The cause of type 1 DM acidosis?

Appeared in: NIMHANS Nursing Officer - 2021

Explanation

In Type 1 Diabetes Mellitus, an absolute deficiency of insulin prevents glucose from being used as an energy source.
The body compensates by breaking down fat (lipolysis), which produces acidic byproducts called ketone bodies (e.g., acetoacetate, β-hydroxybutyrate).
These ketones accumulate in the blood, overwhelming the body's buffering systems and causing the blood pH to drop, resulting in metabolic acidosis.
This entire process is known as Diabetic Ketoacidosis (DKA).

Option B: Acidosis is the resulting condition or effect, not the cause. The question asks for what causes the acidosis.
Option C: Alkalosis is a condition where the blood pH is too high (basic), which is the opposite of what occurs in DKA.
Option D: This option is incorrect because a valid cause is listed among the choices.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of Diabetic Ketoacidosis (DKA) as background academic context rather than a clinical decision trigger.
Recognizing the cause of DKA is critical for nurses to understand the rationale behind emergency treatments like insulin and fluid administration.
The characteristic 'fruity' or acetone-like smell on a patient's breath is a key sign of ketosis and should prompt immediate investigation for DKA.
Patient education is a vital nursing role, including teaching patients with Type 1 DM about sick day rules and the importance of continued insulin therapy even with poor oral intake to prevent DKA.

How to Approach the Question

First, identify the core of the question: it asks for the 'cause' of acidosis specifically in the context of 'Type 1 DM'.
Analyze the relationship between the options and the condition. 'Acidosis' is the condition itself, so it cannot be its own cause. This eliminates option B.
Recall the pathophysiology of Type 1 DM. The hallmark is insulin deficiency.
Consider the metabolic consequences of insulin deficiency: the body cannot use glucose and switches to fat metabolism.
Connect fat metabolism to its byproducts. The breakdown of fats produces ketone bodies.
Recall the chemical nature of ketone bodies: they are acidic. Their accumulation leads to a drop in blood pH, which is the definition of acidosis.

Concept Tested & Keywords

Q84NitOOkLwNZwD6urYqa4

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 1 (pp 26-370 of 370) p. 199-201

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 561-563

E6 Medicine Davidson Principles Practice 24e p. 385-387

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Attempt every question from this paper in a timed mock, then review the full solution for each one.