Which statement best describes Hyperosmolar Hyperglycemic Nonketotic Syndrome (HHNK) compared with DKA?

• A. Significant ketosis with metabolic acidosis
• B. Minimal or no ketosis with severe hyperglycemia and hyperosmolarity
• C. Hypoglycemia
• D. Normal osmolality

Answer: (B)

Hyperosmolar hyperglycemic state features extreme high blood glucose with a very elevated serum osmolality, leading to profound dehydration from osmotic diuresis. Importantly, some insulin action remains, so ketone production is minimal or absent and there isn’t a significant metabolic acidosis. That combination—severe hyperglycemia plus high osmolality with little to no ketosis—best fits HHNK. In contrast, diabetic ketoacidosis involves marked ketosis and acidosis due to extensive ketone production, which isn’t present in HHNK. Hypoglycemia isn’t characteristic of HHNK, and the osmolality is not normal—it’s typically markedly elevated.