Osteoporosis is primarily due to which imbalance between bone cells?

• A. Excessive osteoblast activity
• B. Decreased osteocyte apoptosis
• C. Cartilage degradation
• D. Excessive osteoclast activity

Answer: (D)

Bone remodeling depends on a balance between resorption by osteoclasts and formation by osteoblasts. In osteoporosis, resorption outpaces formation, so bone mass and structural strength decline, increasing fracture risk. This tilt toward resorption is driven by excessive osteoclast activity, which removes bone faster than it can be rebuilt. If osteoblast activity were excessive, bones would become denser, not weaker. Decreased osteocyte apoptosis wouldn’t by itself explain the net loss of bone mass, and cartilage degradation is not a feature of osteoporosis and doesn’t drive changes in bone density. So the primary issue is excessive osteoclast activity.