USMLE (United States Medical Licensing Examination) Step 1 Practice Exam

Which metabolic derangement is commonly observed in Diabetic Ketoacidosis (DKA)?

1. Hypernatremia

2. Hypokalemia

3. Hyperglycemia

4. Hyponatremia

The correct answer is: Hyperglycemia

In Diabetic Ketoacidosis (DKA), hyperglycemia is the hallmark metabolic derangement. DKA occurs primarily in patients with type 1 diabetes, although it can also occur in those with type 2 diabetes under certain conditions. The pathophysiology of DKA involves a severe deficiency of insulin, leading to increased gluconeogenesis and glycogenolysis in the liver, resulting in very high blood glucose levels, often exceeding 250 mg/dL. Along with hyperglycemia, the breakdown of fatty acids leads to the production of ketone bodies, contributing to the acidemia that characterizes DKA. The presence of elevated ketones, along with hyperglycemia, helps to define the condition, making hyperglycemia a central feature in its diagnosis and management. In contrast, while changes in sodium and potassium levels can occur in DKA, they do not define the condition in the same primary way. Hypernatremia can occur due to dehydration but is not a defining characteristic of DKA. Hypokalemia can happen during treatment of DKA, especially after insulin administration as insulin drives potassium back into cells, but many patients initially present with hyperkalemia due to acidosis. Lastly, hyponatremia may also