In type 2 diabetes with glucose around 800 mg/dL, which diagnosis is most likely?

• A. Diabetic ketoacidosis
• B. Hyperosmolar hyperglycemic state
• C. Hypoglycemic coma
• D. Lactic acidosis

Answer: (B)

Hyperosmolar hyperglycemic state is characterized by extremely high blood glucose with little or no significant ketoacidosis and without major metabolic acidosis. In type 2 diabetes, especially in older individuals, enough insulin remains to prevent ketogenesis, but not enough to stop severe hyperglycemia. The resulting osmotic diuresis causes profound dehydration and raises serum osmolality, which commonly leads to mental status changes or coma. Glucose around 800 mg/dL fits this scenario well, making HHS the most likely diagnosis.

Diabetic ketoacidosis, by contrast, involves significant metabolic acidosis and prominent ketones, and it more often occurs in younger patients with type 1 diabetes. Hypoglycemic coma would present with low glucose, not high. Lactic acidosis centers on elevated lactate and acid-base disturbance, not the extreme hyperglycemia alone.