutyrate, and acetone) as byproducts.
When ketone production exceeds the body's ability to use them for energy, they accumulate in the blood (ketonemia) and are excreted in the urine (ketonuria).

Option A: The primary metabolic byproduct of protein catabolism is urea, not ketone bodies. While some amino acids are ketogenic, fat is the main source of ketones in diabetic ketoacidosis.
Option C: Impaired kidney function is a potential consequence of the dehydration and acidosis associated with diabetic ketoacidosis (DKA), not the cause of ketone production. Ketones are produced in the liver.
Option D: Glucose does not decompose into ketones. The core problem is the body's inability to metabolize glucose, which triggers the switch to fat metabolism. High blood sugar is the problem, not the source of ketones.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of ketonuria in diabetes mellitus as background academic context rather than a clinical decision trigger.
Urine ketone testing is a critical nursing intervention for patients with Type 1 diabetes, especially during illness, stress, or when blood glucose is consistently high (e.g., greater than 250 mg/dL).
The presence of moderate to large ketones in the urine is a red flag for impending or existing Diabetic Ketoacidosis (DKA), a life-threatening medical emergency requiring immediate intervention with insulin and fluids.
Patient education should emphasize when and how to test for ketones and to seek medical help promptly if ketones are present, as this indicates a severe lack of insulin.

How to Approach the Question

First, identify the core clinical condition presented: 'uncontrolled diabetes'. This immediately signals a problem with insulin and glucose metabolism.
Analyze the question's core 'ask': It wants the reason ('due to') for the presence of 'ketone bodies in urine'.
Recall the primary function of insulin: it acts like a key to let glucose into cells for energy.
Deduce the consequence of 'uncontrolled diabetes': without effective insulin, glucose stays in the blood, and cells starve.
Consider the body's backup fuel plan. When glucose is unavailable, the body turns to its fat reserves.
Connect this backup plan to the question's keyword. The breakdown of fat (fat metabolism) produces ketone bodies as a byproduct. This directly links the cause (fat breakdown) to the effect (ketones).

Concept Tested & Keywords

Q83ZupsQvY09zHXw3zvZRQ

E6 Biochemistry U Satyanarayana— Part 1 (pp 26-420 of 840) p. 287-289

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 1 (pp 26-370 of 370) p. 226-228

E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 1105-1107