Problem 20 - Entrance Test

During chronic stress, persistent activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis leads to elevated cortisol levels. Which of the following is a long-term consequence of chronic high cortisol levels on the human body?

A. Increased bone density and enhanced immune function.B. Decreased blood glucose and enhanced protein synthesis in muscles.C. Suppression of the immune system and increased blood glucose.D. Improved memory and reduced abdominal fat accumulation.

Correct: C

Cortisol is a glucocorticoid hormone released by the adrenal cortex in response to stress, regulated by the HPA axis. While acute, short-term cortisol release is beneficial, chronic elevation of cortisol has several detrimental long-term effects. Key long-term effects of high cortisol: 1. **Metabolic Effects:** Cortisol promotes gluconeogenesis (glucose production from non-carbohydrate sources) and reduces glucose uptake by peripheral tissues, leading to increased blood glucose levels. It also promotes protein breakdown (catabolism) in muscles and fat redistribution (e.g., increased visceral fat). 2. **Immune System Suppression:** Cortisol is a potent immunosuppressant. Chronic high levels lead to reduced lymphocyte production, inhibition of inflammatory responses, and decreased antibody production, making the body more susceptible to infections. 3. **Bone Health:** Cortisol inhibits osteoblast activity (bone formation) and promotes osteoclast activity (bone breakdown), leading to decreased bone density (osteoporosis). 4. **Cardiovascular Effects:** Contributes to increased blood pressure. 5. **Cognitive Effects:** While acute cortisol can enhance memory, chronic high levels are associated with impaired memory, reduced neurogenesis, and increased risk of mood disorders. Let's evaluate the options: A. Increased bone density and enhanced immune function: This is incorrect. Chronic cortisol leads to decreased bone density and suppressed immune function. B. Decreased blood glucose and enhanced protein synthesis in muscles: This is incorrect. Chronic cortisol increases blood glucose and promotes protein breakdown in muscles (muscle wasting). C. Suppression of the immune system and increased blood glucose: This is correct. Chronic high cortisol levels are well-known for their immunosuppressive effects and their role in elevating blood glucose (contributing to insulin resistance). D. Improved memory and reduced abdominal fat accumulation: This is incorrect. Chronic cortisol is associated with impaired memory and increased abdominal (visceral) fat accumulation.