An obese individual is brought to the emergency room by a concerned friend. The patient has been on a self-imposed "starvation diet" for four months, and has lost 60 pounds while consuming only water and vitamin pills. If extensive blood studies were performed, which of the following would be expected to be elevated?
Long-term starvation induces many biochemical changes. Much of the body's energy requirements are normally supplied by serum glucose, but in starvation are supplied by both glucose and lipid-derived ketone bodies, including acetoacetic acid and beta-hydroxybutyric acid. Glucose cannot be synthesized from lipids, and is instead made from amino acids such as alanine in the process of gluconeogenesis. Serum alanine drops dramatically in starvation, due to its conversion to glucose. Bicarbonate levels drop as the bicarbonate buffers the hydrogen ions produced by the ketone bodies. Chylomicrons are the lipid form seen after absorption of dietary fat, and would drop because the person is not feeding. Ref: Harper's Illustrated Biochemistry, 29e; Chapter 16. Overview of Metabolism & the Provision of Metabolic Fuels
Acetoacetic acid
Alanine
Bicarbonate
Chylomicrons