Which statement is true regarding cortisol?

• A. Cortisol metabolizes free fatty acids
• B. Cortisol stimulates gluconeogenesis
• C. Cortisol stimulates protein synthesis
• D. Cortisol levels decline in stressful conditions

Answer: (C)

Cortisol is a glucocorticoid released in response to stress that shifts metabolism to provide quick energy. Its main action is to stimulate gluconeogenesis in the liver, increasing glucose production to meet the body's heightened energy needs. It does this by upregulating enzymes involved in glucose production and by supplying substrate amino acids from muscle protein breakdown and glycerol from fat breakdown. This makes cortisol a catabolic hormone, so it promotes protein breakdown rather than synthesis. It also tends to rise during stress rather than fall. So the true concept is that cortisol promotes gluconeogenesis to raise blood glucose during stress, not protein synthesis or a decline in levels.