Which of the following is a common cause of metabolic acidosis?

• A. Chronic liver disease
• B. Diabetic ketoacidosis
• C. Heart failure
• D. Hyperaldosteronism

Answer: (B)

Metabolic acidosis is characterized by a decrease in the blood pH due to an accumulation of acid or loss of bicarbonate. Diabetic ketoacidosis is a well-known cause of metabolic acidosis that occurs primarily in patients with uncontrolled diabetes mellitus. In this condition, a lack of insulin leads to increased production of ketone bodies, which are acidic byproducts of fat metabolism. The excessive accumulation of these ketones leads to an increased acid load in the blood, thereby lowering the pH and resulting in metabolic acidosis.

In contrast, chronic liver disease, heart failure, and hyperaldosteronism can influence acid-base balance but are not direct causes of metabolic acidosis. For instance, chronic liver disease can lead to changes in metabolic processes but is more commonly associated with an alkalosis or mixed acid-base disorders. Heart failure can affect perfusion and oxygen delivery, potentially leading to lactic acidosis, but it does not intrinsically cause metabolic acidosis by itself. Hyperaldosteronism typically results in metabolic alkalosis due to bicarbonate retention and hydrogen ion excretion rather than a direct increase in acidity. Thus, diabetic ketoacidosis stands out as the most appropriate and direct cause of metabolic acidosis.