In DKA, what process leads to the production of ketones?

In DKA, what process leads to the production of ketones?

• A. Carbohydrate digestion
• B. Glucose uptake
• C. Protein synthesis
• D. Fat breakdown

Answer: (D)

In DKA the absence of insulin and the rise of counterregulatory hormones trigger fat breakdown. Lipolysis in adipose tissue releases free fatty acids, which travel to the liver. There, fatty acids undergo beta-oxidation to form acetyl-CoA. With low insulin, malonyl-CoA is reduced, allowing more fatty acids to enter mitochondria and be oxidized. The acetyl-CoA produced accumulates because the TCA cycle is limited by oxaloacetate being diverted to gluconeogenesis, so it is channeled into ketogenesis. This process yields ketone bodies such as acetoacetate and beta-hydroxybutyrate, which accumulate and drive the metabolic acidosis seen in DKA. So ketone production in DKA comes from fat breakdown, not carbohydrate digestion, glucose uptake, or protein synthesis.

In DKA the absence of insulin and the rise of counterregulatory hormones trigger fat breakdown. Lipolysis in adipose tissue releases free fatty acids, which travel to the liver. There, fatty acids undergo beta-oxidation to form acetyl-CoA. With low insulin, malonyl-CoA is reduced, allowing more fatty acids to enter mitochondria and be oxidized. The acetyl-CoA produced accumulates because the TCA cycle is limited by oxaloacetate being diverted to gluconeogenesis, so it is channeled into ketogenesis. This process yields ketone bodies such as acetoacetate and beta-hydroxybutyrate, which accumulate and drive the metabolic acidosis seen in DKA. So ketone production in DKA comes from fat breakdown, not carbohydrate digestion, glucose uptake, or protein synthesis.