Which statement about diabetic ketoacidosis is true?

• A. It typically presents with hyperosmolality
• B. It usually causes metabolic alkalosis
• C. It presents with an elevated anion gap and metabolic acidosis
• D. It never causes dehydration

Answer: (C)

Diabetic ketoacidosis causes an elevated anion gap metabolic acidosis from accumulating ketoacids (β-hydroxybutyrate and acetoacetate) due to insulin deficiency and increased counterregulatory hormones. The acids are produced faster than they’re buffered, bicarbonate is consumed, and the unmeasured ketoacids raise the anion gap. Clinically, patients are typically dehydrated from osmotic diuresis, and labs show hyperglycemia with ketosis and acidosis. Hyperosmolality is more characteristic of hyperosmolar states, and DKA does not cause metabolic alkalosis; dehydration is a common feature, not something that never occurs.