Wof bones is affected more with glucocoicoid induced osteoporosis
**Core Concept**
Glucocorticoid-induced osteoporosis (GIO) is a well-documented side effect of long-term glucocorticoid therapy, characterized by a decrease in bone formation and an increase in bone resorption. This occurs due to the imbalance in the normal bone remodeling process, where the activity of osteoclasts exceeds that of osteoblasts.
**Why the Correct Answer is Right**
The axial skeleton, particularly the vertebral bodies and ribs, is more commonly affected by GIO. This is because these bones have a higher proportion of trabecular bone (also known as cancellous bone), which is more susceptible to glucocorticoid-induced bone loss. The increased bone resorption is mediated by the activation of osteoclasts, which are multinucleated cells responsible for bone resorption. Glucocorticoids stimulate the expression of RANKL (Receptor Activator of NF-κB Ligand), a key cytokine involved in osteoclastogenesis.
**Why Each Wrong Option is Incorrect**
* **Option A:** While the appendicular skeleton (e.g., long bones) can also be affected by GIO, it is not the primary site of bone loss.
* **Option B:** The skull is relatively spared from glucocorticoid-induced bone loss due to its dense cortical bone composition.
* **Option C:** The pelvis can be involved in GIO, but it is not the most commonly affected site.
**Clinical Pearl / High-Yield Fact**
Remember the "Vertebral Body" (VB) rule: glucocorticoid-induced osteoporosis most commonly affects the vertebral bodies, which are rich in trabecular bone and are more susceptible to glucocorticoid-induced bone loss.
**Correct Answer:** C. Vertebral bodies.